In Vitro Comparative Assessment of Manual K Files and Rotary File System in Root Canals of Primary Molars

Abstract

Background: Owing to their inherent stiffness, conventionally used stainless steel K-files are inefficient in the ideal cleaning and shaping of the curved and narrow root canals. Hence, NiTi instruments are widely used in pediatric endodontics due to their better cutting efficacy.

Aims: The present study was done to compare and assess the cleaning efficacy of conventional hand K-files to rotary NiTi instruments in root canal preparation in deciduous molars.

Materials and Methods: 60 extracted deciduous molars were extracted and divided into two groups: Group I (n=20): treated with conventional hand K-files and Group II (n=20) treated with 21mm rotary instruments. Teeth sections with Indian Ink removal were visualized under 40X magnification under a stereoscope. Root canal clinical efficacy was then assessed. The collected data were subjected to statistical evaluation.

Results: Highest cleaning efficacy of hand files was seen in the apical third with 83.33% (n=50) complete cleaning. This difference was statistically significant with p=0.003. On assessing the rotary instruments, it was observed that these instruments were better in cleaning middle and coronal thirds with statistically significant (p<0.001). K-files had better efficacy in cleaning the apical third with p=0.273. For the middle third, better cleaning efficacy was seen for rotary files (76.66%, n=46) compared to K-files (p=0.003). For the coronal third, complete cleaning was better with rotary files with 76.6% (n=46) cases compared to hand K-files with 60% (n=36) cases with p=0.002.

Conclusion: The present study concludes that rotary files are better in cleaning efficacy compared to hand K-files in root canal cleaning of deciduous molars. Rotary instruments have advantages of better taper, reduced appointment time, and chairside time with better shaping and success.