Developing Optimal Tissue Profiles With Implant-Level Provisional Restorations

Developing ideal papillae and sulcular levels surrounding multiple adjacent implants presents the ultimate aesthetic challenge for restorative dentists, even when meticulous surgical and restorative protocols are followed.1,2 Contoured provisional restorations placed on implants are effective tools for restorative dentists to direct the available volume of soft tissue to its most optimal levels before proceeding to definitive restorations.3-5 The provisional restoration will not stimulate growth of soft tissue; it is used to redirect a set volume of gingiva to establish optimal papillary and sulcular profiles.6 The restorative dentist must develop the 3-D shape of the provisional restoration from a relatively narrow and cylindrical implant into the triagonal form of an anterior tooth as the restoration emerges from the sulcus.

It is unlikely that full papilla height can be recaptured between adjacent implants with currently available techniques,7 but the provisional restoration allows the restorative dentist to maximize the volume of tissue that remains. The soft-tissue profile may ultimately be the same when using a provisional or a definitive prosthesis, but establishing it in the provisional stage provides a guide for the peri-implant tissue to form before the definitive restoration is made.8

As a critical means of communication between the dentist and laboratory technician, a provisional restoration on adjacent implants provides the technician with pre-established soft-tissue levels, which eliminates the ambiguities of predicting gingival form with the definitive prosthesis. The purpose of this article is to describe and demonstrate an effective chairside technique for the fabrication of a provisional prosthesis on adjacent implants to optimize soft tissue levels.

TECHNIQUE 
Matrix Formation

A 42-year-old female patient lost her maxillary central incisors and right lateral incisor from trauma. Unhappy with the discomfort and aesthetic compromise of the removable partial denture she had been wearing since that time, she sought treatment for a more definitive solution. Three implants were planned, predicated on the patient’s desire for individual crowns. The patient was advised that soft-tissue results may be less than ideal due to loss of osseous support and limitations of papilla regeneration between adjacent implants. The patient decided to accept this potential compromise in order to avoid a fixed partial denture on 2 implants.

Figure 1. A surgical guide directed optimum interimplant spacing for 3 missing maxillary incisor teeth. Figure 2. Compromised gingival levels lie apical to the interim removable partial denture that was worn during integration and soft-tissue healing.
Figure 3. Extension of the removable partial denture pontics to the residual ridge revealed disproportionate clinical crowns.

The implant surgeon replaced the maxillary central incisors with 2 Osseotite standard external hex implants with 4.1-mm diameter platforms and replaced the right lateral incisor with one Osseotite Micro-Miniplant with a 3.4-mm diameter platform (Implant Innovations). The restorative dentist provided the surgeon with a surgical guide to ensure that implant spacing was predicated on preservation of interproximal bone and soft tissue (Figure 1).9,10 The restorative dentist provided the patient with an interim removable partial denture to be worn during implant integration (Figures 2 and 3). Because the patient was satisfied with the tooth form and alignment of the interim prosthesis, a cast was made of this prosthesis in place. A vacuum-formed matrix was made on this cast. The matrix was trimmed just apical to the crowns of the teeth to be replaced and reduced proximally to include 2 teeth on either side of the intended provisional restoration. Alternatively, the matrix could have been made from an ideally contoured waxing of the replacement teeth.11

Selection and Preparation of Abutment Cylinders

Figure 4. Titanium temporary abutment cylinders were reduced and hand-tightened on the integrated implants.

Temporary abutment cylinders made of titanium alloy are effective, easy to prepare, and less costly than definitive abutments. Depending on implant angulation, provisional crowns on anterior implants can be temporarily cemented or screw-retained. In this patient example, screw access openings were positioned to allow for a screw-retained prosthesis. Titanium alloy temporary implant cylinders (Implant Innovations) designed for screw retention were selected. Healing abutments were sequentially removed, and appropriate temporary cylinders were hand-tightened onto the implants (Figure 4). The need for occlusal, gingival, palatal, and facial reduction was assessed, and the cylinders were prepared extraorally with separating disks on a straight handpiece. The temporary cylinders were reseated, the screws were hand-tightened again, and cotton was placed into the access openings. Adequate abutment preparation was verified by placing the clear, vacuum-formed matrix intraorally over the temporary cylinders. To allow retrieval of the temporary abutment cylinders, holes were drilled into the palatal surface of the matrix corresponding to the screw access openings.

Provisional Restoration Fabrication

Figure 5. The matrix was firmly seated and held in place for 90 seconds, then removed with the temporary cylinders. Figure 6. A void was left between the gingival extent of the provisional restoration and the subgingival margins of the temporary cylinders.
Figure 7. Flowable composite resin was injected into the voids and light-cured. The voids were filled, and the restoration was then ready for contouring.

An appropriate shade of EXACTA Temp Xtra bisacrylic resin (EXACTA Dental Products) was injected  and the matrix was completely seated over the temporary cylinders and held into place (Figure 5). As the material began to gel, an explorer was used to remove the cotton pellets that were placed into the temporary cylinders. This created access for an implant driver to remove the cylinders and the provisional restoration. After 90 seconds, the abutments were loosened, and the matrix, provisional restoration, and temporary cylinders were gently removed from the mouth as one unit. The restoration was allowed to cure for at least another 30 seconds before its separation from the matrix. Because the soft tissue quickly collapsed around the temporary abutment cylinders, a void remained between the gingival crest and the subgingival implant margins of the temporary abutment cylinders (Figure 6). EXACTA Flow flowable composite resin (EXACTA Dental Products) was then injected to fill the voids, and the resin was cured with a high-intensity light (Figure 7).

Provisional Restoration Contouring and Finishing

Figure 8. Gingival levels were scribed with an artist’s pencil, and additional flowable composite resin was added to deficient contours.

To achieve the objective of optimal soft-tissue levels, the gingival and subgingival forms of the provisional restoration were subtly contoured. The provisional restoration was seated to observe the adaptation of the surrounding gingiva. A marking pencil or indelible pen was used to denote the location of the gingival margins on the provisional restoration (Figure 8). Flowable composite resin was selectively added or reduced appropriately to redirect papillae and sulcular levels. Because carbide burs are minimally effective and dull quickly on bisacryl resin, impregnated rubber wheels and disks were used for contouring. Thin diamond disks were used to delineate proximal contact areas to create the perception of separate teeth. This contouring process was continued until the soft-tissue profile of the available gingival tissue was optimized.12,13

Figure 9. Following try-in and modifications, the provisional restoration was polished and glazed with an unfilled, light-cured resin prior to seating. Figure 10. The provisional implant restoration was seated, and screws were tightened to specified torque.
Figure 11. Access openings were sealed with cotton pellets and dental stopping. Figure 12. From the facial aspect, the provisional restoration helped in re-creating sulcular form around the implant restorations.
Figure 13. Pleased with the aesthetic outcome of the provisional restoration, the patient gave the dentist approval for using this as a matrix for definitive reconstruction.

After final polishing and coating with EXACTA Glaze (EXACTA Dental Products), the provisional restoration was reseated (Figures 9 through 13). Some blanching of the gingiva occurred, which is acceptable and expected upon initial seating of the provisional prosthesis. Screws were tightened to specified torque using a torque device, and access openings were filled with cotton and dental stopping. Over a period of several weeks to months, the provisional restoration was observed and further modified to fine-tune the contours. Following tissue maturation, the restorative dentist and the patient assessed the aesthetic results and observed the gingival form prior to progressing to the final crowns.

Creating and Seating Definitive Restorations

Figure 14. Although not reformed to the same heights found around natural teeth, soft-tissue levels developed using the provisional restoration demonstrated parabolic sulcular form. Figure 15. In the occlusal plane, the sulcular outline developed by the provisional restoration simulated the trigonal shape observed around maxillary incisors.
Figure 16. For maximum positional accuracy, direct implant impression copings were splinted with dental tape and acrylic resin. Figure 17. An impression was made using polyvinyl siloxane impression material in a stock tray.
Figure 18. Using tooth and soft-tissue contours developed with the provisional restoration, ceramic implant abutments and ceramic crowns were made. Figure 19. Each ceramic abutment and crown was atraumatically seated in a sulcus previously established by the provisional restoration.
Figure 20. Normal tooth contours, colors, and gingival architecture contributed to a pleasing smile.

Once the soft tissue reached full maturity and the restorative dentist and patient were satisfied with the aesthetic results, the approved provisional restoration provided an invaluable script for the laboratory technician to follow.14 In this patient example, the restorative dentist provided the laboratory with a cast of the provisional restoration. Digital images of the 3-D form of the soft tissue with and without the provisional restoration in place guided the technician to replicate these contours when creating the definitive implant abutments and crowns (Figures 14 and 15). An implant-level impression was made using splinted pickup impression copings (Implant Innovations) and FRESH VPS impression material (EXACTA Dental Products) in a stock tray (Figures 16 and 17). The ceramist created individual ceramic abutments and crowns, predicated on the provisional restoration (Figure 18). Each crown was atraumatically seated in its sulcus already established by the provisional restoration (Figures 13 and 14), instead of attempting to force the restoration into a small cylindrical space developed only by a healing abutment. With the patient’s expressed acceptance of the definitive prostheses, the abutment screws were tightened to specified torque, and the ceramic crowns were cemented (Figures 19 and 20).

CONCLUSION

The provisional phase is the most prolonged and arguably the most crucial stage of restorative implant treatment. When working in the demanding arena of the aesthetic zone, an implant-level provisional restoration plays an essential role in the development and assessment of tooth contours and soft-tissue levels. Naturally appearing provisional restorations are part of the transformation of implant dentistry from a secure functional alternative to an option that provides the potential for optimal aesthetic results.


References

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2. Buser D, Martin W, Belser UC. Optimizing esthetics for implant restorations in the anterior maxilla: anatomic and surgical considerations. Int J Oral Maxillofac Implants. 2004;19(suppl):43-61.

3. Touati B. Improving aesthetics of implant-supported restorations. Pract Periodontics Aesthet Dent. 1995;7:81-93.

4. Tarnow DP, Eskow RN. Preservation of implant esthetics: soft tissue and restorative considerations. J Esthet Dent. 1996;8:12-19.

5. Chee WW, Donovan T. Use of provisional restorations to enhance soft-tissue contours for implant restorations. Compend Contin Educ Dent. 1998;19:481-489.

6. Testori T, Bianchi F, Del Fabbro M, et al. Implant aesthetic score for evaluating the outcome: immediate loading in the aesthetic zone. Pract Proced Aesthet Dent. 2005;17:123-130.

7. Tarnow D, Elian N, Fletcher P, et al. Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants. J Periodontol. 2003;74:1785-1788.

8. Touati B, Guez G, Saadoun A. Aesthetic soft tissue integration and optimized emergence profile: provisionalization and customized impression coping. Pract Periodontics Aesthet Dent. 1999;11:305-314.

9. Tarnow DP, Cho SC, Wallace SS. The effect of inter-implant distance on the height of inter-implant bone crest. J Periodontol. 2000;71:546-549.

10. Grunder U, Gracis S, Capelli M. Influence of the 3-D bone-to-implant relationship on esthetics. Int J Periodontics Restorative Dent. 2005;25:113-119.

11. Dieterich J. Implant crowns with a natural emergence profile. Dental Dialogue. 2003;3:8-15.

12. Potashnick SR. Soft tissue modeling for the esthetic single-tooth implant restoration. J Esthet Dent. 1998;10:121-131.

13. Touati B. The double guidance concept. Pract Periodontics Aesthet Dent. 1997;9:1089-1094.

14. Lewis S, Parel S, Faulkner R. Provisional implant-supported fixed restorations. Int J Oral Maxillofac Implants. 1995;10:319-325.



Dr. Priest lectures nationally and abroad while maintaining a full-time prosthodontic practice in Atlanta devoted to aesthetic, advanced restorative, and implant dentistry. He is a regular contributor to restorative and implant journals, a diplomate of the American Board of Prosthodontics, a fellow of the American College of Prosthodontists, and a 2005 inductee into the International College of Dentists. Dr. Priest has been a teacher of implant and aesthetic dentistry for 19 years, remaining in the forefront of technology and education. He can be reached at (404) 377-9680, This e-mail address is being protected from spambots. You need JavaScript enabled to view it , or by visiting priestprospro.com.

Disclosure: Dr. Priest is a consultant for and does have a financial interest in EXACTA Dental Products and 3i Implant Innovations.