Prospective randomized controlled clinical study comparing two types of two‐piece dental implants supporting fixed reconstructions – results at 1 year of loading

Objectives To analyze clinical, esthetic, radiographic, and prosthetic outcomes of implants and implant‐supported reconstructions using two types of dental implants with non‐matching implant abutment junctions. Materials and methods A total of 64 patients in need of dental implant therapy with fixed reconstructions were consecutively enrolled. They were randomly assigned to either one of two implant systems (S1: Astra Tech Osseospeed and S2: Straumann Bone Level). Baseline (day of loading) and 1‐year measurements included demographics, radiographic, clinical, biologic, prosthetic, and esthetic outcomes. All data were analyzed at the patient level and at the implant level. The nonparametric Mann–Whitney U‐ test was used to detect differences in continuous variables between two independent groups. Results Ninety‐seven implants (S1 = 54, S2 = 43) were placed and loaded with fixed reconstructions in 64 patients. No implant was lost during the 1‐year observation period resulting in a 100% survival rate for both implant systems. At the patient level, the mean marginal bone level at implant insertion was −1.30 mm ( SD  ± 1.00 mm) for S1 and −1.26 mm (±1.22 mm) for S2 (negative values indicating bone levels coronal to the implant shoulder). At the time of loading, these distances measured 0.29 mm (±0.44 mm) for S1 and 0.22 mm (±0.43 mm) for S2. At the 1‐year follow‐up, these distances were 0.37 mm (±0.39 mm) for S1 and 0.39 mm (±1.02 mm) for S2. Technical complications of the reconstructions only occurred in Group S1, with a rate of 12% (patient level) ( P  > 0.05). Biologic complications were observed at a rate of 6% (S1) and 3.2% (S2) at the patient level ( P  > 0.05). Conclusions Both implant systems revealed 100% survival rates and minimal changes of the marginal bone levels during 1 year of loading. Few technical and biologic complications occurred. Therefore, both implant systems can be recommended for fixed reconstructions.