RESUMO
Endodontically treated teeth are weakened structurally for vast decayed areas, access cavity preparation and filling. RCT is a common routine dental service in daily practice and the use of composite post are proposed for the increase of weak teeth, this study designed to evaluate the effect of composite posts on RCT teeth. The study was experimental. A total of 20 maxillary central teeth - extracted for periodontal reasons - were divided in control and experimental groups. The teeth were endodontically treated. In ontrol teeth, access cavities were restored with Tetric composite and Bonding agent [3M Scotchbond Multi-purpose Plus]. In experimental group, Tetric composite posts were prepared after canal preparation and canals were cemented with Variolink Dual Cure and the same bonding agent. Finally, access cavities were restored with Tetric composite. The teeth were mounted in acrylic blocks and the force caused to break them was determined by Instron Universal Machine. The force to break the teeth with composite posts was greater [760 +/- 141.4 N]. This force was 590 +/- 191.5 N in teeth without post and the difference between two groups was statistically significant [P<0.04]. The use of composite post in invitro situation can increase the strength of RCT treated teeth against the exposed forces