Study on flexural strength and microstructure of four different fiber-reinforced composite posts

Objective To test flexural strength of fiber-reinforced composite posts(FRC-posts) and to investigate the relationship between microstructure and flexural strength. Methods Four types of fiber-reinforced composite posts were tested for this study.They were D.T.Light-Post (BISCO),ParePost Taper Lux (Coltene/Whaledent),LuxaPost (DMG),and domestic fiber post (Shi De-long). Five specimens of each experimental group were selected for a three-point bending test and one was processed for SEM evaluation. After three-point bending test,the posts with the highest and the lowest values of flexural strength of each group were additionally processed for SEM analysis. Results The fracture load of the tested posts ranged from 157.40 N to 127.80 N,and the flexural strength from 820.03 MPa to 937.95 MPa.The differences in fiber/matrix ratio ranged from 54.56% to 78.68%. Of the various structural characteristics investigated,only the fiber/matrix ratio showed a significant linear correlation to the flexural strength. Conclusions It can be proved that flexural strength of fiber-reinforced composite post is related to its microstructure and the flexural strength increases with the increase of fiber/matrix ratio.