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JOMI on CD-ROM, 1996 Jan (46-54 ): Flap Designs for Minimization of Recession Adja Copyrights 1997 Quinte

Flap Designs for Minimization of Recession Adjacent to Maxillary Anterior Implant Sites: A Clinical Study William Becker, DDS/Burton E. Becker, DDS

The purpose of this study is to present new flap designs for the prevention of postoperative gingival recession adjacent to maxillary anterior sites that received dental implants. Nine patients received 10 implants in the maxillary anterior region. Gingival morphotypes and smile lines were evaluated prior to implant placement. Gingival probing depths, clinical attachment levels, and recession were recorded at teeth adjacent to implant sites at the initial exam and 3 months after implant restoration. A minimum of 5 mm of crestal bone width was required for implant placement. The labial flaps for healed ridges and implants placed into sockets were extended to or within 1 to 3 mm beyond the alveolar crest. In two sites, transfer of the implant relationships was made to provide the patients with provisional restorations at the time of second-stage surgery. Four patients had implants placed at the time of tooth removal. In these patients, expanded polytetrafluoroethylene barrier membranes were modified, removing the outer rim of material. The inner portion of the material was placed over the implant and the flaps were sutured, leaving the center part of the material exposed. The purpose of using the barrier in this manner was to protect the clot and subsequent granulation tissue formation during the first 2 weeks of healing. The material was removed 2 weeks after surgery. Six implants were placed into edentulous sites. At second stage surgery, flaps were reflected to the alveolar crest, thereby minimizing the potential for gingival recession. Provisional restorations placed at the time of implant uncovering appeared to support the repositioned gingiva. Changes in probing depth, clinical attachment levels, and recession were not statistically or clinically significant. Results of this pilot project suggest that flap designs minimized recession at teeth next to implant sites.(INT J ORAL MAXILLOFAC IMPLANTS 1996;11:4654)Key words: barrier membrane, flap design, gingival morphotype, gingival recession, smile line

Replacement of single teeth by dental implants is a viable treatment option. The predictability of single-tooth endosseous implants to function for up to 3 years with a 98.5% success rate has been reported by Jemt and Petersen.1 The successful application of single-tooth implants has increased patient demands for improved esthetics in the maxillary anterior region of the mouth. Conventional implant flap management has the risk of resulting in gingival recession around teeth adjacent to


the edentulous ridge. To avoid recession, implant surgeons must be aware of gingival anatomy of the adjacent teeth. Placement of implants immediately after tooth extraction may result in gingival recession on adjacent teeth.2,3 The use of pedicle flaps from adjacent teeth to cover implants placed immediately after tooth extraction can be successfully used for posterior implant sites. However, the use of this technique in the maxillary anterior region has the risk of resulting in gingival recession at the donor site.

Ochsenbein and Ross4 described gingival contours as flat or pronounced scalloped, with the gingiva reflecting the underlying osseous topography. A flat periodontium is usually thick, with the gingival margins being at or coronal to the cementoenamel junctions. A pronounced scalloped periodontium is usually thin, with the gingival margin being at the cementoenamel junction. Patients with a thin, scalloped periodontium may be susceptible to gingival recession. Weisgold5 related the observations of the previous authors to crown form and tooth preparation. He noted that recession generally occurs in patients with a thin, scalloped periodontium. Olson and coworkers6 recently studied gingival morphotypes in adolescents. Patients with a thin, scalloped periodontium had a narrower zone of keratinized gingiva when compared with subjects with a flat periodontium. Furthermore, attachment loss was greater in the group that had a scalloped periodontium. As a result of clinical observation and information from the previously cited studies, an understanding of gingival anatomy and bone morphology is required prior to implant placement and particularly prior to placement of single-tooth implants in the maxillary anterior regions.

The purpose of this study is to describe flap designs that may reduce or eliminate gingival recession on teeth adjacent to sites receiving endosseous implants. The effectiveness of the procedures were evaluated in terms of changes in probing depth, probing attachment levels, and recession. Furthermore, the effectiveness of the techniques to promote formation of gingival papillae adjacent to the implants was evaluated.

Materials and Methods To date, 25 consecutive patients have been treated in this study. This preliminary report is based on nine consecutively treated patients who received 10 maxillary single-tooth implants. The patients were referred for evaluation for either immediate tooth removal and implant placement in the maxillary anterior region or single-implant placement in the maxillary anterior region.

Diagnosis. All patients had complete periodontal and dental examinations and were in good health. Clinical attachment levels were measured on the teeth adjacent to the tooth being considered for removal or next to edentulous areas. These measurements were made with a standardized Michigan O periodontal probe with Williams markings periodontal probe (Hu-Friedy, Chicago). The measurements were made from the free gingival margin to the base of the sulcus (probing depth)


and from the cementoenamel junction or crown margin to the base of the sulcus (probing attachment level). These measurements were taken at the initial examination and 3 months after the implant crown restorations were placed.

The gingival tissues were classified as being thin with a pronounced scallop, or thick with a flat gingival profile, or moderately thick. Smile lines were classified according to Tjan and Miller.7 A high lip line resulted in complete exposure of the teeth and gingival tissues during smiling. An average smile line revealed 75% to 100% of the maxillary anterior teeth and the interproximal papilla. A low smile revealed less than 75% of the teeth.

Periapical radiographs were taken of the surgical area (Fig 1a). Bone quality, bone quantity, and the distance from the alveolar crest to the floor of the nose were determined from these radiographs. The radiographs were also used to rule out periapical pathology and to access bone levels adjacent to the teeth. Linear tomographs were taken to determine buccal-palatal bone width and height. A minimum of 5 mm of bone width at the alveolar crest and 10 mm of bone height was required for inclusion in the treatment group. Tomographs were used to determine the presence of bone concavities, which could interfere with implant placement. Diagnostic casts were obtained to evaluate occlusal relationships and for the fabrication of surgical and transfer coping templates.

Surgical Technique. Immediate Implant Placement. All patients were given detailed oral and written explanations of the procedures that were to be performed, and each signed treatment consent forms. The patients began an established antibiotic regimen 2 hours prior to surgery (2 g of penicillin or erythromycin 2 hours presurgery and 1 g per day thereafter for 7 days).8 The patients were premedicated with intravenous medications, and a local anesthetic agent was administered (xylocaine 1:100,000 epinephrine, Astra, Rutherford, NJ). The gingival papillae were released from the adjacent tissues with a 15C scalpel blade, and the labial flap was extended to or slightly beyond the alveolar crest. They were released from the adjacent teeth on the palatal aspect, creating a palatal envelope flap. An alternative method involves creating two parallel vertical incisions on the palatal aspect and reflecting a small full-thickness palatal flap. A full-thickness palatal flap can then be reflected. A Molt C-2 elevator (Hu- Friedy) was used to luxate the teeth. Once the tooth was loosened, it was removed with forceps. The socket was debrided with periodontal curettes and files. A surgical template was seated onto the adjacent teeth. The sites were prepared according to Adell et al.9 During drilling, light finger pressure was applied over the buccal aspect of the surgical site. The purpose for this was to feel for possible labial plate perforations. The decision to tap the bone was made on the basis of bone quality. Bone quality was arbitrarily determined during drilling. Only dense bone was tapped. When tapping was performed, only the coronal one half of the socket was tapped. Standard 3.75-mm implants (Nobelpharma USA, Chicago) were placed into the prepared sites under a constant


stream of chilled sterile saline and were immobile after placement. The head of the implant was placed parallel to the incisal edges of the adjacent teeth and was a minimum of 2 mm below the alveolar crest10 (Fig 1b). At the coronal bone-to-implant aspect, there were gaps between the implant and surrounding bone. These sites were not grafted.

In two patients, implant transfer templates were used to transfer the implant position to a cast. The casts were used to fabricate provisional restorations.11 A cover screw was then secured to the implant head.

Oval 6 or Oval 9 barrier membranes (WL Gore, Flagstaff, AZ) were trimmed, removing the outer nonocclusive material. The purpose of using the barrier was to protect the blood clot surrounding the implant and to protect the granulation tissue during the first 2 weeks of wound healing. The barriers were tucked under the labial and palatal flap margins. Interproximal expanded polytetrafluoroethylene (e-PTFE) sutures (WL Gore) were used to suture the interdental areas, leaving the occlusive inner portion of the barrier membrane exposed (Fig 1c). Light gauze pressure and ice were applied to the surgical area. At the second postoperative week, the sutures and barriers were removed and the provisional restoration was adjusted to eliminate pressure on the ridge tissues.

Second-Stage Surgery. The area of implant placement was photographed and anesthetized (Fig 2a). A horizontal incision was made on the palatal aspect of the ridge, extending from the line angles of the two adjacent teeth (Fig 2b). A USC gingivectomy knife (Hu-Friedy) was used to dissect the tissue from the underlying bone and to reflect the tissue to the labial alveolar crest (Fig 2c). The cover screw was removed, the implant hex head was debrided, and either a healing abutment or a provisional restoration was placed onto the implant head (Figs 2d and 2e). A radiograph was taken to verify complete seating of the provisional or healing abutments on the implant hex head. The tissues on the labial aspect were placed slightly coronal to the gingival margins on the adjacent teeth, and interdental sutures were placed. The sutures were removed 1 week later. Final restorations were placed 8 to 10 weeks after the second-stage procedure (Figs 2f and 2g).

Flap Design for Maxillary Anterior Region: Tooth Is Missing. The diagnostic steps discussed above were performed in the same manner when the tooth was missing. Figure 3a shows the linear tomograph taken during the planning stage of treatment. The tomograph revealed a minimum of 5 mm of labial-lingual bone width. The patient had a moderately thick periodontium (Fig 3b). The surgical technique to achieve minimal recession involved the reflection of a curtain of tissue from the edentulous ridge, being careful not to extend the flap more than a few millimeters beyond the alveolar crest (Fig 3c). Implant placement followed the standard protocol for placement into edentulous ridges. Two interrupted sutures were placed at the line angle (Fig 3d). Figures 3e and 3f demonstrate the clinical and radiographic appearance 1 year after loading.


The relationship of the interproximal gingival tissues was assessed from the clinical photographs. The existence of a dark triangle between the implant restoration and the adjacent tooth was considered an incomplete soft tissue fill of the interdental space.

Statistical Evaluation. The paired Student t test for a small sample size was used to compare differences between means for teeth adjacent to the implant. Comparisons of changes between examinations were made for probing depth, clinical attachment levels, and recession.

Results Of the nine treated patients (10 implants), two patients were classified as having a thin, scalloped periodontium, six had a moderately thick gingival profile, and one patient had a flat, thick gingival profile. Two patients had high lip lines, four patients were classified as having average lip lines, and three patients had low lip lines (Table 1).

Table 2 presents the data for probing depth, probing attachment level, and recession for teeth adjacent to sites that received implants. Diffferences in probing depths, clinical attachment levels, and recession were statistically and clinically insignificant. At the initial examination, the mean gingival margin location for teeth adjacent to implant sites ranged from 2.04 mm to 1.89 mm coronal to the cementoenamel junctions. Three months after implant restoration, the mean gingival margin location on teeth adjacent to the implants ranged from 1.97 mm to 0.67 mm. These means indicate that there was clinically insignificant postoperative gingival recession and that the gingival margins adjacent to the teeth remained coronal to the cementoenamel junctions postsurgery.

Four implants were augmented with e-PTFE barrier membranes for the purpose of promoting gingival coverage of the exposed implant head. At the second stage, the implants were completely covered by gingival tissue, and bone had filled the small gaps between the implants and surrounding bone.

Of the 10 implants, two received provisional restorations at the second-stage surgery. One patient received the final restoration at the second-stage visit. The remaining seven implants had healing abutments placed at the second stage and received provisional restorations within 3 to 6 weeks following the second-stage procedures.

Table 3 describes the relationship of the interproximal gingival tissues to the implant-retained crowns. Gingiva filled the interimplant embrasures at six of the 10 implant sites. The patients were examined 1 year after implant loading and radiographs were taken. Figures 2f and 3e were taken 1 year after loading. It can be seen that the gingival tissues adjacent to the implants are even with the adjacent teeth. There was no loss of implants at the 1 year evaluation, and the location of the


gingival margins in relation to the implant restorations and adjacent teeth were unchanged from the 3-month examinations.

Discussion The 10 implants reported in this pilot project have been loaded for more than 1 year and have demonstrated no clinically significant evidence of gingival recession on the teeth adjacent to the implants. Changes between probing depth and clinical attachment levels were statistically and clinically insignificant. These preliminary results for a limited sample size provide data that indicate that the flap designs were effective in eliminating postoperative gingival recession on teeth next to the implant sites. Prior to surgery, the patients gingival profile and smile lines were evaluated to attempt to identify patients who could be susceptible to gingival recession. The surgical technique necessary to predictably reduce gingival recession in patients with varying gingival morphotypes requires a minimum of 5 mm of bone width at the alveolar crest and a minimum of 10 mm of bone height. The labial flaps were not extended more than 1 to 3 mm beyond the alveolar crest. Use of conservative flap designs may have eliminated postoperative gingival recession on the adjacent teeth. This was noted in the clinical documentation and by comparing the preoperative and postoperative clinical measurements.

At the initial exam, the average gingival margin location for teeth adjacent to the implant sites ranged from 1.89 mm to 2.04 mm coronal to the cementoenamel junction. At the second-stage surgery, the gingival margins remained coronal to the cementoenamel junctions. Gingival recession frequently occurs after periodontal surgery. Isidor et al12 reported an average of 2.5 mm of recession after periodontal surgery and 1.8 mm after scaling and root planing. At 6 months and 1 year postsurgery, Becker and coworkers13 reported significant recession after treatment of 4- to 6-mm probing depths with osseous surgery and modified Widman procedures. These recession changes ranged from 1.25 mm for osseous surgery and 1.05 mm for the modified Widman procedures. These types of procedures involved flap elevation to or beyond the mucogingival junction. In the present study, labial flaps were reflected to the alveolar crest, and these types of incisions may have contributed to the insignificant changes in gingival margin positions on the teeth adjacent to the implants.

Lazzara2 reported on the use of e-PTFE barrier membranes for the promotion of bone adjacent to immediately placed implants. The barrier membranes were not covered by the flaps and were frequently removed several weeks after placement. At second-stage surgery, bone was clinically evident around the previously augmented implants. The e-PTFE barrier membranes were used to protect the clot and to promote undisturbed epithelialization over the implants. The biologic rationale for this procedure has not been evaluated in a controlled environment but appears to be clinically effective. At second-stage surgery, the small bony gaps that were initially present adjacent to the implants had filled in with bone. This observation supports

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the earlier report of Lazzara2 and may indicate that retention of barrier membranes for the entire healing period may not be necessary. Simeon et al14 has recently reported the results of exposing the inner portion of e- PTFE barrier membranes to bacterial contamination. Scanning electron microscopy demonstrated that at 1 week, the inner part of the e-PTFE barriers is totally occlusive to bacterial penetration. Landsberg and Bichacho15 have recommended covering extractions sockets that received immediate implants with small free gingival grafts. One of the disadvantages of this technique is the necessity to obtain the gingival graft from a second surgical site. Preliminary evaluation of this procedure indicates that it produces acceptable esthetic results.

Fabrication of esthetic implant-supported crown restorations in the maxillary anterior region is a demanding procedure. The surgeon, the restorative dentist, and the laboratory technician must attempt to create gingival tissue between the implant and the adjacent tooth. Creating an illusion of a papilla within the interproximal space requires expanding the gingival cuff adjacent to the implant and overcontouring the final restoration to support the laterally positioned tissue. To date, there are no data relating to the predictability of these procedures. In this study, the illusion of an interproximal papilla was created in five of the six sites that initially had moderately thick tissues with moderate gingival scallop.

The profession has become obsessed with eliminating small dark spaces between implants and adjacent teeth. Casual observation of tooth-supported fixed partial dentures in the maxillary anterior region frequently reveals small, dark, triangular interdental spaces. In adults, in many instances this appears natural. By displacing the gingival tissues adjacent to implants laterally and placing overcontoured restorations into the sulcus, we may be creating hygiene and other, as yet undetermined, peri-implant problems.

There are differences of opinion relating to implant placement in the maxillary anterior region. Shanaman16 placed implants in labial positions to achieve an optimal esthetic result. Placement of implants in labial positions frequently resulted in bony dehiscences of the labial plate. These defects were grafted with demineralized freeze-dried bone and barrier membranes. Saadoun et al17 suggested that the long axis of a single-tooth implant approximates the emergence profile of a single tooth. This position places the head of the implant in a labial position and frequently results in defects that require grafting and barrier augmentation. Gelb and Lazzara18 recently related implant placement to the amount of remaining bone. They suggested that angled abutments and copings are frequently required to correct implant emergence profiles. In this study, the shape of the bone in the maxillary anterior region dictated the emergence angle of the implant. The head of the implant was parallel to the incisal edges of the adjacent teeth, while the axis of the implant body was inclined palatally. Placement of the implants in this position did not compromise the labial plate, and all implants were restored with standard prosthetic components


(CeraOne, Nobel pharma). One of the disadvantages of utilizing minimal flap designs is the inability to determine when bone fenestrations occur during implant site preparation. The frequency of labial plate fenestration with the flap designs presented in our study are unknown.

Utilization of templates to transfer implant relationships to working casts provided an effective method-for providing provisional restorations at the second-stage surgery.11 This method, together with retention and careful positioning of the retained keratinized gingiva at the second stage, may have helped eliminate gingival recession adjacent to the implant sites. The provisional restorations appeared to support the repositioned gingival tissues.

Conclusion The short-term results of using flap designs described in this study suggest that postoperative gingival recession at implant sites and on adjacent teeth can be significantly minimized. The use of the inner portion of the e-PTFE barriers may have protected the clot over the implant, resulting in undisturbed wound epithelialization. Placement of provisional restorations at second-stage surgery may support the newly positioned gingival margins and contribute to maintenance of the gingival position in relation to the adjacent teeth. Acknowledgments

The authors gratefully thank Drs Clifford Ochsenbein, Arnold Weisgold, and Patrick Henry for their advice and encouragement during the preparation of this report. Many of the ideas expressed in this report were developed with the North American Periodontal Study Group.


1. Jemt T, Petersen P. A 3 year follow-up study of single implant treatment. J Dent 1993;21:203208.

2. Lazzara R. Immediate implant placement into extraction sites: Surgical and restorative advantages. Int J Periodont Rest Dent 1989;9:333343.

3. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: Surgical techniques and case reports. Int J Periodont Rest Dent 1990;10:377391.

4. Ochsenbein C, Ross S. A reevaluation of osseous surgery. In: Dental Clinics of North America. Philadelphia, PA: Saunders, 1969:87102.

5. Weisgold A. Contours of the full crown restoration. Alpha Omegan 1977;10:7789. 6. Olson M, Lindhe J, Marinello CP. On the relationship between crown form and

clinical features of the gingiva in adolescents. J Clin Periodontol 1973;20:570577.

7. Tjan AHL, Miller GD. Some esthetic factors in a smile. J Prosthet Dent 1985;51:2428.

8. Classen DC, Scott RE, Restotnik SL, Horn SD. The timing of prophylactic administration of antibiotics and the risk of surgical-wound infection. New Eng J Med 1992;326(5):281286.

9. Adell R, Lekholm U, Rocker B, Brnemark P-I. A 15 year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg 1981;10:387416.

10. Parel S, Sullivan D. Esthetics and Osseointegration. Guidelines for Optimal Fixture Placement. An Osseointegrated Seminars Inc Publication, 1989;1928.

11. Riser GM, Dornbush JR, Cohen R. Initiating restorative procedures at the first-stage implant surgery with a positional index: A case report. Int J Periodont Rest Dent 1992;12:279293.

12. Isidor F, Karring T, Attstgrom R. The effect of root planing as compared to that of surgical treatment. J Clin Periodontol 1984;11:669673.

13. Becker W, Becker BE, Ochsenbein C, Kerry G, Caffesse R, Morrison ED, Prichard J. A longitudinal study comparing scaling, osseous surgery and modified Widman procedures. Results after one year. J Periodontol 1988;59:351365.

14. Simeon M, Baldoni M, Rossi P, Zaffe D. A comparative study of the effectiveness of e-PTFE membranes with and without early exposure during the healing period. Int J Periodont Rest Dent 1994;14:167180.

15. Landsberg CJ, Bichacho N. A modified surgical/prosthetic approach for optimal


single implant supported crown. Part IThe socket seal surgery. Pract Periodontics Aesthet Dent 1994;6(2):1117.

16. Shanaman RH. The use of guided tissue regeneration to facilitate ideal prosthetic placement of implants. Int J Periodont Rest Dent 1992;12;257265.

17. Saadoun AP, Sullivan DY, Krischek M, Gall M. Single tooth implant management for success. Pract Periodontics Aesthet Dent 1994;6(3);7380.

18. Gelb DA, Lazzara RJ. Hierarchy of objectives in implant placement to maximize esthetics: Use of pre-angled abutments. Int J Periodont Rest Dent 1993;13;277287.


Fig. 1a Radiograph demonstrating a crown fracture of the maxillary right central incisor.

Fig. 1b The socket is debrided with periodontal curettes and files, and the labial and palatal flap margins are extended slightly beyond the alveolar crest. A 3.75-mm implant is placed into the extraction socket and the head of the implant is slightly below the alveolar crest. Note the bone defect on the labial, mesial, and distal implant aspects.


Fig. 1c The inner portion of an e-PTFE barrier is placed beneath the buccal and palatal flap margins. The sutures and barrier are removed 2 weeks after surgery.

Fig. 2a Six-month postsurgery evaluation. Note complete soft tissue healing over edentulous ridge.

Fig. 2b A USC periodontal knife is


used to reflect the ridge tissue toward the labial crest.

Fig. 2c The ridge tissue is reflected to the labial alveolar crest, and the implant head is exposed.

Fig. 2d A provisional restoration is placed, and the flap margins are positioned and sutured slightly coronal to the adjacent teeth.

Fig. 2e A provisional restoration was


placed at the time of the second-stage surgery.

Figs2f and 2g One-year evaluation of implant and soft tissue health. Note absence of recession on adjacent teeth. (Restorative dentistry, John Doerr, DDS.)

Fig. 3a A linear tomograph of the left edentulous lateral incisor region. There is 5 mm of labial-palatal width at the crest, and this dimension broadens superiorly.


Fig. 3b Preoperative view. Patient has moderately thick gingiva and a flat gingival profile. The smile line reveals all of the anterior teeth and the gingival papilla.

Fig. 3c A flap is raised to the labial aspect and is extended slightly beyond the alveolar crest. A 3.75-mm Nobelpharma implant has been placed into the prepared site. The head of the implant is located slightly apical to the alveolar crest.


Fig. 3d The flap margins are closed with interrupted sutures.

Fig. 3e One-year follow-up of implant and gingival tissues. Note absence of recession on adjacent teeth. (Restorative dentistry, Kent Banta, DDS.)


Fig. 3f Radiograph at 1-year implant evaluation visit.

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