Treatment Outcome of Two Adjacent Implant-Supported Restorations with Different Implant Platform Designs in the Esthetic Region: A Five-Year Randomized Clinical Trial

Purpose: The aim of this study was to evaluate the peri-implant soft and hard tissues and satisfaction in patients with two adjacent implant-supported restorations in the esthetic region, treated with two adjacent implants with a scalloped or flat platform. Materials and Methods: The randomized clinical trial consisted of 40 patients allocated to either a scalloped implant group consisting of 20 patients or a flat implant group of 20 patients. Clinical and radiographic examinations were performed during a 5-year followup period, and patient satisfaction during the same period was assessed. Results: The scalloped implant group showed significantly more marginal bone loss (scalloped: 3.2 ± 1.1 mm; flat: 1.5 ± 0.8 mm) and significantly greater bone loss at the interimplant bone crest (scalloped: 2.4 ± 1.0 mm; flat: 1.3 ± 1.0 mm). Furthermore, peri-implant soft tissues showed significantly more bleeding when provided with scalloped implants than with flat implants. Papilla index scores were low in both groups. Patient satisfaction was high in both groups. Conclusion: More bone loss and compromised interimplant papilla regeneration were noted around scalloped implants in the first year, and stable results were observed in the subsequent 4 years with both systems. Scalloped implants seem to offer no benefit when compared to conventional flat implants in the esthetic region.