Stiffness, elastic limit, and strength of newer types of endodontic posts

Objectives: To determine the stiffness, elastic limit, and strength of a selection of endodontic posts recently introduced onto the market. Methods: Endodontic posts of zirconia (Biopost, Cerapost), titanium (PCR), and carbon fiber (Composipost) were cemented in a brass block and loaded at an angle of 45° in an Instron Testing Machine. From the recorded relationships between force and deflection the three mechanical properties were determined (n = 10 in each group). Results: The ceramic posts were very stiff and strong, with no plastic behavior. The PCR post was as strong as, but less stiff than, the ceramic posts. Composipost had the lowest values for stiffness, elastic limit, and strength of the posts investigated. Conclusion: The posts under investigation differed significantly with respect to mechanical properties.