Guided Peri-Implant Autogenous Soft-Tissue Grafting: A Case Report
This case report presents a proof of concept for a guided free gingival graft around a dental implant. A 65-year-old man presented to replace teeth Nos. 30 and 31. Once the osseointegration of the 2 implants placed by guided surgery had been achieved, a free gingival graft was indicated. The surgical planning of this graft was performed using cone-beam computerized tomography and arch digital scanning already used for implant placement. The greater palatine foramen and gutter were radiologically located to protect their arterial content. Two surgical guides were designed, one for the palatal donor site and one for the recipient site. The first one served both as an incision guide and as a postoperative protective plate. The procedure was free of adverse events. At the 1-year recall, the average gain in keratinized tissue width was 2.5 mm. This guided surgery could be used in a patient with insufficient amount of keratinized tissue around a posterior implant. For the first time, this procedure makes it possible to (1) anticipate, (2) accelerate, and (3) secure the surgical intervention. This technique can improve the practitioner's operative comfort and potentially the outcomes of free gingival grafts. Further research and clinical studies are needed to validate this protocol and to assess its long-term impact on peri-implant health.
Clinical situation after the 3 months of implants osseointegration. (a, b) Vestibular and occlusal view of implants. The keratinized tissue defect was visible: between 0.25 and 1 mm of keratinized tissue in the No. 30 site and less than 0.5 mm in the No. 47 site. (c) Occlusal view of the maxilla with a deep palate and marked bunoid papillae extending to the first premolar.
Planning of the recipient and donor sites. (a) The practitioner drew the contours of the future mandibular recipient bed and specified to the info-prosthetist the optimal zone for palatal graft harvesting. (b) Delineation of the course of the greater palatine artery. (c) The external surface of the palatal mucosa (orange line) and the contours of the greater palatine gutter (red circle) have been positioned 3-dimensionally in relation to the matching of the cone-beam computerized tomography and digital model. The thickness of the entire palatal mucosa (light green line, 5.55 mm) or the distance between the great palatine artery and the gingival collars (dark green line, 20.05 mm) could then be measured.
Design of the mandibular and maxillary surgical guides. (a, b) The complete mandibular surgical guide was designed, and then the digital pattern (in pink) was individualized and (c) subtracted from the guide. (d, e) For the maxillary surgical guide, the digital pattern was printed and clinically positioned to the harvesting site. Its contours were marked using a flowable composite before being scanned. (f) The maxillary surgical guide with a window corresponding to the harvesting site was then designed accordingly.
Preparation of the mandibular recipient site. (a) Peri-implant mucogingival surgery guide. (b) Site after local anesthesia objectivizing the defect of the keratinized tissue. (c) Surgical guide in position. The incision was guided by the contours of its window. (d) After removal of the guide, a partial-thickness flap was reflected and fibrous or muscular insertions dissected.
Preparation of the maxillary donor site. (a) Maxillary surgical guide in position. (b) Harvesting of the graft in partial thickness (c) Verification of the dimensions of the graft by comparing it to the digital pattern. (d) A palatal protection plate was made by reassembling the digital pattern and the surgical guide with flowable composite.
Clinical, radiographic, and digital assessment after guided free gingival grafting. (a) On day 0, the graft was placed and immobilized at the recipient site with sutures. (b) At 1.5 months, healing was satisfactory with a band of 1.75 mm to 4 mm of keratinized tissue around the implant healing caps. (c) At 1 year, the keratinized tissue band was well maintained, and (d) periapical radiograph showed a stable peri-implant bone height. (e) Superimposition of pregraft and postgraft digital impressions at 1 year showed a gain of 1 mm of keratinized tissue thickness (f) and a keratinized tissue thickness close to 2.7 mm.
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