Fatigue resistance and structural integrity of fiber posts: Three-point bending test and SEM evaluation

Abstract

The Aim of this study was to assess the fatigue resistance of different types of fiber posts, and to observe their ultrastructure through a scanning electron microscopy (SEM) before and after undergoing the fatigue test. Six types of fiber posts were selected in this study. Experimental GC fiber post, Para Post Fiber White, FibreKor, DT Light-Post radiopaque, FRC Postec, and Luscent Anchors. A three-point bending machine, loading at an angle of 90° and a frequency of 3 Hz was employed for fatigue testing until 2 million cycles. SEM evaluation was performed using a 3-stepscale method to assess the fiber/resin ratio and fibers dimension. The fatigue test showed statistically significant differences among the different posts. GC fiber post and FRC Postec performed better than all the other groups, withstanding the entire load cycles. All the other posts fractured before the end of the test. SEM observations of the surface integrity of the fiber posts showed that GC fiber post, DT Light-Post radiopaque and FRC Postec obtained better scores for both longitudinal sections and the cross sections. There is a large variation of different kinds of fiber posts in response to a fatigue resistance test.