Simultaneous placement of an interpositional free gingival graft with nonsubmerged implant placement
A 50-year-old female patient presented to the Department of Periodontology at Yonsei University Dental Hospital, Seoul, Korea, complaining of partial edentulism in the right mandible. The patient had no contributing medical history. The mandibular right second premolar and molars had been extracted 10 years previously, and she had been wearing a removable partial denture.\nThe posterior molar site of the edentulous mandible presented a thin band (approximately 2 mm) of keratinized tissue on the ridge crest and inadequate vestibular depth (). The treatment plan included the placement of three nonsubmerged implants in the positions of the mandibular right second premolar, first molar, and second molar. In addition, simultaneous interpositional free gingival grafting was planned in the molar area to increase the amount of keratinized tissue.\nThe protocol was reviewed and approved by the Yonsei University Institutional Review Board. The patient provided written informed consent before the onset of the surgery.\nA horizontal incision was made on the ridge crest starting from the distal gingiva of the first premolar and extending to the posterior area (). The horizontal incision line of the molar area was on the mucogingival junction. Thus, the lingual flap had 2 mm of keratinized tissue. Full-thickness buccal and lingual flaps were elevated, and the keratinized tissue band of the molar area was then repositioned to the lingual flap. Nonsubmerged implants (Standard implant, Straumann, Basel, Switzerland; second premolar and first molar: diameter 4.1 mm, length 12 mm; second molar: diameter 4.1 mm, length 10 mm) were placed, and healing caps (diameter 6.5 mm, height 1.5 mm) were connected following a standardized technique.\nThe right palate was chosen as the donor site. The thickness of the palatal tissue, as measured by penetrating to the bone with a periodontal probe, was approximately 3.0 mm. A tinfoil template was used to guide the palatal incision (approximately 7 mm high and 20-mm wide). The graft contouring was performed with a fresh No. 15C scalpel to ensure close adaptation around the implant abutment and a butt-joint marginal adaptation with the lingual tissues. A presuture for the sling suture was made to adapt and fix the graft immediately, and a partial-thickness graft was harvested ().\nThe flap design of the palatal graft followed the technique for the interpositional onlay graft described by Seibert and Louis []. The E-C and CT portions of the graft were determined; the graft was rectangular in shape in the frontal view and wedge shaped in the cross-sectional view ().\nThe graft was positioned over the recipient bed, and the CT portion was inserted under the buccal flap and sutured to the buccal mucosa flap to promptly obtain a blood supply from the buccal flap and the underlying bone tissue. The presutured silk on the E-C portion was tied around the healing caps using sling sutures. The graft was then closely connected to the lingual flap by using an interrupted suture to obtain primary closure in the interproximal area. Consequently, the buccal flap was positioned apically and fixed at the inferior border level of the E-C portion ().\nLight compression was applied to the graft with moistened gauze for about 5 minutes to reduce the thickness of the blood clot and enhance fibrin adhesion. All surgical procedures were performed by one of the authors (K.S.C.).\nPostoperatively, the patient was instructed to rinse her mouth twice a day with 0.1% chlorhexidine solution (Hexamedine, Bukwang Pharmaceuticals, Seoul, Korea) for the first 2 weeks after the surgery. Antibiotic regimens were prescribed for 7 days, and the sutures were removed after 10 days. The patient was rehabilitated with a fixed partial denture after 4 months.\nThe healing was uneventful during the initial healing period, and the graft appeared well integrated with the surrounding tissues. The patient was seen at 2, 4, 6, 8, 16, and 20 weeks postoperatively, and yearly thereafter for 8 years to monitor healing and for plaque control. Clinical and radiographic examinations were carried out once or twice a year ( and ). Plaque control and oral hygiene reinforcement were performed at each visit.\nA clinical examination performed 8 years after surgery found no significant signs or symptoms of inflammation, such as bleeding on probing, gingival redness, or swelling on the keratinized tissue around the implants, and increased keratinized tissue by the creeping attachment was observed. The grafted gingiva had been well maintained throughout the healing period. lists the changes in the width of the keratinized tissue after specific periods of healing. The width of keratinized buccal gingiva had increased to 4 mm, and the buccal vestibule was deeper than in the preoperative condition.