The Long-Term Retention Force and Fatigue Performance of CAM PEEK Clasps: An In-Vitro Study

The investigation into the capacity of PEEK material clasps to deliver sufficient retention force, maintain morphological stability, and exhibit fatigue resistance over prolonged periods is of significant importance.

This study employed a fatigue testing machine to simulate clinical scenarios with varying concave depths (0.25mm, 0.50mm, 0.75mm) and conducted 7200 cycles of fatigue tests on clasps made of different materials. The initial retention force, dynamic changes in retention force, and deformation values of the clasps were measured and analyzed, and their surface morphology was observed using Scanning Electron Microscopy (SEM).

The initial retention force of A-type PEEK clasps exhibited an increase with the concave depth, whereas no significant difference was observed in the initial retention force of B-type PEEK clasps at different concave depths. Following fatigue cycling, the retention force of PEEK clasps decreased more gradually compared to metal clasps, with PEEK-A clasps demonstrating more stable retention force in deeper concave conditions. Furthermore, after prolonged fatigue cycles, PEEK clasps exhibited smaller permanent deformation than metal clasps, and their surface remained smoother without evident wear or cracks.

In comparison to metal clasps, PEEK clasps offer more stable retention force and reduced permanent deformation in long-term clinical applications, making them more suitable for periodontal disease abutments with deeper concavity.