Influence of Timing on the Horizontal Stability of Connective Tissue Grafts for Buccal Soft Tissue Augmentation at Single Implants: A Prospective Controlled Pilot Study.

PURPOSE: The timing for soft tissue augmentation during implant therapy is still debated. Therefore, the present study clinically evaluated whether immediate versus delayed soft tissue augmentation procedures had an impact on the stability of peri-implant mucosal thickness (PMT). MATERIALS AND METHODS: Patients requiring a single implant posterior to the canines in association with soft tissue augmentation procedures at the buccal aspect of single implants using a connective tissue graft (CTG) were enrolled. Patients were randomly allocated to 2 different timing protocols: simultaneous implant and CTG placement (test group) or implant placement and then CTG placement after 3 months (control group). PMT was measured clinically at the mid-buccal aspect of the implant site by bone sounding with an endodontic K-file using customized acrylic stents. PMT measurements were recorded before and after implant placement and at 1, 2, 3, 4, 6, 9, and 12 months after implant insertion. Parametric statistical tests were used to compare PMT between the test and control groups at each study period and to evaluate changes in PMT over time. The level of significance was set at a P value less than .05. RESULTS: Fourteen implants placed in 14 patients were available for statistical comparison. At 12 months, the difference in PMT between the test and control groups was 0.12 ± 0.51 mm. This difference was not statistically significant (P = .54). A significant increase in PMT was observed from baseline to 12 months after implantation in the test (P = .004) and control (P < .001) groups. CONCLUSIONS: The present study indicated that changes in PMT after CTG placement were not influenced by the timing of soft tissue augmentation and remained stable up to 1 year after implant insertion.

Histologic and Radiographic Comparison of Bone Scraper and Trephine Bur for Autologous Bone Harvesting in Maxillary Sinus Augmentation.

PURPOSE: The aims of this study were to investigate the best two of five common methods of collecting autologous bone (preliminary study [PS]) and to test clinically the effects of autografts harvested using a trephine bur or bone scraper for sinus augmentation surgery (main study [MS]). MATERIALS AND METHODS: In the PS, five autograft samples from five patients (n = 25) were harvested with a bone scraper, round bur, piezoelectric device, implant bur, and trephine bur and were processed for histomorphometric analysis. In the MS, sinus augmentation was performed on 20 patients using bovine-derived bone substitute and autograft collected with a trephine bur (group A, n = 10) or collected with a bone scraper (group B, n = 10). Narrow implants were also placed. At 6 months, changes in graft volume were evaluated with cone beam computed tomography. The amounts of regenerated bone, residual graft, and osseointegration of the implants were assessed histologically. RESULTS: In the PS, the trephine bur and bone scraper harvested bone chips that were medium to large and more vital than those obtained with the other tools. In the MS, no significant differences were seen between groups in terms of the amount of residual biomaterial, regenerated bone, change in graft volume, and osseointegration. CONCLUSION: Biologic differences between these two bone particulates may not influence regeneration and implant osseointegration in sinus augmentation when mixed with xenograft bone.

Alveolar antral artery isolation during sinus lift procedure with the double window technique.

The sinus lift technique, introduced in 1976 by Tatum and subsequently described by Boyne in 1980, is nowadays considered a safe and reliable procedure for the rehabilitation of the atrophic upper posterior maxilla. The alveolar antral artery (AAA) is anastomoses between the posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA) and may be present in the sinusal antrostomy. The haemorrhage of this vascular bundle represents the second intra-operatory complication in term of frequency during sinus lift procedure. Purpose of this study was to illustrate and describe a new technique allowing the AAA isolation during sinus lift procedure in cases in which the artery is clearly present inside the surgical area, detectable through CT scan exam. Presence, course and possible identification of the alveolar antral artery are also discussed, according to the studies present in the literature.

Clinical investigation of mucosal thickness stability after soft tissue grafting around implants: a 3-year retrospective study.

PURPOSE: To assess the long-term stability of gingival grafts placed around dental implants at the time of second surgery uncovering and to further investigate the association between mucosal thickness (MTh) by demographic variables and clinical investigation. MATERIALS AND METHODS: Fourteen patients with submerged dental implants covered by inadequate keratinized mucosa were studied. The subjects underwent a periimplant plastic surgery (PPS) at the second-stage dental implant surgery and free gingival autograft orsubepithelial connective tissue graft were used according to the patients' clinical situation. Clinical measurement of MTh was assessed by bone sounding with a periodontal probe using customized acrylic stents andthe values were recorded at baseline (day of graft) and at 0.5, 1.5, 4, 12, 24 and 36 months after grafting. RESULTS: At 12 months postoperatively, the mean MTh was 2.89 mm, with a mean additional increase of 1.75 mm when compared with baseline (P=0.0001). No statistically significant differences in MTh were found between the 12- and the 36-month observations (P=0.09). In addition, at 36 months, a thin mucosa was associated with a greater increase in the MTh compared with a thick mucosa (2.14 and 0.64 mm, respectively, P=0.006). Similarly, the mandibular sites were associated with a greater increase in the MTh in comparison with the maxillary sites (2.17 and 0.81 mm, respectively; P=0.02). CONCLUSIONS: Within the limitations of this investigation, the data suggest that PPS at the second-stage dental implant surgery could results in additional increases in MTh, especially when it is performed in areas where the mucosa is of a thin biotype.