Periimplant tissue response following immediate provisional restoration of scalloped implants in the esthetic zone: A one-year pilot prospective multicenter study

Statement of problem: Flat platform implants may present a limitation when irregular or scalloped bone topography is encountered, resulting in compromised periimplant bone and soft tissue contours. Purpose: This 1-year pilot prospective multicenter study assessed the success rates and periimplant tissue response of scalloped implants undergoing immediate provisional restoration in the maxillary esthetic zone. Material and methods: Twenty-nine patients, 15 men and 14 women, mean age of 45.1 (range: 18-70) years, were included in this study. Thirty-eight scalloped implants with a 1.5-mm machined surface collar and a titanium oxide surface (TiUnite) were placed both in healed sites (15) and extracted sites (23), and provisional restorations were placed immediately. The definitive restorations were placed an average of 12.6 months later. The patients were evaluated clinically with respect to gingival papilla appearance, presence or absence of plaque and gingivitis, and radiographically for bone level measurements at 0, 3, 6, and 12 months after implant placement. Descriptive statistics were used to analyze the data. Results: At 12 months, all implants remained in function. The mean (SD) marginal bone change from the time of implant placement to 12 months was 0.1 (3.3) mm. For implants placed in extracted sites the mean (SD) marginal bone change was 1.0 (3.6) mm, compared to those in healed sites, which was -1.6 (1.9) mm. The marginal bone level in 9 of the initial 22 sites (41%) was retained in the scalloped area of the implants at 12 months. In the follow-up, after 3 months of function, no significant changes with respect to mean papilla index score were observed. The patients maintained acceptable hygiene throughout the follow-up period. Conclusions: Although favorable implant success rates and periimplant tissue response can be achieved with immediate provisional restoration of scalloped implants in the esthetic zone, bone was not regularly maintained at the original levels around the scalloped area of the implants.