In vitro study on the mechanical strength of abutment screw head under compressive forces

The biomechanical stability of implant-abutment connections is influenced by abutment screw head design. Therefore, it is of interest to compare fracture resistance, deformation and torque loss among hexagonal, star-shaped and conical screw head interfaces. Forty-five titanium assemblies were loaded axially until failure and outcomes were analyzed with ANOVA and Tukey's test. Conical screws showed significantly higher fracture resistance, lower deformation and better preload retention than other designs (p < 0.001). Thus, we show that conical interface screws provide superior mechanical stability under compressive forces.