A Randomized Controlled Clinical Trial of Two Types of Tapered Implants on Immediate Loading in the Posterior Maxilla and Mandible

Purpose: The aim of this study was to compare clinical outcomes and stability following immediate loading of two types of tapered implants in the partially edentulous posterior maxilla and mandible. Materials and Methods: A randomized controlled trial with 1 year of follow-up was performed on participants missing two consecutive teeth in a posterior quadrant with tapered implants with a hybrid textured surface. Group 1 received Osstem TSIII HA implants, and group 2 received Zimmer TSV implants. Group 1 implants were 4.5 or 5.0 mm in diameter, and group 2 implants were 4.7 mm in diameter; all implants were 10 mm long. Subjects received provisional restorations within 48 hours. Definitive restorations were provided 3 months (mandible) or 6 months (maxilla) later. Outcome measures were survival and success rates, marginal bone level change, implant stability quotient, and peri-implant soft tissue indices. Results: Fifty participants completed the trial (group 1: 52 implants in 26 patients; group 2: 48 implants in 24 patients). The success rates were similar-98.1% in group 1 and 97.9% in group 2-at 12 months after immediate loading, but marginal bone loss was significantly different according to the implant design. Implant stability increased significantly in both arches. There were no significant differences in soft tissue indices between implant systems. Conclusion: If high primary stability is acquired, tapered implants with hybrid textured surfaces are predictable for immediate loading in the posterior maxilla and mandible. In spite of the influence of implant design on marginal bone loss, all tapered implants showed successful clinical outcomes and stability in immediate loading.