Figure 1. Initial smile.

Figure 2. Initial smile, retracted.

• Tooth No. 7. Previous root canal treatment, large composite restoration with recurrent caries, and periapical radiolucency.
• Tooth No. 8. Previous root canal treatment and large composite restoration with recurrent caries .
• Tooth No. 9. Missing tooth structure, and caries.
• Tooth No. 10. Caries.

Overall, there was uneven gingival architecture and excess overbite on teeth Nos. 7 to 10. 

Diagnoses and prognoses for the teeth were as follows:

• Tooth No. 7. Previous root canal treatment with asymptomatic apical periodontitis: hopeless.  
• Tooth No. 8. Previous root canal treatment with widened periodontal ligament: poor.
• Tooth No. 9. Recurrent caries with missing restoration: guarded.
• Tooth No. 10. Primary mesial caries: good.

Treatment Plan

A treatment plan was presented to the patient based on the findings, patient finances, and prognoses. The proposed treatment plan consisted of aesthetic crown lengthening, crown retainers (Nos. 6, 10, and 11), crown pontics (Nos. 7 to 9), and extractions with grafting (Nos. 7 to 9) (Figure 3). The goal was to maintain alveolar ridge width in the hopes of placing implants in the future after the patient has stopped growing. Risks, benefits, and alternatives were presented to the patient, and he elected to proceed with the recommended treatment under intravenous sedation (IV sedation).

Figure 3. Planning.

Procedure

On the day of the procedure, the patient came to the office NPO with a driver. Venipuncture was performed in the right antecubital fossa with a 22-ga catheter (BD Insyte Autoguard), and saline (0.9% Sodium Chloride Injection USP 500 mL [Baxter]) was attached to the catheter using an IV line (Solution Set with Duo-vent Spike 105”). The following drugs were given through the IV solution throughout the 4-hour duration of the procedure: 1 gg of Ancef, 4 mg of ondansetron, 8 mg of dexamethasone, 30 µg of toradol, 50 mg of diphenhydramine, 10 mg of versed, and 200 ug of fentanyl. Two red tubes and one white tube of blood (10 mL BD Vacutainer) were obtained using a 21-gauge butterfly needle (BD Vacutainer Safety-Lok Blood Collection Set with Pre-Attached Holder). This was placed in a centrifuge at 4,000 RPM for 14 minutes to obtain platelet-rich fibrin (PRF) clots in the red tubes and concentrated growth factor liquid in the white tube.

Two carpules of 0.5% Marcaine 1:200k epinephrine (Novocol Pharmaceutical of Canada Inc.) were used to achieve local anesthesia via infiltration injections in the maxillary anterior between teeth Nos. 6 to 11. A one-quarter carpule of 2% lidocaine 1:100,000 epinephrine (Patterson Dental) was used to achieve local anesthesia via a nasopalatine block. After achieving profound anesthesia, a 15-blade (Feather Safety Razor) and laser were used to complete a gingivectomy for teeth Nos. 7 to 10 (Figure 4). Teeth Nos. 6, 10, and 11 were then prepared for crowns using a round-end chamfer bur. Caries indicator dye was used while preparing the teeth. As tooth No. 10 was being prepared, caries appeared to extend over the pulp horn, and the decision was made to leave affected dentin as there was greater than 2 mm of clean tooth structure surrounding the area. Immediate dentin sealing was completed on tooth No. 10 by using the primer for 10 seconds, air thinning, and then placing the bonding agent (OptiBond eXTRa [Kerr]) and curing for 10 seconds (VALO Curing light [Ultradent Products]). Missing tooth structure was replaced using flowable composite (SimpliShade Bulk Fill Flowable [Kerr]) and then curing for 10 seconds. The oxygen-inhibited layer was removed by placing KY Jelly over the prep and curing for another 20 seconds. A digital impression of the maxillary, mandibular, and bite were obtained using an intraoral scanner (TRIOS 3 [3Shape]).

Figure 4. Gingivectomy.

A full-thickness sulcular incision was made from the mesio-facial line angle of tooth No. 6 to the mesio-facial line angle of tooth No. 11. An envelope flap was reflected using a molt elevator.

Crown lengthening was completed to ensure bone levels were 3 mm apical to the new gingival tissues and crown margins using a fissured surgical bur (702 FGSURG [Brasseler USA]) (Figure 5).

Figure 5. Crown lengthening after prep.

Teeth Nos. 7 to 9 were then luxated using a spade elevator (Angled Bone Preservation Elevator #60B [A. Titan Instruments]) and delivered with a #1 forcep (AtrauLux [Salvin Dental]). All sites were then curetted and irrigated with saline solution. One PRF clot was torn apart using cotton forceps and mixed with 1.0 cc of MinerOss cortico-cancellous bone size 0.60 to 1.25 mm (MinerOss [Medtronic]) and the liquid CGF to create a sticky bone mixture. The extraction sites were grafted with this sticky bone mixture, and the tissue was re-approximated using a monofilament suture with a reverse cutting needle (4-0 p-12 19 mm PGCL [AD Surgical]) (Figure 6). A digital impression of the maxilla was obtained for for the tissue profile.

Figure 6. Extractions and re-approximation.

Figure 7. Same-day printed provisional.

The scans were used to design a 6-unit fixed partial denture (FPD) using exocad software (exocad). The FPD was then printed on a SprintRay Pro 55s printer (SprintRay) using their Ceramic Crown Resin shade B1. After the print was completed in 26 minutes, the FPD was removed from the build plate, and residual resin was removed using 99% isopropyl alcohol (Florida Laboratories) and compressed air. The printed FPD was then placed in the SprintRay Procure Unit and cured for 6 minutes and 30 seconds, per the manufacturer’s guidelines. Flowable resin shade A3 (Patterson Dental Supply) was used to characterize the facial surfaces, and the FPD was polished using a Scotchbrite and rag wheels. The prosthetic was delivered using temporary cement (Temp-bond Clear [Kerr]) (Figure 7). Excess cement was removed, and the bite was adjusted for light centric contacts.

CONCLUSION

When the patient returned to the clinic for his 3-week follow-up appointment, he reported no discomfort and approved the aesthetics of the restoration (Figures 8 to 10). Local anesthesia was obtained using 4% Septocaine 1:100,000 epinephrine (Septodont Canada) via infiltrations. The sutures were removed, and the printed temporary was replaced with a zirconia restoration (Nautilus Dental Lab) using temporary cement. Temporary cement was used as the retention of the crown retainers was adequate and it would allow for further augmentation in the future if there are any changes to the soft tissue.

Figure 8. Healing at 3 weeks postoperative.

Figure 9. Smile with printed restoration.

Figure 10. Tissue contours at 3 weeks.

The patient returned to the clinic 48 hours later for follow-up photos (Figures 11 and 12). The patient reported he was happy with his new smile. This case report illustrates a workflow that highlights the use of  digital technologies for good surgical and restorative outcomes.

Figure 11. Retracted zirconia restoration.

Figure 12. Smile with zirconia restoration.

ABOUT THE AUTHOR

Dr. Yeung graduated from Virginia Commonwealth University School of Dentistry and completed a General Practice Residency at the Dental College of Georgia. He practices general dentistry in Atlanta. He can be reached via email at yeungdds@gmail.com.

Disclosure: Dr. Yeung reports no disclosures. 

Myriad clinical, functional, and aesthetic considerations converge when dentists encounter patients with insufficient vertical dimension of occlusion (VDO), collapsed bite, and excessive tooth wear.^1,2 Collaboratively with their dental laboratory, they’re faced with establishing a balanced occlusal relationship to prevent instability from influencing the longevity of planned restorations.^1-4 Simultaneously, they’re challenged to comprehensively rehabilitate a worn dentition using materials that are predictably functional and aesthetic.^3,4

Fortunately, the collaborative workflow between dentists and laboratories facilitates acquiring and sharing essential diagnostic records in a streamlined manner. Laboratories can incorporate digital bite record data into restoration design processes to more easily and precisely establish an appropriate VDO. Concurrently, they can also determine ideal restoration length in a digital wax-up to improve a patient’s occlusal relationship,^1,3,5 rather than use traditional impressions, solid models, or articulators.

The more significant implications of digital workflows and processes are the efficiencies and cost savings realized when providing these comprehensive treatments in a phased manner.⁶ Digital communication, records acquisition/transfer, and computer-aided design/computer-assisted manufacturing (CAD/CAM) of restorations culminates in rapid production of provisional restorations capable of long-term, predictable function, even when placed on implants and establishing a new occlusal relationship.^5,7

Contributing to this capability is a recently introduced printable zirconia-infused nanohybrid resin (Rodin Sculpture 2.0 [Pac-Dent]) (Figure 1). Compared to other printable materials, this zirconia-infused nanohybrid resin is highly filled (ie, 60% ceramic filler content) and, therefore, considered a permanent ceramic restorative according to ADA criteria. Its excellent mechanical properties include optimal durability, toughness, wear, fracture resistance, and a biaxial flexural strength of 200 MPa.⁸ It also exhibits desirable optical characteristics (ie, lifelike aesthetics, translucency, and ideal radiopacity).⁸

Figure 1. Rodin Sculpture 2.0 (Pac-Dent).

The following case report describes a phased treatment undertaken to increase a patient’s VDO and restore his maxillary arch. The zirconia-infused nanohybrid resin (Rodin Sculpture 2.0) was chosen for printing long-term provisional single-unit implant- and tooth-supported full-coverage crown restorations.

Case Report

A 71-year-old man presented with the chief complaint of a fractured tooth No. 8. As a pilot scheduled to fly the next day, he said he needed an immediate solution; the severity of the fracture compromised the stability of the removable partial denture currently replacing his already missing tooth No. 9 (Figures 2 and 3). A temporary restoration was placed, and an Essex retainer was made to hold the No. 8 temporary and the “flipper” for No. 9 together.

Figure 2. Preoperative full facial view of the patient after fracturing tooth No. 8; tooth No. 9 was already missing.

Figure 3. Pre-op view of the patient’s smile with his lips at rest.

Clinical Findings

Because the patient wanted to permanently restore tooth No. 8 with a full-coverage all-ceramic crown and No. 9 with an implant-supported crown, he returned to discuss definitive treatment options. However, thorough intraoral, periodontal, and radiographic examinations revealed extensive dental problems that precluded his preferred choices from clinical and financial perspectives. Heavy wear was present on the occlusal and lingual surfaces of teeth Nos. 5, 6, 8, and 10 to 12 (Figure 4). He also presented with a non-restorable, significant, and large chronic reinfection in the root canal of No. 15; a non-restorable vertical root fracture in No. 19; porcelain-fused-to-metal (PFM) restorations on teeth Nos. 2 to 4, and 13 to 15; and an implant at No. 4. 

Figure 4. After temporization of tooth No. 8, an intraoral impression scan of the patient’s maxillary arch was made highlighting occlusal and lingual wear resulting from an insufficient VDO and a collapsed bite.

Treatment Recommendations

The patient’s current condition and its implications for successful treatment were explained. He was informed that his insufficient VDO and collapsed bite rendered restoration with all-ceramic crowns impractical and unpredictable (Figure 5).^2-4 He was told that not only would he require an implant at No. 9 but also at Nos. 8, 15, and 19. Due to the wear and fracture, tooth No. 8 could not support an all-ceramic crown, and Nos. 15 and 19 were now non-restorable. He was also informed that long-term and predictable function would be predicated on opening and stabilizing his bite, which would require restoration of his entire maxillary arch.

Figure 5. Intraoral impression scan of the patient’s occlusal relationship, emphasizing the severity of his collapsed bite.

Unfortunately, the patient could not afford the total financial investment required for this treatment plan. Therefore, and particularly because he was not in pain, the prospect of phasing his treatment over several years using restorations printed from a zirconia-infused nanohybrid resin (Rodin Sculpture 2.0) was discussed with the laboratory and accepted by the patient.

Phased Treatment

According to the phased treatment plan, the oral surgeon performed the necessary extractions, then immediately placed bone grafting material and the implants at those sites, as well as at No. 9 (Table 1); the implants would remain unloaded until seating of the long-term provisionals 9 months later. After 6 months of healing, he returned for record taking (Figures 6 and 7), tooth preparation and intraoral scanning (Figure 8), and placement of a single, full-arch chairside temporary (Luxatemp [DMG America]). An intraoral scan was taken with the temporary in place.

*Zimmer; zimmerbiometdental.com

Figure 6. Close-up, retracted view of the patient’s natural occlusal relationship 6 months after implant placement.

Figure 7. The patient was photographed wearing Kois Facial Reference Glasses, which enabled accurate measurement of dentofacial proportions for creating an ideal digital mock-up.

Figure 8. An intraoral impression scan was taken of the occlusal relationship after tooth preparation for use in calculating the patient’s new VDO.

Photographs and intraoral impression scans were transferred to the laboratory to design the digital wax-up; determine the patient’s new VDO; and create the ideal size, shape, and length of the restorations to ensure proper tooth display, function, and occlusal relation.^1,3,5 Impression scans of the implant scan bodies were also captured and forwarded to the laboratory.

Because the restorations required significant wear resistance and flexural strength to withstand the patient’s occlusal forces while adapting to the increased VDO, Rodin Sculpture 2.0 was chosen. This material’s ease of repairability—should repairs ever be needed—was a noteworthy benefit compared to previously available millable and printable resin restoratives.⁹ The patient planned to maintain the provisionals for several years before pursuing all-ceramic restorations, making durability and retention significant considerations.^4,7,10 The material’s availability in 16 VITA classic shades and 2 additional bleach shades enabled the laboratory to print the single-unit, full-coverage crowns with highly aesthetic properties (Figures 9 and 10).

Figure 9. Facial view of the aesthetically characterized, printed, zirconia-infused nanohybrid resin (Rodin Sculpture 2.0) restorations on the printed model.

Figure 10. Occlusal view of the printed restorations on the printed model highlighting the implant screw access holes.

The patient returned 3 months later, at which time the temporary was removed, the preparations were cleaned, and the provisional restorations were placed. Natural tooth-supported restorations were adhesively cemented (Scotchbond Universal Adhesive and RelyX Universal Cement [3M]) according to standard protocol, and each restoration was cured from the buccal and lingual aspects for 20 seconds each. The implant-supported restorations were screwed into place, and the access holes were sealed with Teflon tape and an A2 shade direct composite (SonicFill [Kerr Dental]).

Figure 11. Occlusal view from the intraoral impression scan of the long-term provisional restorations.

Figure 12. Intraoral impression scan confirming improved occlusal/bite relationship.

Figure 13. Close-up, retracted view of the zirconia-infused nanohybrid resin restorations 10 days after placement. Note the exceptional gingival health at the margins.

Intraoral impression scans were taken to confirm restoration fit and an improved bite relationship (Figures 11 and 12). Ten days later, he returned for a followup, at which time adaptation to his new VDO and gingival margin integrity were confirmed (Figure 13). Three months later, the patient continued to experience improved function, stability, and aesthetics (Figures 14 and 15).

Figure 14. Close-up view of the patient’s natural smile 3 months after restoration placement.

Figure 15. Full facial view of the patient taken 3 months after placement of the zirconia-infused nanohybrid resin restorations (Rodin Sculpture 2.0).

CONCLUSION

Although polymethyl methacrylate (PMMA) is more frequently used for provisional restorations, its questionable flexural strength may preclude its use in long-term, phased treatments.^11,12 From the authors’ perspectives, providing this patient with long-term provisional zirconia-infused resin restorations represents a paradigm shift in how phased treatments are planned and with what materials.

The ability to confidently place adhesively bondable and reparable restorations that are printed from a material with high wear resistance and flexural strength can potentially change how—and for which patients—dentists and their teams are able to provide comprehensive rehabilitations.^9,10 Given the material’s durability, strength, and aesthetics, such treatments can now be more efficient, cost-effective, and stretched out over years, not just months.^8,10

In this case, durable single-unit crowns were placed—even on implants—to increase the patient’s VDO. This option wasn’t always possible with previously available temporary or indirect provisional restorations.^4,7,11,12 Interestingly, because the provisionals were all single units, the patient could floss between them, maintain proper oral hygiene, and ensure his gingival and overall oral health.

REFERENCES

1. Dawson P. Functional Occlusion: From TMJ to Smile Design. Canada: Mosby, Inc.; 2007. 

2. Nakamura SS, Donatelli D, Rosenberg ES. Posterior bite collapse: guidelines for treatment based on form and function. Int J Periodontics Restorative Dent. 2022;42(3):351–9. doi:10.11607/prd.5073

3. Cranham JC. Altering the vertical dimension. Dentaltown. 2020;4:70–5. 

4. Hardan L, Mancino D, Bourgi R, et al. Treatment of tooth wear using direct or indirect restorations: a systematic review of clinical studies. Bioengineering (Basel). 2022;9(8):346. doi:10.3390/bioengineering9080346

5. O’Dowling D. A simplified, completely digital workflow for full-arch temporary restorations. Dent Today. 2023;7:105–8. 

6. Sailer I. The revolution of 3D printing in dentistry. Int J Prosthodontics. 2023;36(3): 241–2. doi:10.11607liijp.2023.3e

7. Jain S, Sayed ME, Shetty M, et al. Physical and mechanical properties of 3D-printed provisional crowns and fixed dental prosthesis resins compared to CAD/CAM milled and conventional provisional resins: a systematic review and meta-analysis. Polymers (Basel). 2022;14(13):2691. doi:10.3390/polym14132691

8. Giordano R. Rodin Sculpture 2.0 third-party validation data. Boston University. Available from Pac-Dent, Brea, CA. 

9. Gad MM, Abualsaud R. Effect of repair and surface treatments on the strength of digitally fabricated resin-based dental prostheses: A systematic review of in vitro studies. J Dent. 2024;141(2):104806. doi:10.1016/j.jdent.2023.104806 

10. Alshamrani A, Alhotan A, Kelly E, et al. Mechanical and biocompatibility properties of 3D-printed dental resin reinforced with glass silica and zirconia nanoparticles: in vitro study. Polymers (Basel). 2023;15(11):2523. doi:10.3390/polym1511252 

11. Stawarczyk B, Teuss S, Eichberger M, et al. Retention strength of PMMA/UDMA-based crowns bonded to dentin: impact of different coupling agents for pretreatment. Materials (Basel). 2015;8(11):7486–97. doi:10.3390/ma8115396

12 Zafar MS. Prosthodontic applications of polymethyl methacrylate (PMMA): an update. Polymers (Basel). 2020;12(10):2299. doi:10.3390/polym12102299

ABOUT THE AUTHOR

Dr. Gillespie received his DDS degree from University of Washington School of Dentistry. He has received advanced training in cosmetic and implant dentistry as well as in IV sedation and surgical procedures. Dr. Gillespie is passionate about education and frequently lectures nationwide about several aspects of dentistry. He maintains a general practice in Vancouver, Wash, with a focus on cosmetic dentistry. He can be reached at drgreg@gillespiedentistry.com. 

Mr. Rego owns and operates Smile Designs by Rego, a progressive dental laboratory specializing in ceramics in Santa Fe Springs, Calif. He and Juan Rego, CDT, established the laboratory in 1980. He is a certified dental technician and is an accredited member of the American Academy of Cosmetic Dentistry. He has written many articles pertaining to dental materials and techniques, which have appeared in many of the leading dental journals. He is also an evaluator and speaker for several dental product manufacturers. He can be reached at nelson@regosmiles.com.

Disclosure: Dr. Gillespie and Mr. Rego report no disclosures.  

From early childhood to later stages of life, many dental patients experience a variety of treatments, ranging from basic fillings for cavities, to more complex procedures like crowns and bridges. Throughout their lives, they may also require specialized care from endodontists, orthodontists, or periodontists to maintain their oral health as they age. With an average lifespan of 77.5 years for both sexes,¹ and the percentage of older adults retaining their natural teeth on the rise,² the dental profession in the United States is seeing an older patient population presenting for treatment who have retained most, if not all, of their natural dentition. 

However, as one of the most mobile countries in the world,³ these patients have been treated by a variety of dental professionals as they relocate from one locale to the next. Whether moving to upsize or downsize their homes, change jobs, or retire to a warmer climate, it is estimated that the average American moves 11.7 times in his or her lifetime.⁴ Moving to a larger city or across state lines necessitates finding a new dentist to meet his or her prevention and treatment needs. Other issues impacting the move to a new practice may be dissatisfaction with treatment results, the retirement of the primary care dentist, or high out-of-pocket expenses. For older adults in particular, the result can be a patchwork of dentistry performed to address immediate needs, which, over a lifetime, have lost the continuity and history of previous treatment goals.

In the case presented here, an older patient in good health presented to the practice with aesthetic concerns and had all but given up on addressing her primary complaint of jaw pain after a variety of treatment modalities meant to treat it had failed.   

CASE REPORT

A 68-year-old female was referred to the practice by her husband (Figure 1). At her initial consultation, the patient recounted her dental history of orthodontic and prosthodontic treatment to relieve her TMJ pain and address aesthetic concerns. Her TMJ issues had plagued her since the age of 27 and still persisted, making her skeptical that any treatment would be successful. She was also concerned about the chipping occurring on her 2 natural central incisors (Figure 2). 

Figure 1. Preoperative photo of the patient revealing her gummy smile and lack of gingival harmony.

Figure 2. Close-up view of the anterior teeth revealed chipping on the central incisors.

A series of x-rays were taken to ensure the structural soundness and health of the patient’s teeth, gums, and bone. Preoperative photos of the maxillary arch documented that teeth Nos. 4 and 5 had been restored with crowns; No. 7 was a crown over a 30-year-old titanium implant; and Nos. 2, 3, 14, and 15 had undergone root canal treatment (Figure 3). Kois glasses also revealed a slight midline discrepancy, which would also need to be addressed (Figure 4).

Figure 3. X-rays and pre-op photos of the maxillary arch documented that teeth Nos. 4 and 5 had been restored with crowns; No. 7 was a crown over a 30-year-old titanium implant; and teeth Nos. 2, 3, 14, and 15 had undergone root canal treatment.

Figure 4. Kois glasses revealed her midline alignment would need to be addressed.

On the mandibular arch teeth, Nos. 23 to 26 had been treated with veneers, No. 19 was a crown, Nos. 20 to 22 and 27 to 29 were porcelain bridges, and natural teeth Nos. 30 and 31 were both restored with large composite fillings (Figure 5). Severe pitting on tooth No. 30 along the buccal cusp was noted, along with wear on the cusps of the other mandibular molars and crack lines on her 2 anterior central incisors (Figure 6). The patient exhibited a VDO of only 32 mm with evidence of a collapsed bite. She had a wide gummy smile (Figure 7) with poor gingival symmetry of the anterior arch.  

Figure 5. Pre-op view of the mandibular arch teeth showed that teeth Nos. 23 to 26 had been treated with veneers, No. 19 was a crown, Nos. 20 to 22 and 27 to 29 were porcelain bridges, and natural teeth Nos. 30 and 31 had both been restored with large composite fillings.

Figure 6. Although not an immediate problem, crack lines in the central incisors could cause issues in the future.

Figure 7. The patient exhibited a VDO of only 32 mm with evidence of a collapsed bite, a wide gummy smile, and poor gingival symmetry.

Treatment Proposal

In order to restore proper function and aesthetics for this patient, the first step in the treatment plan was to address her TMJ pain. To determine if a Kois Deprogrammer would be a viable treatment, load (joint) and immobility (muscle) tests were conducted and were deemed negative, indicating a Kois device would be an appropriate treatment strategy.^5-9 A Kois Deprogrammer was prescribed to restore her occlusal and temporomandibular stability and open her VDO to create restorative space for a full-mouth rehabilitation. The goal was to open her bite 1.5 mm in the posterior and restore her upper arch with crowns on teeth Nos. 2 to 15 and then, at a later appointment, restore her lower arch. A leaf gauge was used to determine centric relation. Intraoral scans of both arches (Figure 8), a bite registration, and pre-op photos were sent to the laboratory for fabrication of a Kois Deprogrammer. At the second appointment, the deprogramming device was fitted, and the patient was instructed to wear it 24 hours per day for 2 weeks except when eating.

Figure 8. After testing load and mobility tests of her jaw, a Kois Deprogrammer was prescribed to relieve her TMJ pain. Intraoral scans of both arches, a bite registration, and pre-op photos were sent to the laboratory for fabrication of a Kois Deprogrammer.

Two weeks later, the patient reported that she was free from pain and that she could now open to 45 mm. Scans of both arches of the deprogrammed jaw and a bite relation photo (Figure 9) were taken and sent to the laboratory for fabrication of a diagnostic wax-up and a putty matrix for provisionalization.

Figure 9. Post-deprogramming scans of both arches and a bite relation photo were sent to the laboratory for fabrication of a diagnostic wax-up and a putty matrix for provisionalization.

Restorative Treatment

The patient’s excessive gum display was addressed on the fourth appointment in order to achieve the desired aesthetic outcome.¹⁰ In this case, gum recession on the implant tooth No. 7 guided the crown-lengthening surgery performed on teeth Nos. 4 to 13. All paper records of the 30-year-old implant had been purged, leaving no option but to prep it for a crown with no knowledge of the implant system used and to mask the metallic substructure as best as possible. 

Figures 10 to 12. Crown-lengthening surgery for this case was guided by the gum recession on implant tooth No. 7. After 6 weeks, the gums had healed nicely.

When the patient returned 6 weeks later, the gums had healed nicely (Figures 10 to 12). The crowns on teeth Nos. 2 to 5, 7, 14, and 15 were removed and examined for underlying decay, and all teeth in the upper arch were prepared to receive all-ceramic crowns (Figure 13). Photos of the prepared patient with the stump shade were taken (Figure 14) for communication with the laboratory. 

Figure 13. The upper arch was prepared for all-ceramic pressed crowns on teeth Nos. 2 to 15.

Figure 14. A photo of the stump shade was taken to communicate with the laboratory. The key to restorative success would be masking the titanium abutment on tooth No. 7.

Figures 15 to 17. The upper arch was provisionalized, and the patient was instructed to wear the provisionals for a month to test fit, function, and aesthetics.

Using the putty matrix supplied by the laboratory, provisionals (Structur 2 SC Self Cure [VOCO]) were fabricated for both arches chairside and spot-etched and bonded in place (Adhese [Ivoclar]) (Figures 15 to 17). For the mandibular arch, all existing restorations were removed, and the teeth were provisionalized without prepping to ensure the patient functioned well with her new centric relation. The patient approved the aesthetics of the provisionals and was advised to wear them for one month to test the function and fit as well as to ensure her jaw pain was no longer an issue. 

After wearing the provisionals for a month, she returned to the practice pleased with the aesthetics and functional outcome of the treatment and reported no jaw pain was present. A scan of the upper arch, along with photos with a tooth shade tab (Figure 18) and a bite stick photo were sent to the laboratory to fabricate the final restorations (IPS e.max Press shade M1 [Ivoclar]).

Figure 18. A photo of the provisionals with a shade tab was taken to communicate with the laboratory.

Figures 19 to 22. The final maxillary restorations were delivered and seated.

On delivery, the final restorations for the maxillary arch were seated (Variolink Esthetic DC Neutral [Ivoclar]) (Figures 19 to 22). The following day, the teeth in the mandibular arch were prepared and provisionalized. Upon delivery, the final mandibular restorations were seated (Variolink Esthetic DC for crowns and Variolink Esthetic LC Neutral for veneers [Ivoclar]), and the patient was pleased with the final outcome. A month later, she returned for a follow-up appointment, and final photos were taken of the case outcome (Figure 23).

Figure 23. Three weeks after the final mandibular restorations were seated, the patient returned to the practice for final photographs.

CONCLUSION

Often, patients present to the practice disappointed by past dental work and have lost faith and trust in the profession in treating long-standing problems. Taking them to the point of accepting treatment involves rebuilding that trust and helping them overcome their fear of the process. Approaching these patients with concern and compassion and focusing on relieving long-standing issues before rehabilitating the aesthetics of their smiles can restore that trust and belief in the profession.

The patient’s reaction sums up the outcome of this case: “No doubt my case brought with it obstacles and challenges. As a patient, coming to the decision of going forward with a full restoration is actually a big decision. Turning oneself over to the process involves trust and letting go of fear. I came to you to change, improve, and restore my smile. You did that and far more by providing me with a professional, all-encompassing plan of action to correct and restore long-standing problems. I remain grateful and appreciative. Thank you kindly.”

ACKOWLEDGMENTS

Dr. Desai would like to thank ceramist, Juan Rego, from Smile Designs by Rego (regosmiles.com) for the collaboration and ceramic work. 

REFERENCES

1. Kochanek KD, Murphy SL, Xu J, et al. Mortality in the United States, 2022. NCHS Data Brief. 2022;(492):1-8.

2. Centers for Disease Control and Prevention. Oral Health Surveillance Report: Trends in Dental Caries and Sealants, Tooth Retention, and Edentulism, United States, 1999–2004 to 2011–2016. Atlanta, GA: Centers for Disease Control and Prevention, US Dept of Health and Human Services; 2019. 

3. Plumer B. Americans still move around more than anyone else in the world. Washington Post. May 15, 2013. 

4. Chandler A. Why do Americans move so much more than Europeans? Atlantic Monthly. October 21, 2016. 

5. Gaikwad A. Effects of different deprogramming devices on electromyographic activity of masseter and temporalis muscles: A crossover clinical study. J Indian Prosthodont Soc. 2020;20(Suppl 1):S9-S10. doi:10.4103/0972-4052.306365 

6. Kois JC, Hartrick N. Functional occlusion: Science-driven management. J Cosmet Dent. 2007;23(3):54–7. 

7. Jayne D. A deprogrammer for occlusal analysis and simplified accurate case mounting. J Cosmet Dent. 2006;21(4):96-102. 

8. Beshar MJ. Systematic treatment using a direct deprogrammer to resolve long-standing problems in a phobic patient. Compend Contin Educ Dent. 2015;36(6):418, 421–5. 

9. Ohyama H, Nagai S, Tokutomi H, et al. Recreating an esthetic smile: a multidisciplinary approach. Int J Periodontics Restor Dent. 2007;27(1):61–9. 

10. Kois JC. Altering gingival levels: The restorative connection part I: Biologic variables. J Esthet Restor Dent. 1994;6(1);3-7. doi:10.1111/j.1708-8240.1994.tb00825.x

ABOUT THE AUTHOR

Dr. Desai, a graduate of the Kois Institute, holds degrees in dental hygiene and dental surgery from the University of Southern California. She is an accredited member of the American Academy of Cosmetic Dentistry, a distinction shared by only a select few globally. Dr. Desai has also been recognized as a top dentist in Orange County for the past 5 years and was named one of the Top 40 Dentists under 40 in the nation. Her contributions to the field include publications in prestigious dental journals and speaking engagements, leveraging her expertise to advance dentistry. Dr. Desai founded Luminous Smiles of Newport Beach, Calif, a boutique dental practice focused on enhancing patients’ smiles. She can be reached at drdesai@luminoussmiles.com. 

Disclosure: Dr. Desai reports no disclosures.  

Internal bleaching is a highly sought-after treatment and a great service to provide to patients. External bleaching differs from internal bleaching in the sense that external bleaching addresses superficial staining, while internal bleaching manages internal discoloration. External bleaching is generally applied to the entire dentition, but internal bleaching may only target one or a few teeth. 

There are several reasons a tooth may become internally discolored: pulp necrosis, intrapulpal hemorrhage, retention of pulp tissue at the time of root canal therapy, calcific metamorphosis, or internal resorption.¹ Other available treatment options to address discoloration include porcelain veneers and composite veneers with the use of opaquer. The advantage of internal bleaching is that it generally conserves tooth structure. Additionally, managing a discolored tooth with porcelain can present unique challenges. Teeth typically become darker as they are being prepared for a veneer. This can present a challenge to the ceramist to mask the discoloration when creating the veneer. 

Composite with opaquer is an excellent option for masking a discolored tooth; however, this treatment modality also presents with its own unique challenges due to its technique-sensitive nature. The challenge involved with using opaquer is that it raises the value of the restoration. The clinician must be very mindful not to overuse opaquer to the extent that the tooth no longer matches the surrounding dentition and the tooth looks lifeless. 

All things considered, internal bleaching also presents obstacles. The final outcome of the bleaching is not always guaranteed, and it may require multiple visits, depending on the technique utilized. Internal bleaching is, however, very safe. Historically, the “walking bleach” technique, a form of internal bleaching, was done with heated superoxol, which presented a considerably higher risk of resorption than modern sodium perborate or carbamide peroxide. 

CASE REPORT 

A 50-year-old female presented seeking treatment for a discolored No. 9. A shade-matching photo was promptly taken with a DSLR camera and macro lens (Canon 80D). VITA shade tabs were used to gauge the patient’s current tooth shade (A3.5) (Figures 1 and 2). It is important that the photo is taken quickly and before the tooth dehydrates. The value of a tooth is artificially raised as it becomes dehydrated. This may lead to an incorrect color match. Gathering the initial shade is helpful for tracking the progress of the bleaching therapy. A patient may feel that the bleaching has been unsuccessful but may gain new faith in the process when he or she sees before and after photos. 

Figures 1 and 2. The initial presentation of No. 9.

It is vital for the clinician to determine the pulpal diagnosis prior to bleaching or restorative treatment. This may determine the treatment option the patient is best suited for. In the event the tooth still remains vital, the clinician may consider using a restoration to mask the dark tooth. Internal bleaching requires RCT, which some patients may not be amenable to. Additionally, in the event RCT has been previously completed, it needs to be determined whether or not the existing RCT is acceptable. The clinician should evaluate the fill, taper, and density of the obturation. In the event the previous treatment is not satisfactory, it should be re-treated prior to the completion of internal bleaching. Finally, a periapical diagnosis of the tooth should be determined prior to treatment. Although the RCT may appear acceptable, the patient may have an underlying periapical pathology (such as asymptomatic apical periodontitis or a chronic apical abscess) that should be ruled out prior to elective treatment.  

A periapical radiograph was taken and reviewed of No. 9. This tooth had a previously completed RCT with a poor fill, taper, and density (Figure 3). No. 9 responded non-tender to percussion and palpation, and all probing depths were 3 mm or less. The poor existing fill, taper, and density warranted the RCT to be re-treated. A failure to redo the RCT can be thought of as building a house on “sinking sand.” A tooth should be free of disease or pathology prior to the placement of a restoration or internal bleaching. 

Figure 3. A periapical radiograph was taken of No. 9 in order to gauge the pulpal and periapical diagnosis and assess the quality of the root canal therapy.

The patient was then presented with several treatment options, including internal bleaching, a porcelain veneer, and a composite veneer. The risks and benefits were thoroughly reviewed, and she elected for internal bleaching. 

The author completed the root canal therapy retreatment and then placed an orifice barrier with Vitrebond (3M) (Figure 4). The orifice barrier was placed at the level of the CEJ. If the orifice barrier is placed too far incisally, it will cause the cervical third of the tooth to not completely bleach. Alternative RMGIs that could have been used are GC Fuji II LC (GC) and BC Liner (Brasseler). The advantage of BC Liner is that it can come in a blue shade, which facilitates better identification of the orifice barrier in case of an RCT re-tx.

Figure 4. After RCT was completed, an orifice barrier was placed at the level of the CEJ with with an RMGI.

Next, any remaining core material was removed from the chamber under rubber dam isolation. This step is challenging but perhaps one of the most critical because it can be difficult to discern where the restorative material begins and ends. Failure to remove any core material completely will prevent the tooth from bleaching completely. If it is noticed that the internal bleaching is entirely ineffective, it may be because of the residual core build-up material. Clinicians should be particularly careful when removing the core material because it may result in a perforation of the facial tooth structure. 

Different techniques for identifying remaining restorative material include (1) scratching the material, (2) placing phosphoric etch over the composite, (3) using a black light pen, and (4) taking a radiograph. Many core materials and composites, but not all, will display a black scratch when scratched with an explorer. Phosphoric-etch placement can also be used because it alters the optical properties of the composite. An inexpensive black light pen is useful as long as the composite has additives that fluoresce; not all composites have this additive.² A periapical radiograph can also be taken if the operator is unsure if any composite remains. But even this step may be thwarted if the chamber is filled with a microfill composite, which typically lacks a radiopaque additive. In effect, it should be noted that the clinician should be prepared to utilize a range of techniques because no technique is guaranteed to be successful. In this case, the core was restored with a resin composite material that fluoresced, so a black light pen was used to remove all the composite.

Next, sodium perborate was crushed and moistened with water so that it had the consistency of wet sand. It was then placed in the chamber, and the access was sealed with Cavit (3M) (Figure 5). Alternatively, it could have been sealed with GC Fuji TRIAGE (GC), but the downside of this material is that because it bonds to tooth structure, it is more time-intensive to remove. In order for internal bleaching to be profitable for the clinician, replacing the bleach at follow-up appointments needs to be quick. The ratio of Cavit to bleach should also be weighed carefully by the practitioner. The advantage of having a thin layer of Cavit over the access is that there is more room for the bleach to be effective. But the downside is that the thin temporary material may be more likely to fall out. Neither the clinician nor the patient should be too concerned if the barrier falls out as long as a sound orifice barrier is in place.

Figure 5. After crushed sodium perborate was placed in the chamber, the chamber was sealed with Cavit (3M).

The patient was instructed not to incise on No. 9 until treatment was completed and a definitive core could be placed. The patient was reappointed for the bleach to be replaced within 7 days. Clinicians should anticipate that they will be replacing the bleach about every 5 to 10 days for about 2 to 4 appointments. 

Figure 6. A follow-up shade-matching photo was made after the 3 rounds of internal bleaching using the “walking bleach” technique with sodium perborate.

After 3 rounds of internal bleaching with sodium perborate, No. 9 failed to respond to treatment (Figure 6). All variables as to why No. 9 failed to respond to sodium perborate were ruled out. The expiration date on the material was re-verified, and a periapical radiograph was taken to ensure all composite core material had been removed. 

A second bleaching technique was employed. A rubber dam was placed over No. 9, and 40% hydrogen peroxide (Opalescence Boost PF 40% HP In-Office Power Whitener [Ultradent Products]) was placed inside the chamber and on the outside according to the manufacturer’s instructions (Figure 7). It should be noted that, per the manufacturer’s instructions for use, this material is also intended for internal, nonvital bleaching. This product was not used off-label. Once the in-office whitening was completed, the chamber was sealed with Cavit, and the tooth was given 3 days to rehydrate in order to determine the new shade. The attempted in-office bleaching also achieved a minimal increase in value (Figure 8).

Figure 7. In-office bleaching was attempted on No. 9 following the manufacturer’s instructions.

Figure 8. A follow-up photo was taken of No. 9 to gauge the progress of bleaching following the in-office treatment.

A third technique was employed to internally bleach No. 9. The “inside-outside” bleaching technique, which involves at-home external and internal bleaching, was attempted. In this technique, the orifice barrier is left intact, but the chamber is removed of any temporary materials and thus left hollow. Clinical data has demonstrated that this technique is as safe and effective as the walking bleach technique.³ Next, the patient was given a bleaching tray and instructed to fill the chamber and external surface of No. 9 with 10% carbamide peroxide (Opalescence 10%-Carbamide Peroxide [Ultradent Products]) (Figures 9 and 10). The patient was instructed to remove the bleaching tray when eating and drinking and to rinse out the chamber with water (using a Monoject syringe [Cardinal Health]) before and after eating. In order for this technique to be effective, patient compliance is paramount. The patient must ensure the chamber is free of debris before filling it with bleach. She was also carefully instructed to avoid incising on No. 9 because it was hollow and particularly brittle. Once she was done eating or drinking, she was to refill the chamber and external surface of No. 9 with the bleaching gel. The patient was then dismissed and returned 21 days later. 

Figure 9. Ten percent carbamide peroxide was placed in the chamber of No. 9.

Figure 10. The patient wore a bleaching tray with carbamide peroxide that was placed in the chamber and on the external surface of the tooth. It should be noted that No. 9 appeared translucent on the facial surface because Cavit was not cur- rently in the chamber. In previous images of No. 9, Cavit was in the chamber, which made the facial appearance of No. 9 look less translucent. The facial surface of No. 9 was translucent due to the removal of the core material.

It is the author’s opinion that case selection for the inside-outside technique is a key factor in success. Only patients who demonstrate they will be compliant should be selected. The patient is responsible for keeping the chamber clean and faithfully applying bleach. 

Following completion of the treatment, her desired outcome was finally achieved (Figure 11). The chamber was then temporarily filled with Cavit once more for 2 weeks prior to placement of the final restoration. A tooth should never be restored immediately after bleaching but rather 10 to 14 days later.⁴ After 14 days, the chamber of No. 9 was restored with a bleach shade resin composite under rubber dam isolation. Restoring the chamber with a bleach shade composite is an important final step for success in achieving patient satisfaction.

Figure 11. The final postoperative photo of No. 9 after the completion of bleaching.

The hypothesized reason as to why the inside-outside technique achieved a favorable outcome over the other techniques is that No. 9 was continuously being exposed to fresh bleach for a lengthy period of time. The downside of using sodium perborate in the walking bleach technique is that the efficacy of the material decreases over time. Although the in-office technique utilizing 40% hydrogen peroxide involved a high concentration of bleach, the tooth may not have been exposed to the bleach for enough time.

ACKNOWLEDGMENT

Special thanks to Dr. Jason Smithson for introducing me to this technique.

REFERENCES

1. Hattab FN, Qudeimat MA, al-Rimawi HS. Dental discoloration: an overview. J Esthet Dent. 1999;11(6):291-310. doi:10.1111/j.1708-8240.1999.tb00413.x 

2. Brauer, J. The scorpion technique: a veneer-seating pearl. Dent Today. 2024;43(1):97-99.

3. Pedrollo Lise D, Siedschlag G, Bernardon JK, et al. Randomized clinical trial of 2 nonvital tooth bleaching techniques: A 1-year follow-up. J Prosthet Dent. 2018;119(1):53–9. doi:10.1016/j.prosdent.2017.03.004

4. Attin T, Hannig C, Wiegand A, et al. Effect of bleaching on restorative materials and restorations—a systematic review. Dent Mater. 2004;20(9):852–61. doi:10.1016/j.dental.2004.04.002 

ABOUT THE AUTHOR

Dr. Seibert is the deputy program director for the AEGD residency at Langley Air Force Base in Virginia and a clinical instructor at the University of Creighton School of Dentistry. She is the creator and host of the Dental Digest podcast, a podcast in the top 1% of all podcasts globally. She lectures to national and international audiences and has multiple publications related to clinical dentistry. She was recently named a top 40 under 40 dentist in America by Incisal Edge magazine. She can be reached at dr.melissaseibert@gmail.com.

Disclosure: The views expressed are those of the authors and do not reflect the official views or policy of the US Air Force, Uniformed Services University, Department of Defense, or its components. The author does not have any financial interest in the companies whose materials are discussed in this abstract. 

Complex cases can be challenging for a variety of reasons, such as patient demands, budgetary constraints, clinical conditions, and so on. When facing cases of this type, which many dental practitioners will immediately recognize as typical, a team approach between the dental practitioner and the dental laboratory is best. Along with using basic new technologies at our disposal, the team can aid in eliminating potential challenges to achieving the desired results that satisfy the patient’s expectations and budget while decreasing the practitioner’s stress levels. 

In addition to identifying a solid lab partner to handle the case, the dental practitioner can also take advantage of the advancements in cementation, restorative materials, and dental laboratory virtual planning technology to achieve results that satisfy the patient’s expectations while avoiding the stresses that can arise from complex cases.  

In this case, a patient presented with a situation not all too unusual in dentistry—a blend of clinical issues, conditions lost to time, and high expectations to have it addressed to her specific needs and budget. In this circumstance, the choice of lab, materials, and cementation enabled a consistent and predictable workflow for the patient that mitigated stress for the practitioner, team, and patient.

SETTING THE COMPLEX CASE UP FOR SUCCESS

Choosing the Laboratory

When choosing the dental laboratory you want to work with, using virtual planning tools is critical to improve communication between the practitioner and lab so that the patient’s expressed aesthetic and functional goals can be achieved with minimal stress. The lab should also be able to furnish a provisional to “test-drive” the aesthetics and function to allow the patient to express any changes he or she may want prior to fabrication of the final prosthetics. With virtual design incorporating those changes, the lab can quickly make the requested changes and allow the practitioner to see a virtual model before the lab fabricates the restorations. Those changes may include midline placement and angulation, vertical dimension of occlusion (VDO) increases or decreases, and/or shade changes. Virtual planning capabilities with the laboratory are essential.

Prosthetic Planning Choices

Zirconia restorations are increasingly being used both with natural teeth and implants as either single units, partial arches, or full-arch prosthetics. Cementation to zirconia has, in the past, been a potential issue to achieve a good bond to the zirconia. Some routinely used cements (such as glass ionomers) have minimal, if any, real bond to the zirconia surface, and debonding becomes a potential issue over time. Resin cements have been recommended to prevent debonding and are commonly used for this application. Therefore, the selection of a resin cement with high bond strength to zirconia is important. Additionally, the use of a resin cement that has high bond strength to metal eliminates potential debonding between the cement and the abutment head.

One challenge when cementing to implant abutments vs natural teeth is a snugger fit of the prosthesis to the abutments when multiple units are being restored (partial- or full-arch restorations) than typically observed with natural tooth preparations. Thus, the utilization of resin cement with a low film thickness allows full seating of the restorations without the cement potentially preventing that seating. The author suggests, especially when cementing a restoration on an implant abutment, to not fill the interior of the abutment with cement as this may prevent full seating of the restoration due to hydraulic pressure as the cement pools at the coronal of the abutment. Placement of cement on the interior marginal area of the abutment crown permits full seating as the cement spreads coronally as the restoration is seated. 

BruxZir Dual Cure Resin Cement (Glidewell) fulfills the goals discussed. The resin cement has high bond strengths to dentin and etched enamel without the need for a separate bonding agent. Additionally, its high bond strengths to various restorative materials allow its use with metal-based restorations, metal implant abutments, various ceramics in use for restorations, and zirconia. The cement’s high compressive strength and shear bond strength allow its use for any clinical situation and crowns, bridges, and veneers that require cementation. BruxZir Dual Cure resin cement is well-suited for cementation of zirconia, helping eliminate potential debonding of the restoration from the underlying tooth or implant abutment. 

CASE REPORT

An 80-year-old female patient of the practice presented after an absence related to the pandemic and family health issues indicating several teeth had broken. The patient had previously been treated in the author’s practice with implants in the maxillary left posterior and posterior bilaterally in the mandible. The examination noted several remaining teeth had fractured (Nos. 5, 9, 10, 11, and 21), of which several had prior endodontic treatment, and the crowns had been lost. Mobility of Grade 1 was noted on teeth Nos. 22 to 26. The implant crown on No. 14 was missing. 

A panoramic radiograph was taken to evaluate the teeth and implant present (Figure 1). Evaluation of the radiograph noted recurrent decay on the crowns of teeth Nos. 7 and 27, which had prior endodontic treatment, and a periapical lesion was noted on No. 27. Those natural teeth were in poor condition and would not be restorable. Bone levels on the existing implants at Nos. 12, 14, 15, 19, 20, and 28 to 30 demonstrated no crestal bone loss. 

Figure 1. The patient presented with fractured teeth and periodontal bone loss on the remaining teeth in both arches.

The patient expressed a desire to replace the natural teeth with implants to reduce the risk of additional potential problems vs attempting to restore the remaining natural dentition. 

The patient indicated she wished to be sedated during the extractions and implant placement due to her exaggerated gag reflex. With that in mind, she would be referred to an oral surgeon who would perform the extractions and implant placement under the desired sedation. A treatment plan was formulated to place implants at sites 3, 5, 8, 9, and 11 in the maxilla and 21, 24, and 27 in the mandible. Restoration would consist of custom abutments in both arches and restoration with BruxZir monolithic cementable bridges on Nos. 3 to 11 and 21 to 27, with a single crown at No. 14. 

Impressions were taken, and provisional partial dentures were provided as the plan was not to immediately load the implants due to her age and concern about bone density. The patient was given a referral to the OMFS, and a consultation appointment with them was scheduled for her. 

The provisional partial dentures were returned from the lab. The OMFS office was notified that we had them and to have the patient scheduled with our office to insert them a few days following her implant placement appointment. The patient was treated under sedation, wherein the remaining teeth were extracted. AnyRidge implants (Mega’Gen USA) were placed as follows: No. 3: 5 × 10 mm, No. 5: 4 × 11.5 mm, No. 8: 4.5 × 11.5 mm, No. 9: 4.5 × 11.5 mm, No. 11: 4 × 11.5 mm, No. 21: 3.5 × 11.5 mm, No. 24: 3 × 10 mm, and No. 27: 4 × 11.5 mm. Cover screws were placed with primary closure over the implants being achieved.           

The patient presented 4 days following extractions and implant placement with the implants covered with soft tissue. The provisional partials were tried in, adjusted, and relined with COE-COMFORT tissue conditioner (GC). The design of the maxillary partial was with a minimal horseshoe palatal coverage due to her exaggerated gag reflex. The patient was scheduled a week later to check the provisionals. She presented for that appointment indicating she was having issues with gagging and, after a day or 2, decided not to wear the provisionals and consume a very soft diet. During a discussion with the patient, she indicated she would prefer not to wear any provisionals and was functioning well without them. She was scheduled to return in 2 weeks to check soft-tissue healing and see if she was having any issues with eating without the use of the provisionals. At that appointment, she again indicated she was functioning well without the provisionals and was comfortable until her appointment to uncover the implants to initiate the restorative phase of treatment.

The patient was scheduled to see the OMFS at 4 months for implant uncovery, wherein he uncovered the implants under local anesthetic and placed healing abutments. The restoration was missing on implant No. 12. A panoramic radiograph was taken, and it was noted that the screw on No. 12 had fractured in the implant (Figure 2). A modification was made to the treatment plan for the maxillary arch. The crown would be removed on implant No. 15, and No. 12 would be buried with the full-arch restoration, including the current abutments on Nos. 14 and 15, to yield a zirconia bridge from Nos. 3 to 15. 

Figure 2. The panoramic radiograph following extraction of the natural teeth and implant placement after a 6-month healing period. The restorative phase of treat- ment was ready to be initiated.

After a soft-tissue healing period of 2 weeks, the patient returned to initiate the restorative phase. The crown was removed from implant No. 15, leaving its abutment on the implant. The healing abutments were removed, and closed-tray impression copings were inserted into each implant. Periapical radiographs were then taken to confirm full mating of the prosthetic part and the implant connectors. An impression was then taken in a full-arch tray of both arches utilizing NoCord light-body VPS (Centrix Dental) injected around the tissue aspect of each coping, and the tray was filled with NoCord MegaBody VPS (Centrix Dental). Upon setting, the trays were removed, impression copings were removed intraorally, and the healing abutments were reinserted. The provisional partial dentures would be utilized to capture the bite and occlusion. They were inserted, Access BLUE Bite VPS (Centrix Dental) was expressed over the occlusal surfaces, and the patient was guided into occlusion. Upon setting, the bite registration and provisional partials were removed as one unit to be sent to the lab.

The impressions, bite registration, and implant analogs with copings were sent to the lab (Glidewell) to start the prosthetic fabrication. A lab prescription was sent requesting custom abutments for implant Nos. 3, 5, 8, 9, 11, 21, 24, and 27. Additionally, provisional fixed restorations were requested to fit the custom abutments for Nos. 3 to 15 and 21 to 27. Soft-tissue models for both arches were fabricated at the lab utilizing the closed-tray impressions sent (Figure 3). These were then mounted on an articulator using the bite registration and provisional partial dentures (Figure 4). 

Figure 3. Soft-tissue models were created at the lab utilizing the open-tray impressions that had been sent.

Figure 4. The soft-tissue models were then mounted on an articulator using the bite registration and provisional partials.

Figure 5. Virtual models were imported into exocad (exocad) to start virtual design of the custom abutments and provisional bridges.

Figure 6. Virtual design of the abutments for cementable restorations for both arches.

Figure 7. Virtual design of provisional restorations to verify aesthetics intraorally.

Glidewell’s laboratory technicians scanned the soft-tissue models, created virtual models, and imported them into the lab’s system (Figure 5). Custom abutments were designed for the implants to be parallel with each other and the abutments on the old implants at Nos. 14 and 15 (Figure 6). Those were then individually milled from titanium on the Haas 5-Axis milling unit. They were then polished and finished. Next, virtual provisional bridges were designed to fit the virtual abutments previously designed in the lab’s system (Figure 7). Two sets of provisional bridges were milled in shade B2 using polymethyl methacrylate resin (BioTemps) on a Glidewell mill. One set would be used to capture a new bite registration intraorally and note any aesthetic changes desired, while the other set would be used as provisional restorations, allowing the patient to “test-drive” the aesthetics and occlusion. The custom abutments and resin placement jigs with the provisional bridges were returned to the office. 

Figure 8. Maxillary abutments on the soft-tissue model (left) and with an abutment placement jig seated over the abutments on the model (right).

Figure 9. Custom abutments were tried in, and seating was then verified radiographically.

The patient returned, and the healing abutments were removed intraorally from the anterior mandibular implants. The placement jig for the maxillary arch was placed on the abutments on the soft-tissue model, and the screws were removed from the abutments (Figure 8). The jig was transferred to the mouth and seated on the mandibular implants. The screws were inserted and finger-tightened. Periapical radiographs were taken to verify full seating of the custom abutments at the implant connectors. Upon verification, the screws were tightened to the implant manufacturer’s specifications with a torque wrench. This was then repeated on the mandibular arch (Figure 9). The provisional bridges were tried in over the custom abutments intraorally to verify full seating. The patient was shown a mirror, and she indicated she was happy with the shade. It was noted that the maxillary midline was tipped to the right, and that would be corrected in the final restorations. Photos were taken to communicate with the lab technicians (Figure 10). Teflon tape (PTFE) was placed into the screw access holes on the abutments to prevent cement contact with the screw heads. The provisionals were then cemented with NexTemp Temporary Cement (Premier Dental), and the patient was dismissed to “test-drive” the aesthetics for a few days. Four days later, the patient was called and asked if she was happy with the aesthetics and if she desired any changes. She expressed satisfaction with the shade and general aesthetics. We suggested decreasing the VDO so that less maxillary teeth showed when smiling, and she accepted that recommendation and the one to adjust the maxillary midline.  

Figure 10. Provisional restorations were tried in to allow the patient to aesthetically “test-drive” the restorations before any potential changes would be communicated to the lab.

Figure 11. Modifications were made in the virtual design to decrease the VDO, at the expense of the maxillary arch, and change the angle of the midline to a more vertical axis.

Figure 12. Virtual design of the maxillary and mandibular BruxZir monolithic bridges (Glidewell).

Upon receipt of the clinical photos, the second set of provisionals with midline angle correction was marked with a Sharpie marker, and we requested the lab tech also decrease the VDO at the expense of the maxillary arch and design the final prosthetics (Figures 11 and 12). The final bridges were milled from BruxZir Monolithic Zirconia (Glidewell) on a 5-Axis milling unit (Haas). Following milling, support legs were removed, and those areas were ground and polished, and then the bridges were fired to complete them (Figure 13). Stain was then applied to match the gradations on the VITA shade tab for B2 to achieve a natural appearance and eliminate a monochromatic aesthetic (Figure 14). The stained BruxZir bridges were fired, then glazed (Figure 15) and re-fired to finalize the monolithic bridges (Figure 16).

Figure 13. Maxillary final BruxZir full-arch and mandibular anterior BruxZir-cemented restorations following milling and processing.

Figure 14. The lab applied stain to the fired BruxZir restoration for characterization and verified it with the selected shade tab.

Figure 15. The lab applied glaze to the BruxZir restoration following baking the stain to finish the cementable implant bridge.

Figure 16. The final glazed and stained BruxZir restorations.

Figure 17. Placement of BruxZir Dual Cure Resin Cement (Glidewell) into the abutment crowns on the BruxZir bridge in preparation for cementation.

Figure 18. Final BruxZir maxillary full-arch and mandibular anterior bridge following luting with BruxZir Dual Cure Resin Cement and demonstrating final aesthetics.

The patient returned to the office, and the provisional bridges were removed intraorally. Any residual temporary cement was cleaned from the abutments intraorally. The BruxZir monolithic bridges were tried in to confirm passive seating over the implants on each arch. The occlusion was verified, and no adjustments were made. The patient indicated the bite felt even and comfortable. The interiors of the abutment crowns on each bridge were dried with a cotton pellet. BruxZir Dual Cure Resin Cement was placed into abutment crowns on each bridge at the interior marginal area, not filling the area so that, upon placement, the cement would not prevent full seating (Figure 17). The implant abutments were dried with gauze, and the bridge was seated fully on the maxillary arch. This was repeated with the mandibular bridge, and the patient was guided to bite into cotton rolls placed bilaterally in the posterior as well as one in the anterior. Following the setting of the resin cement, the cotton rolls were removed, and excess cement was marginally removed with a scaler. The patient was asked to occlude and indicated the bite felt even and comfortable. She was shown a mirror and indicated she was happy with the aesthetics, noting that it looked natural to her (Figure 18). The patient was scheduled for a post-insertion appointment at one week to check and confirm the occlusion after she had time to function with it.

CONCLUSION

Complex treatments, especially when a full arch is being treated, can provide challenges to achieve the patient’s desired aesthetic goals. The team approach aids in achieving the planned goals while decreasing stress on the practitioner, resulting in a satisfied patient at the completion of treatment. As outlined in the case presented, planning needs to follow each patient’s expressed treatment requests with regard to aesthetics and function. Additionally, in complex cases, when placing implants on an arch where previously placed and restored implants are present on natural teeth that were not being treated, changes may result during the treatment process that require modifications in the treatment plan. Coordination with the lab team aids in incorporating necessary changes as they may arise. 

Cementation of zirconia restorations has posed a challenge in the past, with the potential of debonding from the zirconia being a common occurrence. BruxZir Dual Cure Resin Cement has high bond strengths to dentin, etched enamel, metal (metal-based restorations or implant abutments), ceramics, and zirconia, allowing its use in any clinical application that requires cementation.

ACKNOWLEDGMENTS

The author would like to thank Dr. Anis Tebyanian, for the oral surgery aspects of the case presented, and the following Glidewell technical experts who assisted through the planning and execution of the discussed case: Catalina Bollman, senior manager, dental production; Luis Rodriguez, CAD/CAM scanner; Jorge Espinoza, CAD/CAM designer; Isaiah Porter, quality control, final; Steve Tran, cement technician III; Nhi Tran, dental technician; Danny Nguyen, CAD/CAM design technician; Mike Lee, manager, dental production; Haiping Li, glaze team leader; Celine Jun, stainer; and Erik Baltazar, manager, dental production. Thank you!

ABOUT THE AUTHOR

Dr. Kurtzman is in private general practice in Silver Spring, Md. A former assistant clinical professor at the University of Maryland, he has earned Fellowships in the AGD, the American Academy of Implant Prosthodontics, the American College of Dentists, the International Congress of Oral Implantologists (ICOI), the Pierre Fauchard Academy, and the Association of Dental Implantology; Masterships in the AGD and ICOI; and Diplomate status in the ICOI and the American Dental Implant Association. He has lectured internationally, and his articles have been published worldwide. He has been listed as one of Dentistry Today’s Leaders in Continuing Education since 2006. He can be reached via email at dr_kurtzman@maryland-implants.com.

Disclosure: Dr. Kurtzman reports no disclosures. 

Clinical procedures concerning the need for posts and the protocol for core buildups in endodontically treated teeth have evolved significantly over the last few decades with the advent of dentin bonding protocols. Likewise, the dental literature has evolved yet is fraught with contradictions. However, the consensus in the literature today is that posts weaken teeth, and when adequate tooth volume is present, a post is contraindicated, and only a core buildup should be done. 

There is a misconception often quoted in the literature that the reason a post is needed is to retain the core buildup. Perhaps this was true before adequate dentin bonding protocols existed, but this is simply no longer true. Posts cannot retain a buildup because the post itself is retained by the cement and buildup. Posts have no inherent retention. The only reason to place a post is to avoid horizontal fracture of the core buildup. In addition, many authors subscribe to the necessity of the ferrule effect, while others debunk the idea. Many clinical studies on the ferrule effect are simply studying residual tooth structure volume rather than any effect ferrules may have. Clinical decisions on how to best restore endodontically treated teeth must be made with a jaundiced eye toward the literature since there are so many contradictions in the “evidenced-based” literature.

Much of the conflict in the endodontic literature on post placement stems from the clinical protocols used in the studies. Any study done using paper points to dry a canal where dentin bonding is used is flawed because paper points simply will not sufficiently dry a canal for dentin bonding to work. Studies done with acid-based cements that do not bond to the unique post space dentin and the post are also flawed. Likewise, the use of dual-cured resins to place posts results in a flawed study since complete conversion requires light activation, and light will not penetrate to the depth of a post space. 

Therefore, a clinician is left to decide on how to restore an endodontically treated tooth based on observable “facts” within their own practices. Those observations over decades with teeth they have restored and followed will lead the clinician to prudent management. I have been fortunate to have observed these “facts” for more than 5 decades. My first lecture was in 1972 to our local dental society on how to fabricate and place a gold post. Since that time, I have restored thousands of endodontically treated teeth out of the more than 65,000 units I have placed and have been fortunate to practice in the same community for more than 50 years. I have followed the outcome of what I did for my patients on the majority of those 65,000 units. As materials and my experience evolved, so did my clinical protocols on how best to restore endodontically treated teeth. 

Here are the thoughts I have on restoring endodontically treated teeth today in the 21st century based on my clinical experience for more than 5 decades and a belief in shards of uncompromised dental literature: 

1. Properly restored teeth are better than implants. Implants are considered the route of last resort in our office. Well-done endodontic treatment, coupled with appropriate restorative procedures, can preserve teeth for decades. 

2. Posts should not be placed when there is no need since the placement of a post weakens teeth and is fraught with complications both from the endo-
dontic fill and biomechanical perspectives.

3. Active screw posts should never be used because they split teeth. 

4. Acid-soluble cements should never be used to place posts. The function of the cement is to retain the post. Acid-base cements are too weak to do that.

5. Glass ionomer cemented posts do not resist the formation of decay along the post space. 

6. The need for a post is not to retain the core but rather to prevent horizontal fracture of the core buildup. There is no other need for a post.

7. Posts are not indicated for teeth that are not planned for full-coverage restorations.

8. Posterior endodontically treated teeth require cusp-coverage restorations. Simple direct composites as definitive restorations are inadequate for the long-term success of endodontically treated teeth. 

9. Metal posts resist fracture of the core better than plastic or ceramic ones, which are prone to fracture.

10. Post spaces should never be initially prepared with end-cutting drills. Root perforation is common when this is done. Initial prep to depth (anything less than 10.0 mm is almost worthless) should be done with Peeso reamers or Gates Glidden drills, followed by sizing the post space with the end-cutting drill.

11. Post spaces can only be properly rinsed and dried with a Stropko Irrigator (Stropko). Paper point drying a canal to evaporate alcohol or acetone in primers simply will not take the substrate to the hydrophobic level necessary for successful bonding.

12. Teeth with core buildups that have adequate dimensions to resist fracture do not need posts. Molar teeth with posts result in many catastrophic failures. 

13. Core buildups should always be separate from the crown. Casting, pressing, or milling the core as part of the crown is a significant compromise.

14. The primary cause of failure on teeth restored with posts is root fracture, which is secondary to the cement’s failure to retain the post. Once the post is loose, any occlusal force will likely stress the fragile root enough to fracture it.

15. The secondary cause of failure on teeth restored with posts is coronal microleakage down the post space, resulting in failure of the endodontic fill.

16. Endodontically treated teeth become brittle over time and, additionally, are usually biomechanically compromised. Appropriate distribution of occlusal forces on endodontically treated and restored teeth is critical for long-term success.

17. Posts should be embedded in the core buildup as much as possible since the opacity of the buildup will block the appearance of the metal post, and if it is centered in the buildup, it will increase the fracture resistance of the buildup.

18. Titanium posts do not rust like stainless steel. Rust compromises cosmetics. Flexure of the core buildup causes fracture of the buildup and, frequently, the roots. Plastic posts flex and often break because they do not resist fracture of the core buildup. Ceramic posts do not flex but fracture easily.  

19. Titanium ParaPosts XP (Coltene) smaller than 4.5 are flexible and should be used with caution. Titanium alloy is more flexible than stainless steel, but that flexibility is clinically insignificant. 

20. Only chemically activated composite cement should be used to cement posts. Dual-cure cement requires light to fully cure, and light will not penetrate to the base of the post space where a complete cure is mandatory.

21. Molars almost never need posts since the volume of core material will not need to be reinforced to prevent fracture.

22. Bicuspids rarely need posts unless they are fractured off at the tissue level.

23. Most posts “succeed” because there was never a need to place one initially. This is one of the confusing aspects of retrospective studies on posts. 

24. There are cases where heroics can keep a tooth for quite some time, but when the volume of tooth structure is severely compromised, the prognosis is poor, and the outcome eventually will be failure.

25. It is prudent to attempt heroics when the age of the patient is factored into the treatment plan. Elderly patients may well benefit from a decade or so of service out of a heroic attempt to keep a tooth. Likewise, younger patients may benefit from keeping a tooth for a decade or so as the knowledge and prognosis of implant management grows at an exponential rate. Who knows, but what stem cell may grow a new tooth in the next decade or so? 

26. Placing a post or core buildup requires a precise protocol to ensure decades of success. Protocols that we use for core buildups and post placement are free to download at our website,
struppbrummseminars.com. Click on “Protocol Downloads” to access them. These protocols are bulletproof, if followed precisely. In addition, our products list is also free to download. It contains all the products we use and a contact source to get them. 

Two cases are presented here with captions to explain what was done. In addition, other photos are included to expand on certain aspects that require clarification. If you have any questions about this article, we will be happy to answer them on our Facebook page, Strupp/Brumm Dental Protocols, where more than 16,000 of the best dentists in the world gather to learn. 

CASE REPORTS

Case 1: Teeth Nos. 6 to 11 necessitated replacement. These restorations were made with porcelain butt joints in the cosmetic zone and placed with zinc phosphate cement. Posts were placed with Fuji Glass Ionomer Cement (GC) in Nos. 7, 8, and 10 (Figure 1).

Figure 1. Recurrent decay around and under 30-year-old porcelain-fused-to-gold restorations.

Case 2: Black discoloration along the labial porcelain butt joints was clinical evidence of decay. A 0.2 to 1.0 mm of recession over 30 years, coupled with the black discoloration along the margins, created a “cosmetic need” for the patient. The degree of pathology under the restorations was not clinically evident. Most restorations cemented with acid-soluble cement should be replaced after 2 to 3 decades, even if they “look” good (Figure 2).

Figure 2. Black discoloration along the labial porcelain butt joints.

After removing the old restorations, a significant amount of tooth structure was decayed because of the leaking restorations and dissolution of the acid-soluble cement. This was made worse by the patient’s habit of drinking acidic beverages. There was no bleeding tissue because a soft-tissue scrub with Pure 4% CHG (Best Buy Discount Dental Supply) was done 2 days before the preparations (Figure 3).

Figure 3. After removing the old restorations.

Case 3: Extensive loss of tooth volume occurred as the diseased tooth structure was removed. The glass ionomer cemented posts were removed using a sonic scaler. This exposed extensive decay along the post space walls, especially in the post space of No. 8. Because the projected volume of core buildup in No. 8 would satisfactorily resist horizontal fracture, a post was not indicated. Posts were indicated to resist horizontal fracture of the core buildups in Nos. 7 and 10, however, because the projected thin dimension of the core buildups were at risk for horizontal fracture without them (Figure 4).

Figure 4. Extensive loss of tooth volume.

Case 4: Our post placement protocol is the most critical protocol we use in advanced restorative cases, and the substrate to which we will bond must not be compromised. OpalDam Green (Ultradent Products) was used to cover the substrates and post spaces in Nos. 7 and 10 to prevent the products used in the core buildup protocol for Nos. 6, 8, 9, and 10 from touching the substrates and post spaces (Figure 5). 

Figure 5. OpalDam Green (Ultradent Products) was used to cover the substrates and post spaces.

Case 5: Core buildups were done for Nos. 6, 8, 9, and 11. Excessive buildup material was placed to allow preparation of an ideal shape and form and to cover as many open tubules as possible in the vital teeth. Properly done core buildups on vital teeth are like immediate dentin sealing on steroids (Figure 6).

Figure 6. Core buildups were done for Nos. 6, 8, 9, and 11.

Case 6: Using the Strupp/Brumm protocol, 4.5 Titanium ParaPost XP (Coltene) posts were placed with the chemical cure cement PANAVIA 21 (Kuraray). The core buildups were placed simultaneously with post cementation so that both composites would set together. There is a dot after the 4 and before the T on the post. This indicates a size 4.5 and that the post is titanium alloy (Figure 7).

Figure 7. Titanium ParaPost XP (Coltene) posts.

Case 7: Definitive preparations were done. We avoid touching the tissue as much as possible while creating an ideal shape and form to the abutments, which will accept the final lithium disilicate restorations. A single Sil-Trax Epi #00 retraction cord (Pascal) was soaked in Retrax AC (Pascal), blotted, placed, and immediately rinsed after placement on each tooth. Highly acidic hemostatic agents (which all hemostatic agents are) must immediately be rinsed to avoid severe damage to the abutments and necrosis of the tissue. Postoperative sensitivity usually results if these agents are not thoroughly rinsed immediately after use (Figure 8).

Figure 8. Definitive preparations were done.

Case 8: The ideal shape to make a perfect chamfer margin is the Diamond Bur #6877K/014 (Brasseler), which has a 55° elliptical radius. The same shape in the Polaris Diamond is #G-62 (Figure 9).

Figure 9. Brasseler and Polaris Diamond Burs.

Case 9: A definitive impression using Imprint 4 VPS (3M) was made that recorded unprepared tooth structure apical to the margin along with the entirety of the preps. We believe all margins recorded in an impression must include sound tooth structure apical to them to ensure a perfect fit of the final restoration (Figure 10).

Figure 10. A definitive impression using Imprint 4 VPS (3M).

Case 10: The cast from the first pour of the impression is used for dies. A second pour cast is made but not sawed. The second pour cast is used for checking proximal contacts on the final restorations after the soft-tissue zones are trimmed away from the margins to ensure a definitive seat of the final restorations (Figure 11).

Figure 11. The cast from the first pour of the impression was used for dies.

Case 11: Provisional restorations that fit perfectly and are cemented with Durelon (3M) are critical for tissue health on the day of final cementation. Patients are seen one week post-op to ensure all provisional cement is removed and the patient is doing appropriate home care and for a scrub with Pure 4% CHG (Best Buy Discount Dental Supply). Controlling the microbiome during the provisional phase is critical for long-term success. Cementing into a pool of blood produces certain failure, and is a disservice to the patient (Figure 12).

Figure 12. Provisional restorations that fit perfectly and were cemented with Durelon (3M).

Case 12: Durelon sticks to the teeth when the provisionals are removed. Its antimicrobial character keeps vital pulps vital and calm and minimizes the issue of cement sepsis (microbial growth under a restoration). Durelon is easily removed with a SONICflex (KaVo), which leaves black marks on the buildups. Painless anesthesia is always used for definitive cementation because we never want to hurt a patient during the placement process. Without anesthesia, the patient will never refer their friends because we hurt them (Figure 13).

Figure 13. Durelon sticks to teeth when provisionals are removed.

Case 13: Air abrasion with CoJet Sand (3M) removes all of the black marks and residual Durelon. Air abrasion can open a capillary, but that is usually very easy to control by scrubbing the open capillary with Retrax AC, which must be thoroughly rinsed away to avoid compromising the resin cement and substrate to which we will bond (Figure 14).

Figure 14. Air abrasion with CoJet Sand (3M).

Case 14: The cosmetic outcome is approved by the patient before definitive placement. Tissue health is mandatory for placement. A Pure 4% CHG scrub 2 days before placement minimizes bleeding, which is caused by a dysbiotic microbiome that invariably forms around margins on provisional restorations near the tissue. The second pour solid cast with the tissue trimmed away is used to confirm perfect interproximal contacts in the laboratory. Adjusting contacts clinically is a time suck and invariably results in loss of patient confidence (Figure 15).

Figure 15. The cosmetic outcome was approved by the patient.

Case 15: All of our patients are taught preventive dentistry techniques, and any bleeding tissue is scrubbed with Pure 4% CHG on a weekly basis until there is no bleeding due to aggressive brushing. This patient received preventive dentistry instructions, 3 scrubs with Pure 4% CHG, and a prophy. The microbiome present at the end of this protocol was symbiotic, and there was no bleeding tissue. The success of any clinical protocol depends on soft-tissue health before, during, and after the using the protocol. Posts or core buildups cannot successfully be done in a sea of blood, nor can cementation be successful in such conditions (Figure 16).

Figure 16. Results using Pure 4% CHG (Best Buy Discount Dental Supply).

Case 16: The photos before core buildups/post placement and after crown placement were remarkable and were given to the patient. The anterior envelope of function was designed in the laboratory with the weak teeth in mind, and occlusal loading was placed where it could best be sustained by the available biology. Communication with the laboratory and precise placement protocols are critical in cases with weakened biology. The bonding protocols used for post placement and core buildups will make or break a case of this complexity, but they are meaningless unless the occlusal forces are properly distributed (Figure 17).

Figure 17. Patient before and after photos.

Case 17: When does the implant become the treatment of choice? Should heroic dentistry be done? Every dentist must make this decision and live with the consequences. If a patient says he or she wants to keep the tooth, when do we say no? This patient was in his 80s, and the fee was no object. He just wanted to keep the tooth. I explained the poor prognosis and proceeded to accommodate his wishes (Figure 18).

Figure 18. Preoperative image of an 88-year-old patient.

This case will combine many of the issues and treatments discussed here so far. An 88-year-old patient had been keeping a loose post/core/crown in place with denture adhesive for over a year. His dentist was OK with that. He was also OK with the obvious failing dentistry. Go figure? Before I understood proper bonding protocols for core buildups on these vital teeth, I was afraid the core buildup would come out when I removed the provisional. This is an unwarranted fear today because our buildup protocol is bulletproof. 

Only a shell of a tooth was left, and decay extended close to the crest of the bone. Removing bone to accommodate a ferrule or to gain crown length to avoid the issue of violation of the biologic width would compromise the bone needed for an implant when one would most certainly need to be done at some point in time for this case. A closed-flap biologic shaping protocol was used instead to allow fabrication of a final restoration with an equigingival margin (Figures 19 and 20).

Figure 19. Extract, implant, or restore?

Figure 20. Hopeless?

A post was placed to resist fracture of the core buildup in No. 10, and closed-flap biologic shaping was accomplished with the plan to marginate at the crest of the tissue on core paste after healing. The core buildup on No. 10 was in violation of the biologic width, but it was reshaped along with tooth structure apical to it, then both the prepared root surface and core buildup were highly polished. Core buildups were d one on the vital teeth Nos. 7 to 9. The provisional was made on No. 10 with margins well coronal to the tissue level to allow proper healing. See Figure 21 for what it looked like 1 month later. 

Figure 21. CFBF and 1 month later.

He returned 7 months later for re-evaluation. The objective of closed flap biologic shaping is to create an interface between the soft tissue and the core buildup, which was placed in violation of the biologic width in a perfectly dry environment, that can be maintained with good home care and Pure 4% CHG scrubs every 3 months. There is no “attachment” of the soft tissue to the core buildup; rather, there is a hemidesmosomal approximation of the soft tissue to the core buildup, much like what exists with implants. The post will resist fracture of the core buildup and is hidden by it, so metal is not a cosmetic issue when the post is properly contained within the core buildup. Ceramic or resin posts are woefully inferior in resisting fracture of the core buildup on thin teeth. The patient was away for 7 months before we had a chance to finalize the case. Well-made provisionals will enhance healing (Figures 22 to 24).

Figure 22. CFBF and 7 months later.

Figure 23. Preparations.

Figure 24. Seven months post closed-flap biologic shaping.

Here is how the case resolved at 2.5 years after placement. The final monolithic Lisi Press (GC) case with equigingival margins placed on the core buildup on No. 10 resulted in perfect tissue health. Clearly, this case is destined to fail if the patient bites into little more than a potato chip, but he has been very careful not to abuse the severely compromised biomechanical situation. Without proper protocols for placement of the post and core buildup and appropriate distribution of occlusal forces, this case would have failed within weeks (Figure 25).

Figure 25. Photo 2.5 years after placement.

We should mention here that all of our cases, which are either HP 77 gold (Argen) or Lisi Press, are bonded in with PANAVIA F 2.0 (Kuraray). It is the only cement we have used this century to place our restorations (more than 25,000 units). 

CONCLUSION

Some final words about our post and core preparation protocol. Correct positioning of a post can be accomplished using a prep shim with a hole drilled just lingual to the incisal edge for the post to exit coronally so it is positioned exactly where is should be to both support the buildup in resisting fracture and be hidden by the core buildup. This keeps the post from being visible. There is simply no need for a “cosmetically” colored post that is too weak to resist fracture (Figure 26). The sequence is critical. The post is placed using our PANAVIA 21 cement protocol, Core Paste XP Enamel (DenMat) is used to displace as much of the cement as possible, the prep shim is seated to guide the post into the correct position before the snap set of Panavia 21 occurs, and the rest of the core buildup is “injection molded” through the hole in the prep shim (Figure 27). The posts then must be properly covered. The prep shim properly positions the posts to aid in resisting horizontal fracture of the core buildup (Figure 28). As a result of following this sequence, no metal shows. The opacity of Core Paste XP Enamel blocks metal easily. Margination subgingivally is necessitated by the discolored roots secondary to long-standing root canals (Figure 29).

Figure 26. Prep shim with hole drilled just lingual to the incisal edge.

Figure 27. The sequence is important.

Figure 28. Posts properly covered.

Figure 29. No metal shows.

We hope we have brought you along on this 50-plus-year journey helping patients with more than 65,000 units and given you all new ways to look at your patients and give them the best possible care.

ABOUT THE AUTHORS

Dr. Strupp was the inaugural speaker at the American Academy of Cosmetic Dentistry (AACD) founding meeting in 1984. He is an Accredited Fellow in the AACD. Fellowship, a select group of fewer than 100 people worldwide, is the highest level of achievement recognized by the AACD. The status of Accredited Fellow of the AACD is granted only after completion of all requirements. He is or has been a member of virtually every meaningful academy in dentistry. Dentistry Today has selected Dr. Strupp as a Leader in Continuing Education in dentistry every year the leaders have been recognized. He has lectured to more than 45,000 dentists and is considered to be at the top of the most elite group of teachers in dentistry. Elite clinical results are routine for the many complex cosmetic and restorative cases he has completed since entering private practice in 1969. He can be reached at bill@strupp.com. 

Dr. Brumm received his DMD degree from the University of Louisville in 2006. He is an Accredited Fellow Member of the American Academy of Cosmetic Dentistry. He is also former president of the Florida Academy of Cosmetic Dentistry. Dr. Brumm is a certified dental technician. The CDT designation is a great achievement and demonstrates a significant mastery of the knowledge and applied skills needed in dental technology. Dr. Brumm has also lectured nationally and internationally to dentistry professionals on the subject of simplifying complex cosmetic and restorative dentistry. He can be reached at mike@strupp.com.

Disclosure: Drs. Strupp and Brumm manufacture and sell Pure 4% CHG. 

Meet Carson. He lost tooth No. 9 at the tender age of 14 after a battle to resolve its developmental impaction (Figure 1) and reoccurring infections (Figures 2 to 5). He had multiple failed Maryland bridges (Figure 6), and his current dentist had told him there was nothing further they could do to help him. Carson’s orthodontist, who had been overseeing the case for 6 years, referred the family to me. When Mom called to schedule the initial visit, she said, “Our dentist has fired us, and we have no one to turn to.”  

Figure 1. Panoramic x-ray showing the developmental impac- tion of tooth No. 9.

Figure 2.

Figures 2 and 3. Exposing and bonding and bringing tooth No. 9 into position were somewhat successful, but reoccurring infections at No. 9 could not be resolved.

Figure 4.

Figures 4 and 5. Even after extraction, it still took time and additional procedures by the oral surgeon to clear the infection. The loss of the tooth was catastrophic but necessary.

INITIAL PERSONAL THOUGHTS

When I met Carson, he was 16 years old and wearing an Invisalign tray (Align Technology) with missing tooth No. 9 painted in White Out. It was really heartbreaking and something I had never encountered. His self-esteem was circling the drain, and his parents were terrified these circumstances would permanently scar him. He was sullen, moody, and would barely look at me. He wore a hoodie with the hood pulled up at all of his visits with me. He couldn’t bring himself to smile for clinical photos—he honestly did not know how (Figures 7 and 8). The vivacious, confident, smart young man that his parents had raised was vanishing before their eyes. His orthodontist saw what was happening and stepped in to help by sending Carson to me. 

Figure 6. One of the Maryland bridges before it failed. The family and patient had been a little underwhelmed by the aesthetics of this Maryland bridge.

Figure 7.

Figures 7 and 8. Carson couldn’t even smile for clinical photos—he honestly did not know how. This was the best smile we could coax out of him.

DEVELOPING A PLAN

An ideal scenario when a patient is missing a tooth is the placement of a dental implant. Not only was Carson too young for this option but the space available for an implant was also too narrow both bucco-lingually, due to the destruction of the bone by the recurrent infections, and mesiodistally, as confirmed by the oral surgeon who extracted the tooth after multiple attempts to bring it into position by the orthodontist (Figures 9 and 10). The lack of adequate space for an implant was also confirmed via a CBCT scan. The orthodontist did not feel that putting any more orthodontic forces on the already compromised tooth No. 10 was a good option, especially considering the abbreviated root structure and its proximity to the site of recurrent infections. This was confirmed in the radiograph (Figure 11). Carson had already been through 6 years of orthodontics, both early/interventional and conventional, with a few pauses periodically while the endodontist and oral surgeon treated the recurrent infections at No. 9. 

Figure 9.

Figures 9 and 10. Final orthodontic space for No. 9 and the continuing battle to resolve the infection.

After spending considerable time studying Carson’s case with an experienced and highly skilled ceramist, we feared that a new Maryland bridge was not a viable option. The factors affecting his candidacy for a Maryland bridge included the large width of the space available; the tilt and shape of the surrounding teeth; and the thick gingival tissue on the facial of the site where tooth No. 9 was missing, which would have required a very long wing (Figure 12). These factors may have contributed to the failure of 2 previous Maryland bridges and Carson being “fired” by the previous dentist. (The family was never pleased with the aesthetics of the old Maryland bridge, either [Figure 6].)

While not the most ideal, we did still have options for Carson. The parents, the orthodontist, and I began discussing crown and bridge. The downside of this option was the removal of mostly healthy tooth structure on the abutment teeth—particularly in such a young patient—for no other reason than to replace missing tooth No. 9. However, the advantage was that this option had the potential to be the most aesthetic of all available options, and it would certainly be much more stable with a better prognosis than a Maryland bridge. Carson was also at high caries risk; note the incipient interproximal lesions on the anterior teeth (Figure 11). Further, he had 2 mm of overjet, meaning that the lingual surfaces of his maxillary anterior teeth would not even need to be prepared, and the bridge would be exempt from normal occlusal forces. 

Figure 11. Inadequate space for an implant for No. 9. Note the abbreviated root structure and tipping of tooth No. 10.

Figure 12. Note the thick facial tissue where No. 9 was missing, which made this site less favorable for a Maryland bridge.

Finally, it is very helpful to have an option that has fallbacks or safety nets, ie, if plan A fails, we still have a plan B. Most of the time, extracting teeth and placing implants is the final plan—if an implant fails, there aren’t usually many alternatives to that treatment option other than hoping the implant failure did not destroy bone in such a manner that would prevent an additional redo attempt at implant therapy. So while implant therapy is often the ideal solution for missing teeth, looking at cases like these, we look for a restorative plan that may work for some period of time before resorting to implants. Attempting to use the existing natural teeth first, even if they aren’t perfect, rather than just extracting them and going straight to an implant plan is often the best solution. It is often surprising how many years an alternative restorative plan can “buy” the patient prior to extractions and implant placement. 

In Carson’s situation, tooth No. 10 was already compromised, and the case was made that if we continued orthodontic treatment, we risked losing that tooth as well and continuing to damage Carson’s self-esteem in the process. I told the family if we could stop ortho after 6 years of orthodontics and get an immediately excellent aesthetic result for Carson, what’s the worst that could happen—the failure of a bridge abutment? It seems (optimistically) unlikely, considering the entire maxillary anterior was not in occlusion, but if we did lose one of the bridge abutments (tooth No. 8 or 10) all of a sudden, we would have room for an implant that could serve as a cantilever bridge option. This would be our “plan B” if plan A failed. So we started talking about a conventional bridge from Nos. 8 to 10 with a porcelain veneer for No. 7 to make it symmetrical, treating as few teeth as possible. I witnessed the family’s growing excitement about trying something different for Carson. 

PRESENTING THE PLAN TO PATIENT AND FAMILY

In the interest of thoroughness, which I believe all patients deserve, here are the options I gave the family. 

Option 1: Placement of a crown on compromised tooth No. 10 with a pontic cantilevered off it to replace No. 9. The upside of this option was that it would be much more stable than a Maryland bridge. The downsides of this option included: 

1. The removal of otherwise perfectly healthy tooth structure of No. 10 for no other reason but to replace No. 9 

2. It is challenging to achieve ideal aesthetics by treating only 2 teeth on one side of the smile/midline

3. The limited ability to improve the aesthetics of tooth No. 8 

4. The possibility to further compromise the already compromised tooth No. 10 

One potential saving grace of this option was that we would be removing tooth structure from a tooth, No. 10, which was already compromised and had a questionable long-term prognosis. If tooth No. 10 were to break, then it would probably need to be extracted, in which case we would benefit because now we would have sufficient room for an implant. 

Option 2: Placement of a conventional bridge from teeth Nos. 8 to 10 with a pontic on No. 9. I explained that in cosmetic dentistry, we always at least consider and discuss with the patient treating teeth symmetrically in the smile/on both sides of the midline for the best aesthetic outcome. For this reason, I also recommended a porcelain veneer for tooth No. 7. Downsides of this option included: 

1. The removal of otherwise perfectly healthy tooth structure from teeth Nos. 7, 8, and 10 for no other reason but to replace missing tooth No. 9 

2. The possibility to further compromise the already compromised tooth No. 10 (though far less compromise with this option than with option 1 since tooth No. 8 would also assist in supporting the pontic for No. 9)

The upsides of this option included:

1. Better prognosis than option 1 since tooth No. 8 would aid compromised tooth No. 10 in supporting missing tooth No. 9

2. This option would provide the best aesthetic outcome

3. With this option, we would have better control over the shape and aesthetics of No. 8

The family was told that if they were interested in this option, our next steps would be to work with my ceramist to complete a diagnostic wax-up to plan the case. Once that step was completed, we would be ready to start. We would prepare the teeth for the restorations and place temporary restorations, which would be indicative of the final result (based on the diagnostic wax-up). Carson would wear these temporary restorations for approximately 6 weeks while the laboratory fabricated the final porcelain restorations. This would give him time to ensure he was pleased with the anticipated final result. The family was advised that the final restorations might have to be returned to the lab for modifications if the shade match was not ideal. In this case, the temporaries would be worn longer than 6 weeks. Once the final restorations were in place, it would also be necessary to make new retainers. 

The family was told that this was quite a bit more involved than we had previously discussed (certainly more involved than a Maryland bridge); however, I did not want Carson to continue suffering the consequences of failure of a front tooth any longer at such a critical social and physical developmental time in his life. The previous experience with a Maryland bridge was hard on Carson and the family, and we didn’t want to repeat that experience for him. Again, it was reinforced that this should be more successful than the Maryland bridges that had already failed for Carson. This was a critical time in Carson’s formative years, and I felt he deserved the option of a stable, good-looking smile he could feel confident in.

To be sure all of the options were understood, we did discuss the option of making a removable acrylic partial (flipper). They had no interest in considering this option (and in all honesty, neither did I). 

IMPLEMENTING THE PLAN

Ultimately, the family chose the conventional 3-unit bridge from teeth Nos. 8 to 10 and a porcelain veneer for tooth No. 7 for the best symmetry. We whitened Carson’s teeth first using the Zoom! in-office whitening system (Philips Oral Healthcare). We completed the diagnostic wax-up via typical analog PVS impressions and stone models with Treasure Dental Laboratory in Idaho Falls, Idaho. Once the diagnostic wax-up was completed, No. 7 was prepared for a conservative porcelain veneer, and teeth Nos. 8 and 10 were prepared for an all-porcelain bridge using a clear suck-down matrix of the wax-up to ensure prep design supported the planned restorations. Lithium disilicate (IPS e.max [Ivoclar]) porcelain restorations for the case were planned, and the case was temporized using the spot-etch and bond/shrink-wrap technique using a putty matrix of the diagnostic wax-up. (Products used for the temporary restorations included Prime&Bond elect Universal Dental Adhesive [Dentsply Sirona] and Integrity monomethacrylate/polymethacrylate provisional material [Dentsply Sirona] in bleach shade). The challenging part aesthetically was addressing the tipping of tooth No. 10. The contours on the distal of the bridge were not ideal but were the best we felt we could achieve based on the natural tooth position present underneath the bridge. Treasure Dental Laboratory did an amazing job on this case. 

Prior to and during treatment, it was noted that Carson’s muscles for smiling (oribicularis oris, risorious, LLSAN, etc) appeared to be somewhat atrophied. We could barely move the lips out of the way to take photos of the preps for the laboratory and when finishing the provisionals. This is the explanation for the less-than-ideal photos seen here of the preps. Note how conservative these preps were, especially theminimally prepared lingual surfaces. There is just a finish line at the gingival aspect of the lingual surfaces and smoothed lingual surfaces to blend them into the preparations. There was no need for substantial lingual preparation because of the patient’s overjet (Figures 13 and 14.)

Figure 13.

Figures 13 and 14. Conventional bridge preps for IPS e.max (Ivoclar) teeth Nos. 8 and 10 and IPS e.max porcelain veneer prep No. 7; the lingual surfaces of Nos. 8 and 10 were minimally prepared since the patient had overjet.

The transformation was immediate. When Carson came in for us to check the provisionals, the hoodie was still there, but you can see in the photos his attempts to smile for the first time in many years (Figure 15). This was definitely the first time we had ever seen even an attempt at a smile from Carson. 

Figure 15. Carson wearing his provisionals and still wearing his hoodie but obvi- ously attempting to smile.

Figure 16.

Figure 17.

Figures 16 to 18. Final IPS e.max restorations: porcelain veneer for tooth No. 7 and a 3-unit bridge for Nos. 8 to 10. Gone is the hoodie, and already Carson is building his atrophied smile muscles.

The completed IPS e.max restorations are seen in Figures 16 to 18. It is notable that the hoodie is gone, and the smile muscles are only growing stronger. In person, he was bubbly to the point of being excited. My reward was the fact that he hugged me instead of barely looking at me and giving me one-word answers. And he told me he had even asked a girl to his upcoming homecoming dance.

FINAL COMMENTS

Was this the hardest case technically? No. Was it super sophisticated? No. Was it the most aesthetic case you’ve ever seen in your professional life? No. Will some dentists comment about doing a 3-unit anterior bridge for a 16-year-old? Yes! But did the treatment provided substantially change a person’s life? Yes! Did seeing his life change for the better change my life for the better? One thousand times, yes! 

It is hard sometimes to keep going strong after 20 years at it. Dentistry is hard on many days. Cases like these are what keep me going. I hope you enjoyed reading about it. I encourage us all to “think outside the box” when the Carsons of the world land in our offices—no one wants to do a 3-unit bridge and a veneer in a 16-year-old. But I do believe this was the right answer in this case. I am certain Carson and his family agree. I hope you are inspired to think outside of the box should a Carson ever walk into your office!F  

ABOUT THE AUTHOR

Dr. Hoppe earned her BA in biology with a minor in chemistry from Texas A&M University and her DDS degree from the University of Texas Health Science Center in Houston. She was awarded the prestigious Fellowship in the AGD in 2012. Dr. Hoppe owned and operated a small dental practice in Austin, Texas, for 10 years. Upon relocation to Florida, Dr. Hoppe stepped into the role of dental director for the Children’s Volunteer Health Network, treating more than 1,000 children and providing more than $300,000 in free dental care for underprivileged children in Walton and Okaloosa Counties. She simultaneously opened her state-of-the-art comprehensive care dental office, 30A Smiles, which she co-owns in the Inlet Beach area. She can be reached via her Instagram handle, @drlindseyhoppe, or at her website, 30asmiles.com.

Disclosure: Dr. Hoppe reports no disclosures.

INTRODUCTION

It’s all over the news: Dentists are treating more cracked teeth since the onset of the COVID-19 pandemic—sometimes at twice the typical rate.¹ The vast majority of dentists indicate that the prevalence of stress-related oral health conditions among their respective patients has increased since the beginning of the COVID-19 pandemic, according to the ADA Health Policy Institute’s latest data from its COVID-19 economic-impact tracking poll conducted the week of February 15.² More than 70% of dentists surveyed saw an increase of patients experiencing teeth grinding and clenching, conditions often associated with stress—up from just under 60% in the fall. Dentists also reported increases in chipped teeth (63%); cracked teeth (63%); and temporomandibular joint disorder symptoms (62%), which includes headaches and jaw pain.²

Pandemic stress, quarantine fatigue, mask burnout, online overload—whatever you want to call it, it’s added stress that people across the globe are experiencing. Stress comes out in many different ways, and each person responds differently, but there is definitely a trend of stress-related issues in dentistry. Management of this stress is a primary concern. Whether you practice mindfulness, begin a yoga habit, or seek professional medical help, addressing the feelings you’re having now is as important as treating the symptoms they are causing.³ The key to any successful treatment plan is understanding the cause of the current condition. This allows you to arrive at the correct diagnosis and develop a treatment plan that will have a predictable, long-term, successful outcome. So, on the surface, the treatment of a cracked tooth may seem simple: Restore the crack with a crown or another appropriate restoration, and that is it. However, if the underlying cause has not been addressed, your treatment is susceptible to failure.⁴ 

Cracked teeth and the various complications that arise with this particular type of case can be one of the most significant challenges facing the preventive, restorative dentist today. They present a clinical challenge due to their complex diagnosis and unpredictable prognosis. Treatment often varies depending on the nature of the crack and the clinical experience of the operator. Cracked teeth are challenging to diagnose clinically because of the complicated and diverse symptoms associated with this condition and the challenge in locating crack lines. There is no consensus among dental practitioners regarding the best approach to treat cracked teeth. But what we do know is the treatment and outcome for a cracked or fractured tooth is dependent on the location, direction, type, and size of the crack.^5,6 Being able to distinguish these differences can aid in a diagnosis that will ultimately lead to proper care and treatment. The American Association of Endodontists has classified 5 types of cracks in teeth⁷: 

1. Craze lines 
2. Fractured cusp 
3. Cracked tooth 
4. Split tooth 
5. Vertical fracture

These 5 categories of dental fractures have been devised to provide global definitions that researchers and clinicians can use to decrease this confusion. Combining this knowledge with a proper dental history, clinical examination, and radiographic assessment, as well as a periodontal and occlusal evaluation, can help one determine the proper course of treatment for a particular case.⁸

The following case presentation will highlight the treatment of an incomplete fracture of an upper second premolar. Though there were many ways to approach the treatment of this particular case, the modality chosen focused on a minimally invasive approach involving immediate dentin seal and its emphasis on crack repair.⁹

CASE REPORT

A 60-year-old male patient in good physical health with no underlying medical complications presented complaining of discomfort when biting on his upper left side for approximately the previous 10 days. A radiograph, as well as a visual examination, was conducted, along with a periodontal and endodontic evaluation. It was determined rather quickly that the upper right second premolar was the culprit. Utilizing a transillumination device (AdDent), the large fracture running mesial to distal was easily visualized (Figure 1). Radiographically, there was no sign of pathology, and all vitality testing came back within normal limits. Periodontally, the same can be said regarding the lack of significant findings, as all probe readings were in the normal range of 2 to 3 mm. Treatment options, and the understanding of the complexities of treating a fractured tooth like this, were discussed with the patient. He understood that there was no guarantee that this tooth could be saved with 100% predictability. An integral part of dealing with cracked teeth is that the patient fully understands the situation and has total buy-in when deciding on the course of treatment. 

The area was then anesthetized (4% articaine, 1:100,000 epinephrine [Septodont]). Isolation was achieved utilizing a DryShield evacuation system to help achieve an optimal working environment. Being a virgin tooth, the fractured premolar was then explored by utilizing a pear-shaped diamond bur (Meisinger) to begin to evaluate the depth of the fracture. Approaching this fundamentally, the design principles involved in minimally invasive dentistry, combined with a biomimetic approach, helped me establish a protocol when chasing a fracture. The ideal goal was to chase the fracture to a depth of 5 mm from the occlusal surface and a depth of 3 mm interproximally from the axial wall.¹⁰ I tried to be careful not to remove too much of the cracked dentin and cause a pupal exposure. The preparation felt complete after I flattened out both the buccal and lingual cusps utilizing an 856 diamond bur (Meisinger) to create a cusp clearance of approximately 1.5 mm. I utilized a large enamel band to help take this preparation from a predominantly tensile position to one of compression, enabling the support to be transferred away from the remaining fractured dentin (Figure 2). Feeling comfortable with my preparation, a marginal elevation band (Garrison Dental Solutions) was placed and secured with 2 interproximal wedges (Palodent Plus System [Dentsply Sirona]) (Figure 3). The band is being utilized to help me raise the interproximal margins slightly supragingival, as well as support the bio base at the interproximal. The fracture was still partially in the dentin-enamel complex, and I was not comfortable chasing that fracture any further. With the band in place, CLEARFIL Universal Bond Quick (Kuraray) was applied to the tooth in an agitated fashion for roughly 10 seconds, then air thinned with a dedicated air line to help reduce contaminants, and then light cured for 20 seconds with an LED curing light (PinkWave [Vista Apex]) (Figure 4). CLEARFIL MAJESTY Flow (Kuraray) was then applied to the entire dentin-bonded surface at a depth of 0.5 mm in a horizontal fashion and light cured for 20 seconds. Some everX Flow (GC America) was applied directly over the fractured portion of the preparation at a depth of approximately 1 mm. This is a short fiber-reinforced flowable composite that increases the fracture toughness of the tooth and should prevent the existing dentin crack from propagating and causing failure (Figure 5).¹¹ The multidirectional fibers found in everX Flow helped bridge the crack and transferred the stresses to regions of greater structural integrity. Finally, a thin layer of CLEARFIL MAJESTY Flow was placed over the everX Flow to ensure a smooth transition and polymerized for the final time for 20 seconds. The band was removed, and the surface was polished with Enhance Finishing Cups (Dentsply Sirona) to remove any flash or possible discrepancies prior to taking our final scan (Figures 6 and 7). The temporary was cemented and the tooth was taken slightly out of occlusion in all excursions. Detailed instructions were given to the patient in regard to home care and management of that area while the permanent restoration was being fabricated.

Upon returning to the office, the patient was happy to report there were no signs of discomfort or anything to lead us to believe that we were on the wrong path to a successful outcome. The area was once again anesthetized (4% articaine, 1:100,000 epinephrine [Septodont]), and a DryShield Evacuation System was placed to help in the removal of the temporary and in the bonding protocol of our final restoration. After removal of the temporary, a large piece of Teflon tape was wrapped around the preparation to help protect the gingiva, and air abrasion was performed with the PrepStart H₂O (Zest Dental Solutions) utilizing 50-µm aluminum oxide to clean the immediate dentin seal-coated surface (Figure 8). The zirconia restoration (Argen) was then tried in and adjusted to our specific needs. It was then taken to the lab, where it was air abraded for 5 to 6 seconds with 27-µm aluminum oxide to ensure a clean intaglio surface was achieved (Figure 9). In order to bond zirconia restorations, it is critical one achieves an activated surface free of any contaminants that can hinder the chemical interaction. This can be achieved with the introduction of the phosphate monomer MDP.¹² The MDP monomer has a very strong affinity to phosphate, which is the predominant component in freshly cleaned zirconia. CLEARFIL CERAMIC PRIMER PLUS (Kuraray), the MDP-containing primer used in our case, was applied to the intaglio surface and allowed to dwell (Figure 10).

With the restoration now ready, the tooth was then prepared by placing 35% phosphoric acid in a total-etch technique for 20 seconds, and then it was rinsed and dried. CLEARFIL Universal Bond Quick (Kuraray) was placed on the tooth and scrubbed and agitated for 10 seconds prior to air thinning until a lack of bonding agent movement was seen along the preparation (Figure 11). PANAVIA SA Universal Cement (Kuraray) was placed directly on the uncured bonding agent, and the restoration was then seated (Figure 12).

One of the unique features and reasons as to why this cement combination was chosen was because of the built-in dual-cure formulation between CLEARFIL Universal Bond Quick and PANAVIA SA Universal. By not having to polymerize the bonding agent prior to cementation, this ensured that there would be no pooling anywhere along the preparation to create an insufficient seating of the restoration. The restoration was then tack-cured for 3 seconds, and excess cement was removed facially and lingually as well as interproximally with floss. After all excess cement was removed, the restoration was then light cured from all directions for 20 seconds. Enhance Finishing Cups were used to polish the facial and lingual surfaces before checking occlusion. A fine diamond (Meisinger) was used to adjust, and the final polish was completed with a 3-step intraoral zirconia-polishing system (Meisinger) (Figure 13). Postoperative instructions were discussed with the patient, and a final radiograph was taken to ensure complete seating of the restoration and integration with our prior marginal elevation (Figure 14).

CLOSING COMMENTS

The protocol for preventing and treating cracked teeth is advanced yet simplified. By choosing a treatment modality that replaces lost or damaged tooth structure with proper materials and maximum bond strengths while minimizing the stress, we can ultimately achieve a durable and maintainable restoration. Today’s materials provide all of that in reliable bonding technology and flexural strengths, allowing us to prepare non-geometric, retentive preparations that take advantage of the built-in physical properties of natural tooth structure while avoiding the ever-destructive 360° margin preparations. Using biomimetic restorative protocols and concepts increases the longevity of restorative dental treatments and reduces or eliminates future cycles of retreatment, a concept that both the dentist as well as the patient can enjoy every day. 

REFERENCES

1. American Dental Association. HPI poll: Dentists see increase in patients’ stress-related oral health conditions. September 28, 2020. 

2. American Dental Association. HPI poll: Dentists see increased prevalence of stress-related oral health conditions. March 2, 2021. 

3. Harvard Health Publishing. Best ways to manage stress. January 8, 2015. 

4. Mamoun JS, Napoletano D. Cracked tooth diagnosis and treatment: An alternative paradigm. Eur J Dent. 2015;9(2):293-303. doi:10.4103/1305-7456.156840

5. Lee JJ, Kwon JY, Chai H, et al. Fracture modes in human teeth. J Dent Res. 2009;88(3):224–8. doi: 10.1177/0022034508330055

6. Seo DG, Yi YA, Shin SJ, et al. Analysis of factors associated with cracked teeth. J Endod. 2012;38:288–92. doi:10.1016/j.joen.2011.11.017

7. American Association of Endodontists. Cracking the cracked tooth code: detection and treatment of various longitudinal tooth fractures. Summer 2008. 

8. Abou-Rass M. Crack lines: the precursors of tooth fractures-their diagnosis and treatment. Quintessence Int Dent Dig. 1983;14:437–47.

9. Magne P. Esthetic and Biomimetic Restorative Dentistry: Manual for Posterior Esthetic Restorations. University of Southern California School of Dentistry; 2006.

10. Alleman DS, Magne P. A systematic approach to deep caries removal end points: the peripheral seal concept in adhesive dentistry. Quintessence Int. 2012;43(3):197-208. 

11. Garoushi S, Sungur S, Boz Y, et al. Influence of short-fiber composite base on fracture behavior of direct and indirect restorations. Clin Oral Investig. 2021;25(7):4543-4552. doi:10.1007/s00784-020-03768-6

12. Blatz MB, Alvarez M, Sawyer K, et al. How to bond zirconia: the APC concept. Compend Contin Educ Dent. 2016;37(9):611-617; quiz 618. 

ABOUT THE AUTHOR

Dr. Schmedding graduated from the University of Puget Sound prior to getting his DDS degree at the University of the Pacific, Arthur A. Dugoni School of Dentistry. For 17 years, Dr. Schmedding practiced in Seattle prior to relocating to California. He held a position as an assistant professor in the Department of Integrated Reconstructive Dental Sciences at the University of the Pacific, Arthur A. Dugoni School of Dentistry. In addition to his pursuits in academia, Dr. Schmedding enjoys his private practice in Walnut Creek, Calif, and lectures nationally and internationally on topics ranging from advanced dental materials and products to complex restorative procedures. He has published articles both nationally and internationally regarding dental restorative materials and procedures. Dr. Schmedding is a current member of the ADA, the California Dental Association, and the American Academy of Cosmetic Dentistry. He is one of 450 dentists worldwide to be an accredited member of the American Academy of Cosmetics. He can be reached at troy.schmedding.dds@gmail.com. 

Disclosure: Dr. Schmedding received an honorarium from Kuraray Noritake for writing this article.  

Align Technology, Inc. (“Align”) (Nasdaq: ALGN) a leading global medical device company that designs, manufactures, and sells the Invisalign system of clear aligners, iTero intraoral scanners, and exocad CAD/CAM software for digital orthodontics and restorative dentistry, today announced the new iTero Workflow 2.0 software release with advanced features that provide enhanced intraoral image sharpness for clearer hard and soft tissue details to aid in treatment diagnosis, while also driving practice efficiency, patient engagement, and a more seamless end-to-end digital treatment experience for doctors and their patients.

“Align’s commitment to innovation in digital orthodontics and restorative dentistry reflects our $250 million annual investment in technology to develop products and services that provide doctors and their patients with a great treatment outcome and seamless experience through the Align digital platform,” said Yuval Shaked, Align SVP and MD of the iTero systems and services business. “Our new iTero Workflow 2.0 software features were developed to simplify and streamline a doctor’s daily routine and increase practice efficiency. From a faster, all-in-one scan with enhanced visualisation capabilities to improved patient communication, including the ability to capture, annotate and then share Invisalign simulations or restorative treatment plans digitally, these new features provide doctors with the ability for better clinical diagnosis and help patients better understand their oral health conditions and the proposed treatment options.”

The newly released iTero Workflow 2.0 software features include:

·               Faster scanning: Enables a faster and smoother all-in-one scan for maximum efficiency with 20% less waiting for processing time on the iTero Element Plus Series scanners1 and 50% faster movement and 25% faster rotation during scanning2 for efficient daily use and ease of learning on all iTero Element scanners. 

·               Improved visualisation: The integrated 3D intraoral camera included in the iTero Element 5D Plus imaging system provides enhanced sharpness and improved image quality powered by advanced AI capabilities to deliver clearer soft and hard tissue details to support diagnosis3. In addition, the enhanced capabilities allow clinics to efficiently use intraoral scan images in place of traditional intraoral photos as they can capture multiple intraoral images at different angles automatically with one scan.

·               Next level patient communication tools: The new Snapshot tool and iTero Scan Report provide doctors and their staff with the ability to capture information such as Invisalign Outcome Simulator projections and share it digitally with their patients, allowing patients to make more confident decisions – in the dental chair or at home – which may lead to higher treatment acceptance.

“I am already experiencing meaningful difference with the new iTero software features and have seen significantly reduced scan times,” said Dr. Olivier Boujenah, a dentist in France who participated in the limited market release. “The intraoral images are much sharper, and my patients are impressed by the details and clarity, which leads them to ask more questions about treatment options. Being able to send digital files with patients when they leave the office through the iTero Scan Report keeps our conversation going even after they are home, and I already see this capability helping with patient acceptance.”

iTero Workflow 2.0 software features are being rolled out regionally and are expected to be available in all markets where the iTero Element Plus imaging systems are available.  The iTero Element Plus Series is available in the United States, Canada, European Union, Norway, Switzerland, United Kingdom, Australia, New Zealand, Japan, Singapore, Hong Kong, and India with availability expected in other markets throughout 2021 and 2022. Software features will vary by scanner. Discover more at https://bit.ly/2ROw0fD.

 Simplified workflow through new iTero Element 5D auto-upload functionality

The company also announced the launch of a new iTero Element 5D imaging system auto-upload of intraoral photos for Invisalign case submissions. This new functionality eliminates steps and streamlines Invisalign case submissions with intraoral color scan images that can be used in place of traditional intraoral photos.

The iTero Element 5D imaging system wands are designed with advanced technology, including an intraoral camera, that enables the doctor to scan, capture and auto convert the scan into 2D color photos.   This enhanced capability provides doctors the option to automatically populate the five required images in the prescription form in the Invisalign Doctor Site (IDS) with 2D color scan photos. Currently, the Invisalign prescription form requires at least five intraoral photos upon submission, taken with Invisalign Photo Uploader (IPU) or a digital camera.   This new auto upload functionality will be available in all markets where the iTero Element 5D imaging systems are sold.

“The iTero Element 5D is a milestone in the development and modernisation of my practice” – said Dr. Joanna Vorhauser, Invisalign dentist from Germany. “The technology does not only impress our team, but also our patients and supports us in our communication with them: Now our patients can see their teeth and oral health from our perspective. The visualisation tools are also great for educational discussions and documentation. With the availability of the 5D auto upload functionality, we can now submit Invisalign case prescription without the need for intraoral photos, which makes the upload to the Invisalign Doctor Site is even faster. These improvements are also much more convenient for patients, and my assistant doesn’t have to worry about the quality of the images.”

1.     Data on file, as of December 22, 2020.

2.     Compared with previous software versions. Data on file at Align Technology, as of March 29, 2021.

3.     Only available on iTero Element 5D Plus imaging systems (full and Lite software configurations).

*iTero Element 5D Imaging systems include iTero Element 5D and iTero Element 5D Plus series scanners.

About Align Technology, Inc.

Align Technology designs, manufactures and offers the Invisalign system, the most advanced clear aligner system in the world, iTero intraoral scanners and services, and exocad CAD/CAM software. These technology building blocks enable enhanced digital orthodontic and restorative workflows to improve patient outcomes and practice efficiencies for over 200 thousand doctor customers and is key to accessing Align’s 500 million consumer market opportunity worldwide. Align has helped doctors treat over 10.9 million patients with the Invisalign system and is driving the evolution in digital dentistry through the Align Digital Platform, our integrated suite of unique, proprietary technologies and services delivered as a seamless, end-to-end solution for patients and consumers, orthodontists and GP dentists, and lab/partners. Visit www.aligntech.com for more information.

For additional information about the Invisalign system or to find an Invisalign doctor in your area, please visit www.invisalign.com. For additional information about iTero digital scanning system, please visit www.itero.com. For additional information about exocad dental CAD/CAM offerings and a list of exocad reseller partners, please visit http://www.exocad.com.

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“Optimized for Invisalign Aligners and Vivera Retainers Powered by Ultradent’s Opalescence Tooth Whitening Systems”

Align Technology, Inc. (“Align”) (Nasdaq: ALGN) a leading global medical device company that designs, manufactures, and sells the Invisalign system of clear aligners, iTero intraoral scanners, and exocad CAD/CAM software for digital orthodontics and restorative dentistry, today announced an exclusive supply and distribution agreement with Ultradent Products Inc., a leading developer and manufacturer of high-tech dental materials, devices, and instruments worldwide.

As part of the multi-year agreement, Align will offer Invisalign trained doctors an exclusive professional whitening system with the leading Opalescence PF whitening formula from Ultradent, optimized for use with Invisalign clear aligners and Vivera retainers. The system will carry the co-branded name of ‘Invisalign Professional Whitening System – powered by Opalescence’ and will offer the same great whitening outcomes and streamlined practice experience dental professionals expect from the Opalescence PF product during active tooth movement with Invisalign aligners, as well as during passive retention using Vivera retainers. The Invisalign Professional Whitening System will be commercially available globally in 2022.

“A brighter, whiter smile is an important part of the Invisalign patient journey. In fact, a survey of North American Invisalign practices (1) shows that half of their patients ask for teeth whitening during or after they complete Invisalign treatment,” said Raj Pudipeddi, Align Technology chief product and marketing officer, and SVP and managing director of the Asia Pacific Region. “We believe that by providing an all-in-one solution that combines a leading teeth-whitening system with the most advanced clear aligner system in the world, we enable Invisalign trained doctors to enhance their patients’ treatment experience with a seamless workflow that also enables practice efficiency and growth. We’re very excited to partner with Ultradent to offer the first professional whitening system optimized for use with Invisalign clear aligners and Vivera retainers. Invisalign system trained doctors can use Opalescence PF for in-office teeth whitening treatment and for doctor supervised at-home whitening.”

“We’re honored to partner with Align to make the top professional teeth whitening products available to more clinicians and patients around the world,” said Ultradent President and CEO Dirk Jeffs. “Providing Align with teeth whitening products, ideal for use with Invisalign aligners and Vivera retainers, is a considerable step toward our mission of improving oral health globally and we look forward to pursuing this mission together.”

“Many of my patients would like whiter teeth as well as a straighter smile,” said Dr. Brian Amy, an orthodontist and Align Faculty member practicing in Oklahoma City. “The new Invisalign Professional Whitening System allows me to provide both simultaneously using the brands I trust.”

“After testing this system in my practice, I can confirm that the Invisalign Professional Whitening System is easy to administer and offers a great patient experience by combining whitening with Invisalign aligners or Vivera retainers,” said Dr. Jennifer Bell, a restorative and cosmetic dentist and Align GP Advisory Board Member practicing in Holly Springs, North Carolina. “The simple ordering mechanism minimizes burden on my practice to store and manage whitening products, while providing the brighter, whiter smiles we have come to expect from the Opalescence PF product.”  

Ultradent is an ISO13485 certified facility and will manufacture the products according to those standards.

(1) 2017 online survey of Invisalign doctors, data on file at Align Technology.

About Align Technology, Inc.

Align Technology designs, manufactures and offers the Invisalign system, the most advanced clear aligner system in the world, iTero intraoral scanners and services, and exocad CAD/CAM software. These technology building blocks enable enhanced digital orthodontic and restorative workflows to improve patient outcomes and practice efficiencies for over 200 thousand doctor customers and is key to accessing Align’s 500 million consumer market opportunity worldwide. Align has helped doctors treat approximately 10.9 million patients with the Invisalign system and is driving the evolution in digital dentistry through the Align Digital Platform, our integrated suite of unique, proprietary technologies and services delivered as a seamless, end-to-end solution for patients and consumers, orthodontists and GP dentists, and lab/partners. Visit www.aligntech.com for more information.

For additional information about the Invisalign system or to find an Invisalign doctor in your area, please visit www.invisalign.com. For additional information about iTero digital scanning system, please visit www.itero.com. For additional information about exocad dental CAD/CAM offerings and a list of exocad reseller partners, please visit www.exocad.com.

About Ultradent Products, Inc.

Ultradent Products, Inc., is a leading developer and manufacturer of high-tech dental materials, devices, and instruments worldwide. Ultradent’s vision is to improve oral health globally. Ultradent also works to improve the quality of life and health of individuals through financial and charitable programs. For more information about Ultradent, call 800.552.5512, visit ultradent.com or find us on LinkedIn, Facebook, and Instagram.

Forward-Looking Statements

This news release contains forward-looking statements, including the expectations for and the terms of the agreement between Align and Ultradent the availability and capabilities of the combined Invisalign aligner and Opalescence offering, our beliefs regarding the market for the combined offering and the potential benefits to doctors, their offices and patients, and other similar comments or statements that are forward-looking in nature. Forward-looking statements contained in this news release relating to expectations about future events or results are based upon information available to Align as of the date hereof. Readers are cautioned that these forward-looking statements are only predictions and are subject to risks, uncertainties, and assumptions that are difficult to predict. As a result, actual results may differ materially and adversely from those expressed in any forward-looking statement.

Factors that might cause such a difference include, but are not limited to:

• the impact of the COVID-19 pandemic on the health and safety of our employees, customers, patients, and our suppliers, as well as the physical and economic impacts of the various recommendations, orders, and protocols issued by local and national governmental agencies in light of continual evolution of the pandemic, including any periodic reimplementation of preventative measures in various global locations;
• difficulties predicting customer and consumer purchasing behavior and changes in consumer spending habits as a result of, among other things, prevailing economic conditions, levels of employment, salaries and wages, and consumer confidence, particularly in light of the pandemic and as pandemic-related restrictions are eased regionally and globally;
• unexpected or rapid changes in the growth or decline of our domestic and/or international markets;
• increasing competition from existing and new competitors;
• rapidly evolving and groundbreaking advances that fundamentally alter the dental industry or the way new and existing customers market and provide products and services to consumers;
• the ability to protect our intellectual property rights;
• continued compliance with regulatory requirements;
• declines in, or the slowing of the growth of, sales of our intraoral scanners domestically and/or internationally and the impact either would have on the adoption of Invisalign products;
• the willingness and ability of our customers to maintain and/or increase product utilization in sufficient numbers;
• the possibility that the development and release of new products or enhancements to existing products do not proceed in accordance with the anticipated timeline or may themselves contain bugs or errors requiring remediation and that the market for the sale of these new or enhanced products may not develop as expected;
• a tougher consumer demand environment in China generally, especially for manufacturers and service providers whose headquarters or primarily operations are not based in China;
• the risks relating to our ability to sustain or increase profitability or revenue growth in future periods (or minimize declines) while controlling expenses;
• the impact of excess or constrained capacity at our manufacturing and treat operations facilities and pressure on our internal systems and personnel;
• the compromise of customer and/or patient data for any reason;
• the timing of case submissions from our doctors within a quarter as well as an increased manufacturing costs per case;
• foreign operational, political and other risks relating to our international manufacturing operations; and
• the loss of key personnel or work stoppages.

The foregoing and other risks are detailed from time to time in our periodic reports filed with the Securities and Exchange Commission, including, but not limited to, our Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the Securities and Exchange Commission (SEC) on February 26, 2021 and our latest Quarterly Report on Form 10-Q for the quarter ended June 30, 2021, which was filed with the SEC on August 4, 2021. Align undertakes no obligation to revise or update publicly any forward-looking statements for any reason.

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