Evaluation of Crack Propagation after Root Canal Preparation with Continuous and Reciprocating Files and Final Finishing with XP Endo Finisher – An In vitro Study

INTRODUCTION: One of the disadvantages of stainless steel instruments used for root canal preparation is the lack of flexibility and shape memory. The invention of rotary instruments has been successful in overcoming these problems to a greater extent; however, some drawbacks still remain, one of which is vertical root fracture and the cause for it is microcracks formation in dentin, which in turn causes vertical root fracture. There are enough studies for microcracks using different rotary systems and this study compared microcracks with single as well as reciprocating files followed by final finishing with XP endo finisher. Apart from other studies, we used conefocal laser scanning microscope to assess microcrack propagation before and after instrumentation with each rotary system. AIM: To evaluate microcrack propagation in mandibular molars after root canal preparation with continuous and reciprocating file systems followed by final finishing with XP Endo finisher. MATERIALS AND METHODS: Thirty mandibular molars indicated for the extraction due to periodontal causes were selected for this study. They were divided into three groups based on rotary systems used: Group A: ProTaper universal; Group B: ProTaper gold; and Group C: Waveone gold. All specimens were subjected to scanning before instrumentation to assess the presence of any existing cracks. Cone focal laser microscopic scanning is again repeated for each specimen after instrumentation with each rotary system and also after final finishing with XP Endo finisher. STATISTICAL ANALYSIS: One-way ANOVA is used. RESULTS: Crack propagation is the highest with ProTaper universal and least with waveone gold. After final finishing of canals with XP Endo finisher, crack propagation observed was negligible. CONCLUSION: The success of root canal treatment depends on effective disinfection of root canal system. XP Endo finisher can be used as a final finishing file by considering its advantageous properties, moreover crack propagation with XP Endo finisher in an previously instrumented canal is negligible.