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 Multidisciplinary Anterior Trauma Case: It Takes a Team!

INTRODUCTION
Anterior trauma to the natural dentition in adults is a common occurrence that can often require a multidisciplinary approach with an organized and well-conceived treatment plan. When treatment planning these patients, thought must be given to issues dealing with restorative longevity and aesthetics. A plan must be created that makes treatment seamless for the patient’s day-to-day life, keeping in mind that our patients must continue to go about their routine during what can easily be a 6-month to one-year finality of treatment.

When dealing with substantial fractures in anterior teeth, thought must be dedicated to which of the teeth have the best long-term prognosis and what teeth, if any, may even need to be extracted. Important things to consider include deciding if implants or grafting procedures are needed, a rough timeline of treatment, and some idea of what the aesthetics and longevity can be expected out of each option.1 With the recent advances in dental research and materials, placing anterior implants and being able to control the soft- and hard-tissue architecture as well as the aesthetic outcome to mimic natural dentition is much more predictable. The surgical procedures, prosthetic sequences, as well as laboratory material selection has made this possible. However, one key factor to take into consideration is the age of the patient. Age should always be considered when dealing with the thought process of keeping teeth versus removing them, as we should always be thinking of the most conservative approach while not sacrificing the prosthetic lifespan of each restoration.

CASE REPORT
Diagnosis and Treatment Planning

A 27-year-old male presented to our office after a surfing accident that resulted in a severe fracture of his maxillary incisors (Figures 1 to 3). Clinical and radiographic examination revealed pulpal exposure of the maxillary right lateral incisor (tooth No. 7), indicating the need for root canal therapy. The considerations included the longevity of endodontically treated anterior teeth in a young patient, and also determining if posts would be a necessary part of the restorative treatment.2 With the large size of the fracture and little coronal tooth left, the pros and cons of preparing for a post pattern had to be considered. The maxillary right central incisor (tooth No. 8) was fractured coronally and presented with +2 mobility, indicating a fracture of the buccal plate. The maxillary left central incisor (tooth No. 9) showed a Class IV fracture on the mesial-incisal. There was a pulpal exposure with no mobility noted.

There are many questionable things that can happen in a trauma patient like this that can make creating a standard treatment plan difficult. Therefore, we refer to these to our patients as a fluid treatment plan. This means that the treatment plan may change throughout the course of treatment, depending on the circumstances.

Figure 1. Initial smile. Figure 2. Initial retracted.
Figure 3. Initial full-face photo.

With the buccal plate of bone fractured, we had to consider removing the maxillary right central incisor (tooth No. 8) and to find a solution that would satisfy the function and aesthetics of the clinical challenges as presented. The options available for single-tooth replacement in the anterior region include a fixed partial denture (bridge), a resin-bonded restoration, or a single-tooth implant. As a part of the decision-making process, it is necessary to know all the available options of treatment, the pros and cons of each treatment option, and how to proceed with the actual treatment protocol.

The resin-bonded restoration option would be suitable if the adjacent teeth were virgin (untreated) teeth. This type of restoration would be used more as a temporary solution if, for example, we were going to place an implant and could not temporize immediately. Since both adjacent teeth were going to need root canal therapy, a resin-bonded restoration was not the treatment option of choice in this case.

A fixed partial denture (FPD) would be another option.3 Both adjacent teeth needed root canal therapy and crowns, and an FPD could be used as either a temporary restoration or a permanent one. An FPD is usually an easier and more predictable option to gain superior aesthetics in the pontic site. Advances in modern all-ceramic materials also allow for restorations that exhibit excellent strength and great aesthetic outcomes. However, using 2 endodontically treated teeth as abutments on a 3-unit bridge will always place the abutment teeth under more pressure than single-unit crowns. So whenever possible, the author prefers to go into a single-tooth situation.

Figure 4. Preparation/shade photo. Figure 5. Initial provisionals.
Figure 6. Initial restorations. Figure 7. “Temporary” restorations during implant therapy (retracted).
Figure 8. Temporary restorations during implant therapy (smile). Figure 9. Three-month healing post-extraction and bone graft.
Figure 10. Three-month healing post-extraction and bone graft. Figure 11. Implant placement.
Figure 12. Connective tissue (CT) graft. Figure 13. Initial closure.
Figure 14. Need for pontic adjustment on the porcelain temporary fixed partial denture. Figure 15. Tissue healing post-CT graft.

A single-tooth implant would be the third option. Placement and restoration of anterior implants has become much more predictable, and site development has become easier.4 Predictable aesthetic results, especially in the anterior region, require proper preservation of the osseous and soft tissues surrounding the tooth being removed, as well as proper implant placement and prosthetic management. However, this is where the fluid treatment plan comes into play for the patient. To properly build the surrounding architecture and provisional to proper form and function may require multiple surgeries. There is also the key question of the type of provisional that is suitable for use within each patient’s lifestyle during the development process. A major advantage in a single-tooth implant is that one does not have to prepare the adjacent teeth. In this case, however, both adjacent teeth would ultimately become full-coverage crown preparations due to the trauma suffered. This was advantageous to us, knowing that we could make an FPD as a temporary during site development if we chose to place an implant. Using an FPD would allow us to alter the pontic site to create optimal gingival architecture if connective tissue (CT) grafts were needed. It also is predicable for 4 to 6 months for the patient’s lifestyle and should always be taken into consideration.

After completion of a thorough examination and all options explained to the patient, we opted to treat the anterior 4 maxillary incisiors (teeth Nos. 7 to 10) to restore his aesthetics and function.

Clinical Treatment
The patient was initially sent to an endodontist (Dr. Jason Deblinger) for root canal therapy on teeth Nos. 7 and 9. The patient returned immediately following the root canal therapy to begin temporization. The post patterns were prepared by the endodontist. Size one Flexi-Posts (Essential Dental Systems) were placed in teeth Nos. 7 and 9. After being properly fitted and treated, the canals were etched using 35% phosphoric acid (Ultra-Etch [Ultradent Products]) for 15 seconds, then rinsed and dried with paper points. OptiBond Solo Plus (Kerr) was coated inside the canals and around the coronal tooth structure air-dried and light-cured (Demi Plus curing light [Kerr]) for 10 seconds. A resin cement (RelyX Unicem [3M]) was injected into the post patterns and the posts were placed. Ti-Core Auto E (Essential Dental Systems) was then injected around the post and coronal tooth structure and light-cured, and allowed to set for 5 minutes.

Figure 16. Thickness of buccal tissue post-graft.
Figures 17 and 18. Anatomical implant provisionals (Luxatemp Ultra, shade A1 [DMG America]).

Teeth Nos. 7 and 9 were prepared for an FPD with a butt-joint margin design. Tooth No. 10 was minimally prepared for a porcelain laminate veneer. Tooth No. 8 had to be extracted and an implant eventually placed after site preparation, so the tooth was cut down to the gumline so the area could be temporized. A photo was taken with shade tabs next to the teeth to show the color of the prepared teeth (stump shade) to the laboratory team (Figure 4). A final impression was taken with heavy- and light-body polyether impression material (Impregum Soft [3M]), and a bite registration was taken using a vinyl polysiloxane (VPS) (Regisil [Dentsply Sirona]). A counter alginate impression (Jeltrate [Denstply Sirona]) was taken.

Provisional restorations were then fabricated using a direct mock-up technique using a the bis-acryl provisional material, Luxatemp Ultra (DMG America) and a flowable composite, LuxaFlow Ultra (DMG America), formulated specifically for use as an add-on resin for Luxatemp Ultra and other bis-acryl provisional materials.

The patient had stated that he wanted to maintain the character of his “old” teeth and did not want to look like he had 4 perfect teeth next to his natural dentition. Careful examination of the broken teeth he presented with, along with some photos that the patient brought into the office to share, allowed us to see the irregularities and recreate the form in the temporaries. The temporaries would be used as a blueprint to accurately communicate exactly what was desired in the restorations to our ceramist (Figure 5).

The patient was sent to a periodontist (Dr. Brian Chadroff) to extract tooth No. 8 and start to develop the site for the implant. The patient was also sent to the lab for a custom shade evaluation of his own natural dentition and instructed to return to our office in one week to put transitional restorations in.

Together with the patient and ceramist, we decided on an all-ceramic anterior bridge as a temporary restoration while the patient would go through the implant process to ensure the highest level of aesthetics as well as a high level of predictability. A single feldspathic porcelain laminate veneer was also placed on tooth No. 10. The restorations were checked on the model for accuracy before the patient was brought back to insert (Figure 6).

Approximately one week later, the patient was anesthetized, and the restorations were tried in for fit and accuracy with water. The lithium di­silicate (IPS e.max [Ivoclar Vivadent]) all-ceramic FPD was delivered using TempBond Clear (Kerr). After try-in, the e.max veneer was conditioned with silane (Ultradent Products), air-dried, coated with an unfilled resin (OptiBond FL [Kerr]), and then covered (protected from ambient light). The tooth was then cleaned of any debris and etched with 35% phosphoric acid (Ultra-Etch) for 15 seconds, rinsed with copious amounts of water, partially air-dried, and then blotted gently to avoid desiccation of the dentinal tubules. OptiBond Solo Plus was applied, air-thinned, and then light-cured for 10 seconds. LuxaFlow Ultra shade B1, used as the final cement, was applied to the tooth and the restoration was seated.5 Excess cement was cleaned away and then the e.max veneer was tack-cured apically with the curing light for 5 seconds. Cement was cleared interproximally, mesially, and distally then light-cured as well. Full light curing for 45 seconds, both from the facial and lingual directions, was then performed. The apical and lingual margins were adapted and then the occlusion was checked and adjusted as needed.

Figure 19. Healthy gingival architecture prior to final impression. Figure 20. Custom impression coping.
Figure 21. Final impression technique. Figure 22. Final restorations on model.
Figure 23. Custom abutment try-in. Figure 24. Final restorations (IPS e.max [Ivoclar Vivadent]).
Figure 25. Final smile.

The patient returned to the clinic for periodic evaluation. At this point, if there were a need to adapt the pontic site after the initial healing had occurred, it could be done (Figures 7 and 8). The patient was instructed to return to the surgeon in 3 months for implant placement. At that time, we would know if an additional CT graft was needed to obtain proper apical facial height in our final restoration.

After 3 months, the patient returned to the periodontist (Dr. Chadroff). At this point in the treatment, an additional CT graft was indicated. Some facial thickness of tissue had been lost (Figures 9 and 10). Simultaneously, a 3i Nanotite Certain (4.0 x 13.0 mm internal hex) implant was placed along with a demineralized freeze-dried bone allograft and a vicryl membrane. The FPD was placed in the patient’s mouth and the next day was evaluated to ensure that the pontic site was adequate and that there was no pressure on the implant (Figures 11 to 14). All pressure was relieved from the pontic site and the FPD was re-cemented using TempBond Clear. The patient was instructed to return to Dr. Chadroff’s office to uncover the implant in 5 months.

At the time of uncovery, the tissue had healed nicely, and adequate thickness was present to move forward with creating a final restoration (Figures 15 and 16). Immediately following the uncovering of the implant, the patient was sent to my office to temporize the implant and start to sculpt the soft tissue around the implant. An alginate (Jeltrate) impression of the upper arch was taken and the FPD removed.

Temporizing Implants
At the time of uncovery, the tissue around the implant was full but not sculpted. We opted to spend 4 weeks in a screw-retained temporary to let the tissue form around a properly contoured abutment.6 A 3i PreFormance temporary abutment (Zimmer Biomet) was placed and trimmed on the implant. Provisionals were created using the bis-acryl provisional material (Luxatemp Ultra, shade A1). The crowns on teeth Nos. 7 and 9 were cemented using TempBond Clear. The stent was then filled with Luxatemp Ultra and allowed to set. Once removed, the screw was accessed and unscrewed with the temporary crown locked onto the temporary abutment. This was then put on an analog and the apical aspect of the crown sculpted using LuxaFlow Ultra, shaped and tried in and out to confirm sulcular support. Once the shape was ideal with the proper apical tissue support, the provisional was polished and screwed into place (Figures 17 and 18). This was then placed back into the patient’s mouth and allowed to heal 4 weeks prior to final impression.

Final Impression
The patient was called back in for the final impression of teeth Nos. 7 to 10. We anesthetized the area and re-prepped the veneer of tooth No. 10. Both temporary crowns were removed and margins were prepared to the correct position. Finally, the temporary crown and abutment was unscrewed from the implant (Figure 19) and a temporary impression coping was fabricated. The crown was screwed into an analog, and a VPS bite registration material (Regisil) was injected all around the crown (Figure 20). The temporary crown was then unscrewed from the analog and an impression coping was screwed into place, leaving the negative of the apical form of the crown. Flowable composite was then injected into the negative around the impression coping and cured for 30 seconds (Figure 20). The impression coping was then unscrewed, tried, and screwed into the implant in the patient’s mouth (Figure 21). A final impression was taken with heavy- and light-body Impregum Soft polyether impression material, and a bite registration was taken with Regisil VPS bite registration paste (Denstply Sirona). A counter impression was taken with Jeltrate counter alginate. Shade photos of the preparations were also taken and communicated with the laboratory. The temporaries were put back in place and the case was sent to the laboratory with a detailed lab script, photos of the temporaries, model of the temporaries and prep shade diagnostic photos.

Final Restorations
We decided on all-ceramic restorations and a metal custom abutment for tooth No. 8 with porcelain baked on to match the preparation shade of the adjacent teeth. The restorations were checked for accuracy first on the model (Figure 22). The patient was then anesthetized in the area. The custom abutment was tried in first (Figure 23), then the crowns and veneers with water for accuracy. The restorations were then conditioned (as described previously), and the abutment was torqued to 20 Ncm. The access hole was covered with a cotton pellet and filled with a flowable composite and then light cured. The dentition was isolated (OptraGate [Ivoclar Vivadent]) and the bonding protocol was completed. The all-ceramic e.max crowns and veneers were cemented using a dual-cured resin cement (in a clear shade) (NX3 Dual-Cure [Kerr]). The implant crown was cemented using Premier Implant Cement (Premier Dental Products). The excess cement was removed, the occlusion checked, and the patient was dismissed. The patient was brought back at 2 weeks for a post-delivery evaluation (Figures 24 and 25).

CLOSING COMMENTS
Complex multidisciplinary cases, like the one presented herein, are always the most challenging for many reasons. First, when they are trauma cases, the mindset of the patient is much different when coming in for treatment. These patients did not come in to beautify their smiles; they are typically looking to just get their previous smile back. Second, the trauma itself will always present more “what if?”s because you are probably not going to be working in a stable environment. The results typically take longer and cannot be rushed to achieve true aesthetics and function. This means that the treatment team needs to figure out a way to handle the patient for the duration of the treatment required.

There are different choices with various protocols available to handle cases like the one presented, but no matter which treatment option is chosen, it is critical that the clinician understand and accommodate the patient in a manner that takes the patient’s life outside of the dental office into consideration. As a result, effort and planning must be put toward managing the treatment of a trauma patient such as this one throughout an extended time frame, requiring the need for transitional restorations that feel permanent and do not chip, stain, or fall out. And finally, when the clinician and laboratory team are creating restorations that need to blend naturally into an existing dentition, one always must be much more critical of the work to truly deliver an aesthetic success.

Acknowledgment
The author acknowledges that success is a result of great dental and laboratory teams and an understanding and cooperative patient. He would like to thank his periodontist Dr. Brian Chadroff (private practice, New York, NY), endodontist Dr. Jason Deblinger (private practice, New York, NY), Dr. Andi-Jean Miro (Rosenthal Apa Group, New York, NY), and Calvin Munn (Jason J. Kim Dental Aesthetics, Long Island, NY) for his ceramic artistry.


References

  1. Tikku AP, Chandra A, Bharti R. Are full cast crowns mandatory after endodontic treatment in posterior teeth? J Conserv Dent. 2010;13:246-248.
  2. Schwartz RS, Robbins JW. Post placement and restoration of endodontically treated teeth: a literature review. J Endod. 2004;30:289-301.
  3. Hebel K, Gajjar R, Hofstede T. Single-tooth replacement: bridge vs. implant-supported restoration. J Can Dent Assoc. 2000;66:435-438.
  4. Bichacho N, van Dooren E, Fradeani M, et al. Tissue management and prosthetic considerations with immediate implantation in the anterior maxilla. In: Schwartz-Arad D. Ridge Preservation and Immediate Implantation. London, England: Quintessence Publishing; 2012:105-120.
  5. Poss SD. Successful application of total-etch and self-etch techniques in adhesive dentistry. Inside Dentistry. 2011;7:80-81.
  6. Caudry S. Temporizing immediate implants: creating the foundation for long-term success. Oral Health. 2014;104:50.

Dr. Apa is a graduate of New York University College of Dentistry and maintains private practices in New York City and Dubai, UAE. He is a member of the American Academy of Cosmetic Dentistry (AACD), ADA, and AGD. He is on the editorial advisory board for the Journal of Implant and Advanced Clinical Dentistry and has been named a Leader in Continuing Education by Dentistry Today for many years. He was a recipient of the AACD’s 2007 Cosmetic Dentistry Award as well as the recipient of the American Academy of Hospitality Services Five-Star Diamond Award. He can be reached by calling (212) 794-9600 or by visiting his practice website at rosenthalgrp.com.

Disclosure: Dr. Apa reports no disclosures.

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