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

## TL;DR

This study compares the mechanical strength of different abutment screw head designs under compressive forces.

## Contribution

The study introduces a comparison of fracture resistance and mechanical stability among three screw head designs.

## Key findings

- Conical screws showed significantly higher fracture resistance compared to other designs.
- Conical screws exhibited lower deformation and better preload retention.
- Hexagonal and star-shaped designs had inferior mechanical performance.

## Abstract

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.