Future Trends in Implant Dentistry: Digitally Guided Surgery and Prosthetics

INTRODUCTION
This article discusses an innovative and clinically accurate protocol that will assist interested dental practitioners in the delivery of full-arch fixed immediate provisional prostheses. Additionally, the detailed steps involved in converting the provisional into a fixed screw-retained final prosthesis, following sufficient healing and the osseointegration of dental implants, are outlined.

CASE REPORT
Diagnosis and Treatment Planning

A 76-year-old male patient presented to the office with Kennedy Class I partial edentulism in the maxilla (Figure 1). He had 4 anterior teeth present with one that had fractured at the gingival margin. He expressed a desire for a fixed implant-supported solution. After appropriate medical, dental, and social histories were obtained, a full clinical and radiographic examination was performed. Subsequently, it was determined that the patient had a terminal maxillary dentition and he was presented with various options.

The patient elected to have a full implant-retained prosthesis for the maxillary arch. The treatment planning and clinical procedure involved digitally guided surgery and a digitally guided provisional prosthesis. The digital protocol simplifies the steps involved in fabricating a fixed final prosthesis after subsequent healing has taken place.

To employ this protocol, the practitioner provided the laboratory team with the following:

  • Models (conventional or digital) with a face-bow registration
  • A bite registration of the patient at his “idealized” vertical dimension of occlusion (VDO)
  • CBCT at the idealized VDO
  • A series of intra- and extraoral photographs of the patient.

The company, nSequence Center for Advanced Dentistry (Reno, Nev), then digitized this information, creating a digital treatment plan to allow the practitioner and patient to visualize the outcome prior to surgery (Figure 2).

Figure 1. Retracted preoperative presentation.
Figure 2. A digital treatment plan was requested and provided.

Digitally Guided Surgical and Prosthetic Phases
Check Bite—A hard acrylic bite was fabricated by the laboratory team, based upon the initial patient records (Figure 3). The “check bite” step verifies the accuracy of the merged data, and the practitioner can feel confident that the digital records correctly represent the clinical situation.

Placement of the foundation guide—Once the patient’s maxillary teeth were extracted and a full-thickness flap was raised to expose the entire alveolus, the “foundation” guide was placed to fit over the alveolus (Figure 4). This foundation guide remains in place until the time that the provisional prosthesis is inserted. The patient bites into the struts of the guide, which helps to stabilize and position the foundation guide.

Once fully seated, guided fixation pins were placed using depth control to secure the guide by engaging both the buccal and palatal bone.

After removal of the positioning struts, the foundation guide directed subsequent bone reduction. Bone reduction was achieved using a Rongeur’s forceps. Any larger bone fragments were preserved to fill the extraction sockets. A bur (Pikos bone block contouring bur [Salvin Dental Specialties]) was used to smooth the alveolus until flush with the foundation guide (Figure 5).

Figure 3. Lab-fabricated hard acrylic bite. Figure 4. After extraction of maxillary teeth and a full-thickness flap, the “foundation” guide was placed over the alveolus.
Figure 5. The alveolus was smoothed with a bur until flush with the foundation guide. Figure 6. An implant placement guide was indexed to fit into the foundation guide.
Figure 7. Implants were placed, and then the implant placement guide was detached from the foundation guide. Figure 8. Abutments were placed, and then the abutment placement guide was removed.
Figure 9. Pretrimmed temporary
titanium cylinders, hand-tightened to the multiunit abutments (MUAs). Block-out tubes were placed in cylinders to protect prosthesis screws.
Figure 10. A flexible silicone gasket was then placed over the temporary titanium cylinders.
Figure 11. The gasket blocked out undercuts and helped position the provisional. Figure 12. Picking up the provisional clear duplicate.


Placement of the implants—An implant placement guide (patented by the laboratory [nSequence Center]) was indexed to fit into the foundation guide (Figure 6). This assisted in the sequential osteotomy process, preparing the implant sites. Once the implants were placed, the implant placement guide was detached from the foundation guide (Figure 7).

Placement of the multiunit abutments (MUAs)—An indexed abutment placement guide was then fit into the foundation guide. A specific guide was created to assist in the placement of the angled MUAs to ensure correct positioning. The abutments were then placed and torqued per the manufacturer’s recommendations, and then the abutment placement guide was removed (Figure 8).

Placement of the temporary titanium cylinder—Pretrimmed temporary titanium cylinders were subsequently hand-tightened to the MUAs. Block-out tubes were then placed into these cylinders to protect the prosthesis screws (Figure 9).

Figure 13. The silicone maxillary gasket, fixation pins, and foundation guide were removed. Figure 14. The finished provisional prosthesis.
Figure 15. Panoramic radiograph of and anterior photo of the bar-supported provisional prosthesis.

Placement of the silicone gasket and fit of the provisional—A flexible silicone gasket was then placed over the temporary titanium cylinders, hugging the apical portion of the cylinders tightly (Figure 10). The gasket served to block out undercuts and to guide the apical and lateral position of the provisional (Figure 11), while taking into account the thickness of the underlying soft tissue. The provided silicone bite registration index was placed against the incisal edge of the provisional and indexed to the patient’s mandibular incisors, and thus stabilized the prosthesis at the patient’s idealized VDO.

Picking up the provisional prosthesis and clear duplicate—After stabilizing the prosthesis, a dual-cured polymer (Triad [Dentsply Sirona]) was used to “pick up” the cylinders after injecting material into the small buccal channels. After curing the polymer from the buccal, the silicone bite registration was removed. Next, any remaining voids were then filled with the polymer and light-cured from the occlusal aspect. Then, the block-out tubes were removed and the prosthesis was unscrewed and removed from the mouth. This step was then repeated using a second set of titanium cylinders and the clear duplicate prosthesis supplied by the laboratory team (Figure 12). This clear duplicate prosthesis was then stored for future use after the healing period elapsed to help fabricate the final fixed prosthesis.

Removal of guide and closure—The silicone maxillary gasket was then removed along with the fixation pins and foundation guide (Figure 13). The alveolus was then smoothed and contoured and the earlier harvested autogenous bone used to fill the remaining sockets. Closure was achieved by placing individual interrupted sutures between the implants.

Finishing and insertion of the provisional prosthesis—After adding acrylic to fill any remaining voids around the titanium cylinders, the provisional was further cured with heat and pressure before giving its final polish. Next, the finished provisional prosthesis was placed onto the MUAs and torqued into place per the manufacturer’s specifications (Figure 14). Teflon tape and Cavit [3M] were then used to close each access hole before verification of the patient’s occlusion. This bar-supported, monolithic polymethyl methacrylate acrylic (PMMA) prosthesis would then be worn for approximately 6 months (Figures 15 and 16).1

Digitally Guided Final Prosthetic Phase
During the healing phase, the provisional prosthesis was not removed. It served as a “splint” for the implants, helping to stabilize them during the healing process.2,3 After the 6-month healing period,1 the patient returned with his PMMA provisional prosthesis in place. Upon examination, his occlusion remained stable, well balanced, and unchanged from his initial immediate postoperative position (Figure 16a). The prosthesis, although a little worn and mildly stained, was still functional and showed good aesthetics (Figure 16b).

Figure 16. The provisional prosthesis was stable and unchanged at 6 months.
Figure 17. Some inflammation in the tissues was noted after wearing the provisional prosthesis continuously for an extended period of time.
Figure 18. Using a torque wrench with a multiunit adapter, the stability of each implant was tested. Figure 19. One implant did not
successfully osseointegrate and was subsequently removed.
Figure 20. The stored clear duplicate was retrieved and inserted. Figure 21. The prosthesis was
hand-tightened over the MUAs.
Figure 22. The intaglio surface of the clear duplicate and underlying soft tissues were air-dried.

Removal of the provisional prosthesis—The access holes of the provisional prosthesis, which had been closed off with Cavit and Teflon tape, were uncovered. The screws were untorqued, and the prosthesis was removed and cleaned with a chlorhexidine solution (Chlorhexidine Gluconate 0.12% Oro-Cleanse [Germiphene]). Upon inspection of the tissues underlying the prosthesis, the general health of the tissues was fair with some inflammation consistent with expectations having worn the provisional prosthesis continuously for a long period of time (Figure 17).

Verification of the stability of the implants—Using a torque wrench with a multiunit adapter, the stability of each implant was tested (Figure 18). This test serves 2 purposes: first, the abutments are tightened against the implant as they can loosen with time; and second, the bone-implant interface is placed under strain to evaluate its strength at a force of 30 Ncm. If the bone-implant contact is unstable, the implant will rotate. In this case, one implant did not successfully osseointegrate and was subsequently removed (Figure 19). There was no need to replace the failed implant. The design of the final prosthesis would be stable, balanced, and functional using the remaining 7 implants and their anterior-posterior spread.4 The original treatment plan accounted for the potential failure of one or 2 of the implants without the need for additional surgery.

Fit and use of the clear duplicate—The stored clear duplicate was retrieved and inserted into the patient’s mouth (Figure 20). The prosthesis was hand-tightened over the MUAs. The fit was found to be precise and required no adjustment (Figure 21). This predictable fit was a result of the stabilization and splinting of the implants after surgery while the patient wore his PMMA provisional prosthesis. There may be a gap between the clear duplicate and the ridge as some tissue shrinkage is a normal sequelae of the healing process. If there is not an adequate amount of clearance, the intaglio side of this duplicate provisional must be relieved using an acrylic bur to create the required space for the impression material.

Radiographs were then taken to ensure this duplicate was seated properly prior to the next steps.

Impression of the arch and pickup of the implant/MUA positions—Once the seating has been verified and prior to taking an impression, it is important to confirm that the clear provisional duplicates the aesthetics of the provisional prosthesis. (In this practitioner’s experience, this has never been an issue, as the clear duplicate and provisional prosthesis are fabricated together using the same digital technology and processes prior to the surgical procedure.)

Figure 23a. Using retractors, light-body vinyl polysiloxane (VPS) impression material (Examix NDS [GC America]) was injected into the gap area between the tissues and the clear duplicate from both the palatal and buccal. Figure 23b. The VPS material was extruded to record the facial and palatal contours of the ridge.
Figure 23c. A bite registration was taken simultaneously with the patient in centric relation.
Figure 24. Once the materials were fully set, the bite registration was carefully removed, the clear duplicate unscrewed and removed. Figure 25. The lab team (nSequence Center for Advanced Dentistry; Reno, Nev) then fabricated a metal framework with access holes where the implants are located for the final prosthesis.
Figure 26. The patient returned to the office at approximately 2 weeks for the metal framework try-in.

The intaglio surface of the clear duplicate and underlying soft tissues were air-dried (Figure 22). Using retractors, light-body vinyl polysiloxane (VPS) impression material (Examix NDS [GC America]) was injected into the gap area between the tissues and the clear duplicate from both the palatal and buccal. With the tip inserted inside the gap area, the impression material was gently extruded while the tip was carefully pulled out (Figure 23a). This process ensures that there is adequate impression material in this area to adequately capture the gingival tissues that have recontoured during the healing phase. The VPS material was also extruded to record the facial and palatal contours of the ridge (Figure 23b). The accuracy of the vestibular contours was not critical in this procedure, as a fixed prosthesis was treatment planned for the patient rather than a conventional full denture. A bite registration was also taken simultaneously with the patient in centric relation (Figure 23c).

Once the materials were fully set, the bite registration was carefully removed and the clear duplicate unscrewed and removed from the mouth (Figure 24). The impression was examined carefully to ensure that the intaglio surface of the denture had accurately recorded the gingival contours and there were no serious deficiencies. The PMMA provisional prosthesis was then re-inserted for the patient, and radiographs taken to ensure that the prosthesis was seated and fit appropriately.

Figure 27. Radiographs were taken and a screw test done to confirm an accurate and passive fit of the framework.
Figure 28. Completed maxillary implant-retained prosthesis.

Laboratory fabrication of the final fixed prosthesis—Next, the impression was sent to the laboratory, where the lab team would attach MUA analogs and pour a model to become an accurate representation of the patient’s arch and implant/MUA positions (master model). This master model was cross-mounted with the bite registration and the previous mounted mandibular cast. The lab team then fabricated a metal framework with access holes where the implants were located for the final prosthesis. On this screw-retained prosthesis, each final crown restoration was made to fit the individual crown preparations on the framework (Figure 25). In this case, milled lithium disilicate (IPS e.max CAD [Ivoclar Vivadent]) crowns were prescribed.

Try-in of the metal framework—The patient returned to the office in approximately 2 weeks to try in the metal framework (Figure 26). Radiographs were taken and a screw test done to confirm an accurate and passive fit of the framework (Figure 27).5,6 The occlusion and VDO were verified and a final shade selected.

Finalization of the prosthesis by the laboratory team—The laboratory finished the case by milling the lithium disilicate crowns, and then adding pink porcelain to the metal framework to mimic the gingiva and soft tissues. Access holes were created in the crowns where the screws were located. Finally, the crowns were then cemented onto the framework at the laboratory using permanent cement.

Insertion of the final fixed prosthesis—The patient returned to the clinic, and the provisional PMMA prosthesis was removed and the final prosthesis delivered. The access holes are filled with Cavit and Teflon tape, and the excess material removed. The aesthetics, occlusion, and VDO were verified. The patient was very pleased with the final outcome (Figure 28).

DISCUSSION
This innovative technique (patented by nSequence) uses integrated digital technology to achieve a predictable prosthetic result.7 As noted herein, each sequential step was guided by the initial treatment planning, ensuring accuracy of fit in each surgical and prosthetic phase. The aesthetics and function of the final prosthesis were predictable and unchanged from the provisional phase through the delivery of the fixed prosthesis. This instilled confidence between the clinician and the patient, as they worked together in the treatment planning and consultation phases to reach this outcome.

This technique is very time efficient for both the clinician and the patient. The guided surgical and guided prosthetic protocol enable a faster and more accurate placement of implants and provisional prosthesis without any guesswork, as is required in other “freehand” methods.8-10 Additionally, the fabrication of the final prosthesis requires fewer appointments as several clinical steps (including the verification jig, occlusal rim, and wax setup) are eliminated as a direct result of the digital solution provided by this methodology. The clear duplicate serves as an impression tray as well as a verification jig to ensure the accuracy of the implant/MUA positions in the master model. Also, the use of the clear duplicate mimics the size and shape of the teeth at the correct VDO for the final prosthesis; thus, there is no need for wax occlusal rims or a wax tooth setup. For the patient, this is advantageous as (potentially) 3 appointments are eliminated. It is noteworthy to mention that, with experience and developed expertise, the metal framework try-in appointment can often be eliminated given the high level of accuracy of the master model.

This protocol will support the use of various restorative materials for the final prosthesis. However, the main advantage of using a framework with individual CAD/CAM crowns is the ease with which replacement crowns can be fabricated in the event the patient fractures one since a digital record is kept. If one crown chips, it can be removed and provisionalized while the lab team is instructed to fabricate a replacement crown. It is unnecessary to remove and send the entire prosthesis back to the laboratory. Additionally, the lab team could even fabricate the replacement crown before the patient presents to the office, as long as the practitioner knows ahead of time which crown is compromised.

IN SUMMARY
The use of digital technology and CAD/CAM solutions creates a high degree of predictability for the practitioner. The preplanned surgical phase, including the foundation and implant placement guides, reduces the stresses involved in determining optimal implant placement sites for prosthetic rehabilitation.11 Using the clear duplicate protocol eliminates the inaccuracies of impression materials for the implant and/or MUA positions. This translates into a more passive fitting prosthesis5 along with predictable aesthetics. Ultimately, this is a win-win situation for the patient and the clinician.


References

  1. Brånemark PI, Albrektsson T. Microcirculation and healing of artificial implants in bone. In: Proceedings of the 2nd World Congress for Microcirculation. Cambridge, MA: Academic Press; 1979:59-60.
  2. Schnitman PA, Wöhrle PS, Rubenstein JE, et al. Ten-year results for Brånemark implants immediately loaded with fixed prostheses at implant placement. Int J Oral Maxillofac Implants. 1997;12:495-503.
  3. Wang TM, Leu LJ, Wang J, et al. Effects of prosthesis materials and prosthesis splinting on peri-implant bone stress around implants in poor-quality bone: a numeric analysis. Int J Oral Maxillofac Implants. 2002;17:231-237.
  4. Rodriguez AM, Aquilino SA, Lund PS. Cantilever and implant biomechanics: a review of the literature, Part 2. J Prosthodont. 1994;3:114-118.
  5. Sahin S, Cehreli MC. The significance of passive framework fit in implant prosthodontics: current status. Implant Dent. 2001;10:85-92.
  6. Kan JY, Rungcharassaeng K, Bohsali K, et al. Clinical methods for evaluating implant framework fit. J Prosthet Dent. 1999;81:7-13.
  7. Pikos MA, Magyar CW, Llop DR. Guided full-arch immediate-function treatment modality for the edentulous and terminal dentition patient. Compend Contin Educ Dent. 2015;36:116-128.
  8. Rosenfeld AL, Mandelaris GA, Tardieu PB. Prosthetically directed implant placement using computer software to ensure precise placement and predictable prosthetic outcomes. Part 1: diagnostics, imaging, and collaborative accountability. Int J Periodontics Restorative Dent. 2006;26:215-221.
  9. Pikos MA, Mattia AH. Implant surgery interventions: Three-dimensional reverse tissue engineering for optimal dental implant reconstruction. In: Jokstad A, ed. Osseointegration and Dental Implants. Ames, IA: Wiley-Blackwell; 2008:197-204.
  10. Worthington P, Rubenstein J, Hatcher DC. The role of cone-beam computed tomography in the planning and placement of implants. J Am Dent Assoc. 2010;141(suppl 3):19S-24S.
  11. Wong NY. Predictable immediate implant prosthetics using guided surgery and guided prosthetics: a case report. Oral Health. 2016;106:66-78.

Dr. Wong graduated from the University of Toronto with a DDS (1996) and received her certificate in prosthodontics from the University of Michigan (2007). She is the only dentist who has attained a combination of the US board certification in implant dentistry (Diplomate from the American Board of Oral Implantology [ABOI], 2003), US board certification in prosthodontics (Diplomate of American Board of Prosthodontics, 2008), and Canadian board certification in prosthodontics (Fellow of Royal College of Dentists of Canada, 2008). She is a Diplomate of the International Congress of Oral Implantologists and holds Fellowships with the AGD, American Academy of Implant Dentistry (AAID), and the Misch International Implant Institute in Canada, where she is also a faculty member. She has served as a clinical instructor in the implant prosthodontic unit in the graduate prosthodontic department at the University of Toronto. She is past president of the ABOI, the current treasurer for the AAID, president of the Association of Prosthodontists of Ontario, and founder and director of the Toronto Implant Institute. She lectures internationally on implant dentistry and continues to practice implantology in Toronto. She can be reached by email at the following address: This email address is being protected from spambots. You need JavaScript enabled to view it..

Disclosure: Dr. Wong is a consultant for BioHorizons.

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Use of Superior Prosthetic Technique to Overcome Compromised Implant Placement

Proper placement of implants is critical in order to achieve the best possible aesthetic results. This is especially true in the maxillary anterior region. Extreme bone loss in an edentulous area presents a challenge to ideal implant placement. Several bone grafting techniques have evolved over the years to enable us to attain our goals. Each of these techniques has its advantages and disadvantages and therefore we must use our clinical judgment to decide which technique to pursue.

The techniques considered for ridge augmentation in this clinical case were:

  • Autogenous block onlay bone grafting.
  • Nonautogenous block onlay grafting.
  • Segmental ridge splitting.
  • Particular bone grafting.

Autogenous Block Onlay Bone Grafting

Autologous bone grafting used with dental implant was originally introduced by Brånemark et al in 1975.1 This technique involves harvesting bone from a recipient site such as the ramus of the mandible or mandibular symphysis and transplanting this block of bone to a recipient site. This technique can result in significant increases in width but less predictable to increase alveolar height. It involves surgery on a secondary site and it is thus more invasive and traumatic, which leads to higher morbidity of the donor site ie, impaired sensibility to teeth, gingiva, and skin. Another big disadvantage is the significantly high cost of this procedure compared to the others.

Nonautogenous Block Bone Grafting

The big advantage of this technique is that since the material is artificially produced, it eliminates the need for an additional surgical procedure to procure bone from a donor site. However in addition to having the same other drawbacks as the autogenous bone graft, this method is very technique sensitive. It must retain primary closure throughout the healing phase, otherwise it will fail. Failure of either block technique can result in a worse situation than the original.

Segmental Ridge Splinting

The segmental ridge split procedure creates a crypt surrounded by bone and periosteum into which implants and bone graft materials can be introduced with treasonable confidence that new bone can be constructed and that this new bone will provide a solid base for dental implants. Razor sharp bone chisels and a mallet are used to split the alveolar ridge. An implant is placed between the 2 cortical plates along with particulate bone graft material. This procedure is extremely technique sensitive and requires careful case selection. A ridge that is too narrow mesiodistally or buccolingually is almost impossible to split cleanly, and thus presents a high risk of resulting in a far worse situation than originally. It also does not address the loss of alveolar height.

Particular Bone Graft

Bone grafting using particulate material has also been done since the earliest days of osseointegrated implants. Materials have included freeze-dried allograft from tissue banks and nonallograft hydroxyapatite materials. Different particulate materials are supposedly used for osteoinductive and osteoconductive properties. The synthetic hydroxyapatite materials are mainly thought to maintain space and provide a scaffold in which natural bone can form. Different membranes are usually placed over the particulate graft material to both keep the material in place and exclude early migration of epithelial cells before osteoblasts have a chance to migrate and produce bone. Particulate grafting is the most widely used technique because it is less sensitive, less morbid, doesn’t require a donor site and is comparatively much more affordable to patients. It can be used for onlay grafting to increase width and height as well.

Yet even despite our best efforts, an implant may not end up in an ideal position. It is situations like these where expert prosthodontics can compensate and overcome a less than ideal implant position to attain a highly satisfactory result.

CASE REPORT

A 42-year-old female patient presented with a missing maxillary left central incisor with a severely atrophic localized edentulous ridge (Figures 1 and 2). Atrophy of the alveolar ridge had occurred in width as well as vertically.

Figure 1. Initial preoperative view from labial from July 14, 2007. Tooth No. 9 missing.

Figure 2. Initial preoperative view from occlusal from July 14, 2007.

The treatment plan comprised first onlay bone grafting to increase height and width prior to placement of an implant and ultimately placement of a crown.
             
First Stage Surgery

Under local anesthesia, an incision was made from the distal line angle of No. 8 to the distal line angle of No. 10. Vertical incisions were extended at each line angle. A full thickness flap was elevated exposing a “knife edge ridge” of less than 1 mm thickness in the area of No. 9 and approximately 6 mm loss in vertical bone height at the center (Figure 3). Small perforations were made in the bone to create bleeding surfaces (Figure 4). A combination of large particle cortical PUROS bone graft material with Bio-Oss, a synthetic hydroxyapatite graft material was used (Figure 5). Graft material was placed on both labial and palatal sides of the ridge. The graft was then covered with BIO-GUIDE resorbable membrane and held in place with 2 titanium tacs (Figure 6).

Figure 3. Preoperative view from labial of bone (alveolar ridge) with flap reflected (July 14, 2007).

Figure 4. Tenting screw in place during first bone grafting procedure (July 14, 2007).

Figure 5. Bone graft material (BIO-OSS + Puros cortical) in place during first bone grafting procedure (July 14, 2007).

Figure 6. BIOGUIDE membrane in place covering bone graft material. Membrane held in place with titanium tacks. First bone graft procedure (July 14, 2007).

The flaps were closed with 4-0 vicryl sutures (Figures 7 and 8). The patient was placed on a 7-day regimen of amoxicillin along with a chlorhexidine (Peridex) rinse. Healing was uneventful (Figure 9) and the graft site was allowed to heal for 6 months before the area was flapped open again. Modest bone augmentation (approximately 2 mm gain in thickness; one mm gain in height) had taken place, however, it was still deemed insufficient in both quantity and quality to place an implant.

Figure 7. Area sutured—occlusal view (July 14, 2007).

Figure 8. Area sutured—labial view (July 14, 2007).

Figure 9. Preoperative view—occlusal (January 12, 2008).

Additional bone grafting was done using the same materials and techniques as the first procedure (Figures 10 to 12). Again healing was uneventful and the site was allowed to heal for another 5 months (Figure 13). The site was again flapped open revealing an additional 1- to 2-mm gain in thickness but less than a 1-mm gain in height. Bone quality was judged to be poor-fair.

Figure 10. Grafting material placed.

Figure 11. Membrane placed.

Figure 12. Sutured with BIOGUIDE membrane (January 12, 2008).

A surgical stent was used to place the implant in the correct mesial-distal position, however, in deference to the quality bone; it was decided to place the implant slightly within labial to the surgical stent position. This was done in order to place the implant completely within the labial palatal borders of the ridge rather than risk perforating or completely obliterating the palatal wall in trying for ideal location from a prosthetic point of view. Additional bone grafting was placed around the implant using a nonresorbable TEFGEN membrane (Figures 14 to 17).

Figure 13. Preoperative view prior to implant placement (June 14, 2008).

Figure 14. Implant in place—occlusal view (June 14, 2008).

Figure 15. Implant in place—labial view (June 14, 2008).

Figure 16. Bone graft (BIO-OSS + Puros cortical) in place (June 14, 2008).

Figure 17. Sutured implant in place (TEFGEN membrane, black silk sutures) (June 14, 2008).

Figure 18. Implant uncovered with cover screw in place (December 20, 2008).

Figure 19. Final prosthetic smile (December 20, 2008).

Healing was uneventful and the implant was uncovered 6 months later. The membrane was removed and a healing abutment was placed (Figure 18). The patient was referred back to the restorative dentist a few weeks later and the case was restored (Figure 19).

CLOSING COMMENTS

Extensive bone grafting was done in an effort to augment a severely atrophic edentulous single tooth area for the purpose of placing an implant. Despite these efforts, the final placement of the implant resulted in a location more labial and apical than ideally desired.


Reference

1. Brånemark PI, Lindström J, Hallén O, et al. Reconstruction of the defective mandible. Scand J Plast Reconstr Surg. 1975;9:116-128.

Suggested Readings

Listrom RD, Symington JM. Osseointegrated dental implants in conjunction with bone grafts. Int J Oral Maxillofac Surg. 1988;17:116-118.

Misch CM, Misch CE. The repair of localized severe ridge defects for implant placement using mandibular bone grafts. Implant Dent. 1995;4:261-267.

Misch CM. Comparison of intraoral donor sites for onlay grafting prior to implant placement. Int J Oral Maxillofac Implants. 1997;12:767-776.

Schwartz-Arad D, Levin L. Intraoral autogenous block onlay bone grafting for extensive reconstruction of atrophic maxillary alveolar ridges. J Periodontol. 2005;76:636-641.


Dr. Rosenstein is a periodontist in private practice in New York City and Suffern, NY. He did his undergraduate and postgraduate dental training at University of Medicine and Dentistry New Jersey Dental School, Newark, NJ, and a general practice residency at Lenox Hill Hospital, New York City. He can be reached at (845) 357-5002 or This email address is being protected from spambots. You need JavaScript enabled to view it..

Disclosure: Dr. Rosenstein reports no disclosures

A Shared Understanding: Managing Aesthetic Treatment Imperfection

INTRODUCTION
We are so hard on ourselves. Our nature as dentists is to focus on what went wrong instead of celebrating what went right. We dwell on and beat ourselves over that one patient, that one case, that one tooth that didn’t turn out as well as planned. The pain from failure is often greater than the happiness from success. Why do we do that to ourselves?
We take a single patient complaint or small compromise in a case and magnify it so that we end up convincing ourselves that we don’t measure up to others in the profession. We convince ourselves that we are the only dentist who has treatment disappointments. The truth is that we all have similar struggles. Certainly, any conscientious practitioner tries hard to do quality, patient-pleasing work. Striving to become better is what keeps the spark and passion alive in our practices. We learn from our failures. We all want to become more skilled, have more clinical success, and have happier patients. To get maximum happiness and reward from our professional lives, we must learn how to plan for and deal with an imperfect outcome.

Thorough planning and communication with the patient and lab team are key. Listening to the patient, knowing patient expectations, identifying limitations, and dwelling on the positive are all important steps for reducing tension later. There must be a shared understanding between the dental team and the patient. There are steps that can be taken to improve this shared understanding (Table).

Understanding Starts at the Patient Consult
A female patient with the desire for a better smile came to our office for an aesthetic consultation (Figure 1). Often, the road to success centers around effective photography. A few digital photos were taken by the chairside team and put up on a 35-inch monitor in the operatory and reviewed with the patient. The assigned office team member does an interview while going through each image:

  • What can we do for you?
  • What don’t you like about your smile?
  • What are the 2 most important things that you want us to correct with your smile?

These are the first steps to a shared understanding. Active listening, empathy for patient desires, and accurate documentation will help lessen disappointment later. The patient is shown the images and a list is made of what he or she does not like. Most likely, patients have never seen their teeth enlarged on a monitor; it often accentuates what they already did not like and points out flaws that they never considered.

Figure 1. At the consultation appointment, our patient stated that she wanted her smile improved.
Figures 2 and 3. A few photos were taken and reviewed with the patient, and the staff discussed the patient’s desires. Having patients evaluate themselves on large operatory monitor is very persuasive, helping the patient focus on what he or she does not like. The dentist reviews the photos again with the patient, explaining and discussing the case from a doctor’s standpoint.

In this case, the patient wanted her teeth to be in better alignment, to have the shade of her teeth improved, and to have a more youthful smile. The chairside team reports what they have learned to the doctor while the photo that best exemplifies most of the identified features that the patient did not like stays on the monitor for the patient to focus on while the doctor is briefed. Internally, we refer to this step as dwelling on the ugly.

The dentist then reviews the pictures again in front of the patient, pointing out things from the doctor’s perspective. The patient will often describe his or her desires differently to the doctor than to the clinical staff. This is where the tempering of expectations starts—to begin to curb patient expectations with regard to biologic, material, and technique limitations. It’s where desires meet reality.

Understanding Compromise
In this case, there was a missing left central incisor (tooth No. 9). A PFM bridge had been done to replace tooth No. 9, and the patient had a history of previous periodontal therapy. Her midline was off about 4.0 mm (to her right) and there was a slight cant in the PFM bridge (Figures 2 and 3). The composite veneers were leaking, with recurrent and interproximal decay on several teeth.

She had been missing tooth No. 9 for many years and had significant buccal plate and horizontal resorption. We offered the option of grafting and implant placement, and the patient declined. The pontic site would be compromised without ridge augmentation. If the patient should decline to accept recommended procedures, those compromises must be explained, understood by the patient, and documented.

After reviewing and agreeing that her gum tissue did not show in the photos, a compromise was agreed upon (this was the first compromise).

Tooth No. 7 was facially inclined and flared. We pointed out that the tooth may be a limiting factor in keeping the new restorations from looking bulky. The choices were extraction, an additional pontic, or implant placement. We agreed that leaving it in place, reducing what we could, and then evaluating the bulkiness of the temporary would be our plan. Another potential compromise.

When patients want whiter teeth, the challenge becomes what we will do with the lower teeth. She could not afford to veneer them, so bleaching was discussed. Promising the patient that we could predictably bleach her lower teeth to match her goal of 0M2 on the maxilla, a shade she chose with the assistant, would be misleading. Therefore, with her understanding, a slightly darker shade on the maxilla, 0M3, was chosen in case bleaching was not effective or maintained on the mandibular teeth. This was one more compromise chosen by the patient.

Figure 4. Lab team involvement with a detailed and shared understanding of the case is vital to success. A wax-up, reduction guide, and temporary matrix are all important communication tools. Figure 5. The lab team also provided a
soft-tissue modification plan that was created according to model/photographic analysis.
Figure 6. The diode laser (Picasso Lite [AMD LASERS]) was used to increase symmetry and to create more aesthetic soft-tissue contours. Figure 7. Decay removal, composite buildups, and consistent preparations are the basis for long-term success.
Figure 8. The preparations were checked using the lab-fabricated reduction guide. In this case, the position of the laterals were a potential aesthetic compromise if left in place. Figure 9. Preps were completed and a shade photo taken for the lab team.
Figure 10. Temporaries were made from the wax-up matrix in a shade that the patient desired as the final shade. Review was done 3 to 5 days after the preparation appointment, and the evaluation results were communicated with the lab team.

So what can’t we do? Pointing out the limitations of treatment versus her needs and wants must start early. It is important not to use words like permanent, exactly, perfect, and other words that imply that we will meet all the patient’s goals, regardless of biologic or material limitations. Everyone must be on board before treatment as to the degree of non-perfection that may be expected.

Lab Team Involvement
Having input from the dental laboratory team on a case like this is critical to the proper treatment planning of a comprehensive or cosmetic case. Often, the ceramist will come up with ideas to help treatment that the office team and doctor did not think of or consider. Having the lab team involved before beginning the actual clinical work obviously helps to make the treatment appointment more efficient, but even more importantly, there is the peace of mind that the clinician has by getting input from someone else about the case. It’s amazing how often the ceramist will think of something the doctor overlooked.

Alginate substitute (Silginat [Ket­tenbach LP]) was used to make accurate pre-op impressions. These were sent to the lab with a full series of photos, bite registration, and our stated goals for the case. We also supplied incisor measurements and what we thought would be the correct incisal position.

The dental technician then waxed up the teeth, made prep reduction guides (Figure 4), and a soft-tissue modification plan (Figure 5) according to the photos and treatment goals sent. The soft-tissue modification plan provides the clinician a basic blueprint for precise diode laser tissue recontouring without regard to biologic limitations.

Review of Expectations Before Treatment
At a case presentation appointment (or on preparation day), the chairside team reviews the plan. The patient is reassured about making great choices with treatment and how excited the team is to provide treatment as agreed upon. In our practice, we don’t go into a great amount of detail about upcoming treatment, but instead, we do deliver a pleasant and positive outline of what will be done during the appointment. The staff is trained to talk to the patient about how meticulous and thorough the doctor is and that excellence is the goal of the entire team. The tone is that of positive reassurance.

Clinical Treatment
After the treatment review, the patient was given local anesthetic. After bone sounding with a sharpened periodontal probe, it was verified that soft-tissue recontouring could be successfully done using a diode laser (Picasso Lite [AMD LASERS]). The author’s goal is to keep the final restoration margins 2.5 to 3.0 mm from the bony crest to prevent biologic width violations and to prevent chronically red or inflamed gingiva. Other areas were also shaped; this was done according to tissue type, location, and restoration margin extension (Figure 6).

Depth cuts were made and tooth preparation completed. All corners were rounded and the preparations were smoothed (Figure 7). Then the reduction guide was inserted and the tooth preparations were inspected (Figure 8).

Figure 11. A zirconia framework (layered) bridge (Lava Plus [3M]) was made from maxillary cuspid-to-cuspid, with individual layered zirconia crowns (Lava Plus) on the maxillary bicuspids. Figure 12. After try-in, the restorations were cleaned (Ivoclean [Ivoclar Vivadent]).
Figure 13. The teeth were isolated and cleaned with pumice (Preppies [Whip Mix]) and then 2% chlorhexidine (Cavity Cleanser [BISCO Dental Products]). Figure 14. Retention to the large composite buildups (Core-Flo DC [BISCO Dental Products]) was increased using air abrasion with 50-µm aluminum oxide.
Figure 15. A dual-cure universal bonding adhesive (ALL-BOND UNIVERSAL [BISCO Dental Products]) was massaged onto the teeth and air-thinned. Figure 16. Cementation was done with a self-etch self-adhesive dual-cure resin cement (BeautiCem [Shofu Dental]).
Figures 17 and 18. Photos were taken and evaluated. Perfection was nowhere to be seen, but this case was a success nonetheless.
Figures 19 and 20. Because imperfections were identified and managed throughout treatment, the patient’s and treatment team’s expectations were met. Focusing on the negative must be minimized and the overall benefit must be learned to be accepted.

Both lateral incisors involved preparation challenges. Tooth No. 7 was too far facial, and to reduce it enough for 2.0 to 3.0 mm clearance was not possible without compromising its strength. Having discussed this issue previously with the patient, this made our decision to leave it under-prepared facially more acceptable, and we would re-evaluate this issue in the provisional restoration phase. Tooth No. 10 was in the center of the proposed contact between it and the pontic. To reduce the tooth so it fit into the proper position, it would have to be prepped into the pulp and reduced to the point of questionable bridge abutment support. The effect of this compromise could result in an incorrect midline or tooth proportions that would not be acceptable. In this case, the compromise was made by the doctor to add another abutment to the bridge and to evaluate this during the temporary restoration phase as well.

Shades of the prepared teeth were taken to help the ceramist in choosing opacities and final shades (Figure 9). Full-arch vinyl polysiloxane (VPS) impressions (Panasil [Kettenbach LP]), a bite registration (Futar [Kettenbach LP]) and alignment guides, and an articulation record (Kois Dento-Facial Analyzer [Panadent]) were all taken and sent to the lab team. A temporary was made using the lab-fabricated matrix using a composite material (Luxatemp [DMG America]) in the shade the patient chose for the final restorations.

The Temporary Restoration Phase
One of the most important steps in a complex case is the temporary phase. It allows the patient the chance to preview basic shape, size, color, and incisal edge position based on the lab wax-up. These living and modifiable transitional restorations give the patient a preliminary chance to view the size, shape, and color that we desired for the case.

Five days after the preparation appointment, the patient returned, and the temporary bridge was evaluated (Figure 10). The patient was asked about aesthetics, speech, comfort, length, and color. The patient then signed a shade agreement form of the final shade (the same, lighter, or darker than the temporary/transitional restorations). Any needed adjustments were made, then photos and impressions of the temporary restorations were taken and sent to the lab team along with a brief description of the patient experience/feedback.

Preparation compromises and their aesthetic effect were also evaluated in the temporary phase before the final restorations were made. In this process, there must be a shared understanding among the staff, the doctor, and the patient.

Restorations
A 6-unit layered zirconia anterior bridge (Lava Plus [3M]) was made along with layered zirconia (Lava Plus) bicuspids (Figure 11). The lab made them based on the wax-up and a few corrections we made in the temporaries. All restorations were tried in for fit and aesthetics, cleaned using a universal cleaning gel (Ivoclean [Ivoclar Vivadent]) (Figure 12), and then rinsed thoroughly and dried with oil-free air. The teeth were cleaned using flour pumice (Preppies [Whip Mix]) (Figure 13) and then 2% chlorhexidine (Cavity Cleanser [BISCO Dental Products]). The retention to large composite resin buildups (Core-Flo DC [BISCO Dental Products]) was increased using air abrasion with 50-μm aluminum oxide (Figure 14).

A dual-cure universal adhesive (ALL BOND UNIVERSAL [BISCO Dental Products]) was massaged onto the tooth surfaces and air-thinned (Figure 15), followed by cementation with a self-etch, self-adhesive, dual-cure resin cement (BeautiCem [Shofu Dental]) (Figure 16). (The bridge was cemented first followed by the bicuspids.) After cleanup of any excess cement, the margins were fully light-cured (Elipar S10 [3M]). Finally, the occlusion was checked and adjusted as needed, and then the restorations were polished (CeraMaster [Shofu Dental]).

Celebrating Victory
We emphasize the positive; it rubs off onto the patient. At the insertion and at follow-up appointments, everyone in the office tells patients how great they look. “Wow, that’s one of the best cases the doctor has ever done. You look terrific.” Of course, we listen to any patient concerns and address any identified issues, but the goal is to do our best to not allow patients to control the emotion in the office by dwelling on anything that seems less than perfect to them.

CLOSING COMMENTS
As doctors, it is so important to know that we all share the same issues. The difference is in how each of us chooses to handle them. Plan for success, use all your resources to do the best, and do not beat yourself up over imperfections. If the limitations of biology, materials, and patient expectations are handled from the beginning, tension levels after the case will be lessened (Figures 17 and 18). What makes a happy patient is for the team and doctor to listen, and then to effectively communicate to the patient what can and cannot be done. Then, thorough evaluation of photos, models, and planning with the lab team will reduce stress when the case is delivered (Figures 19 and 20).

If you follow the recommendations woven into this case report article, you will improve your patients’ satisfaction. Furthermore, it will help you be happier dentist who learns to take joy in the successes, dwelling less on the dissatisfaction that is sometimes found in any necessary compromises.

Acknowledgment
The author would like to thank the Pacific Aesthetic Continuum (thepac.org) for the principles used in this case and the Pacific Aesthetic Dental Studios for their excellent case planning and restorations.


Dr. Griffin completed a general practice residency and maintains a general practice in Eureka, Mo. He focuses his clinical efforts on efficiency in almost all phases of general dentistry while providing state-of-the-art care and services for affordable fees. He centers his teaching content on increasing practice efficiency and on predictable restorative dentistry techniques. He can be reached via email at This email address is being protected from spambots. You need JavaScript enabled to view it. or via the website eurekasmile.com.

Disclosure: Dr. Griffin reports no disclosures.

Other Articles By Dr. Griffin

Focus On: Regenerative Dentistry



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