Influence of Implant Macrodesign on Primary Stability Across Different Bone Density Models: A Comparative In Vitro Study

Background: Implant macrogeometry and bone density are major determinants of primary stability. This study aimed to evaluate primary stability across different implant macrodesigns and block models. Materials and Methods: A total of 153 implants were divided into Group 1 (AnyRidge), Group 2 (BlueDiamond RC), and Group 3 (BlueDiamond NC) (n = 51 each). Each implant was sequentially tested in synthetic D1–D4 bone models. Insertion torque values (ITV) and implant stability quotient (ISQ) were recorded. Results: In D1, ITV was highest in Group 1 (69.51 ± 1.50 Ncm), followed by Group 2 (53.82 ± 6.75 Ncm) and Group 3 (49.31 ± 7.00 Ncm) (p < 0.01, p < 0.001). In D4, ITV decreased to 34.71 ± 3.23, 19.90 ± 3.08, and 11.18 ± 2.14 Ncm, respectively (p < 0.001). D1 ISQ values were 84.53 ± 2.51, 72.08 ± 3.69, and 66.33 ± 2.63, respectively (p < 0.001). In D4, ISQ values were 60.29 ± 3.84, 52.86 ± 3.73, and 52.18 ± 2.48, respectively (p < 0.001); Groups 2 and 3 did not differ significantly. Conclusions: Implant macrodesign influences primary stability, with AnyRidge demonstrating the highest ITV and ISQ values in D1 as well as D4. Further clinical studies would be beneficial to support these findings.