Comparative evaluation of incidence of dentinal defects after root canal preparation using hand, rotary, and reciprocating files: An ex vivo study

Aim: To compare dentinal cracks incidences after root canal preparation using Hand K-files; Rotary files: Protaper NEXT (PTN), Hyflex Controlled Memory (CM); and Reciprocating files: Wave One and Wave One Gold files. Materials and Methods: Hundred extracted human mandibular first premolars with straight root canals were taken postextraction and were allocated randomly into five groups (n = 20 teeth per group). The canals were instrumented using Hand K-files, Protaper Next (PTN), Hyflex CM, Wave One, and Wave One Gold systems. Group 1-Control group comprised of canals prepared by Hand files. Further, the roots were sectioned at three levels: 3, 6, and 9 mm horizontally from the apex using a saw at a low-speed saw and under water cooling. These slices were examined under a stereomicroscope at 25× magnification and the presence of any dentinal cracks was noted. The frequency of cracks was presented in number and percentage. Intergroup comparison of crack frequency was performed using analysis of variance. Results: No cracks were observed in the control group. In all the other groups, dentinal cracks were observed. The rotary files PTN and Hyflex CM files produced significantly fewer dentinal cracks than the reciprocating Wave One and Wave One Gold files (P < 0.05). The reciprocating files significantly produced more cracks apically than the rotary files (P < 0.05). Analyses were performed on SPSS software (windows version 22.0). Conclusion: Instrumentation with file systems can cause crack formation in the dentinal wall of the root canal. Determination of which files to choose for root canal preparation is technique sensitive and each instrument type has own benefits. However, care should be taken while biomechanical preparation to avoid dentinal cracks formation.