Reproducibility of accelerated fatigue test of dentin-composite discs under cyclic diametral compression

Objectives: This study considers the reproducibility of a newly proposed Medical Device Development Tool (MDDT) for testing the durability of the tooth-restoration interface in dental resin-composite restorations. Methods: The tool is in the form of an accelerated fatigue test using dentin-composite discs subjected to cyclic diametral compression with a linearly increasing load amplitude. Three operators performed the test separately, with each using 30 specimens. Results: The 3 runs produced very similar mean numbers of cycles to failure as well as survival probability plots, demonstrating the test's reproducibility. Geometric analyses did not show any strong association between dimensional variations and the number of cycles to failure. Fatigue parameters derived from the test results also agreed with some of those reported in the literature based on beams in 4-point bending. Significance: The proposed MDDT is a reproducible and reliable durability test for resin-composite systems.