FRACTURE RESISTANCE OF LOWER MOLARS AFTER MESIAL CANALS PREPARATION WITH THREE DIFFERENT ROTARY FILES (A COMPARATIVE IN VITRO STUDY)

Abstract

Introduction: Rotary canal preparation might lead to tooth micro-cracking due to stresses on root canal walls. It is not known if modifications in rotary file manufacturing and the way they work inside the canals have an impact on the resistance of teeth to fracture under loading or not.Aim of the Study: To compare the fracture resistance of lower molar teeth after the preparation of mesial canals using three different rotary files: Protaper Ultimate (PTU), Protaper Gold (PTG), and Wave One Gold (WOG).Materials and Methods: Forty-four permanent lower molar teeth were selected in this study and were randomly allocated into four groups (n=11 each). Access cavity was done for all teeth. Group I: Protaper Ultimate (PTU) files were used in both mesial canals up to size F2 (25/08). Group II: Protaper Gold (PTG) files were used in both mesial canals up to size F2 (25/08). Group III: Wave One Gold (WOG) reciprocating files were used in both mesial canals up to the primary file (25/07). Group IV: Control Group; teeth where access cavities were done with no further preparation to the root canal. Results: The control group significantly demonstrated the highest values of fracture resistance in comparison to all the experimental groups. While no significant difference was found between the fracture resistance values of the three experimental groups. Conclusion: Both rotary file systems (PTU, PTG) showed higher fracture resistance values, when compared to the reciprocating file system (WOG), although the difference was statistically non-significant.