Influence of Implant-Specific Characteristics on Insertion Torque and Primary Stability: An Ex Vivo Comparison of Two Implant Systems with a Shared Macrodesign

Objectives: The aim of this study was to compare insertion torque (IT) and primary stability, assessed by resonance frequency analysis (RFA), between two implant systems with a shared macrodesign but different surface morphology and titanium grade in a standardized ex vivo porcine bone model. Methods: Sixty implants (OmniTaper EV and Xive; n = 30 per group) were inserted into standardized porcine rib bone blocks using identical osteotomy protocols. Peak insertion torque and primary stability, assessed by resonance frequency analysis (RFA), were recorded immediately after placement. Between-group differences were evaluated using appropriate statistical methods. Results: Bone density did not differ significantly between groups. OmniTaper EV implants demonstrated significantly higher insertion torque (28.2 ± 6.5 Ncm vs. 24.2 ± 6.2 Ncm; p = 0.020) and higher ISQ values (74.1 ± 6.0 vs. 69.8 ± 6.9; p = 0.013) than Xive implants. Mixed-effects analyses confirmed both findings after adjustment for clustering. No significant correlation was found between insertion torque and ISQ. Conclusions: Despite sharing a common implant design concept and standardized osteotomy preparation, the investigated implant systems demonstrated significant differences in insertion torque and primary stability. The findings indicate that implant-specific characteristics, including surface morphology and titanium grade, may influence implant–bone interface mechanics during insertion. However, their individual contributions cannot be distinguished within the present study design and should therefore be interpreted as the combined influence of implant-specific characteristics.