An Ex vivo Analysis of Apical Transportation in Root Canals Prepared with BT Race Rotary and Hand K-Flexofile by Cone Beam Computed Tomography

Background and purpose: The purpose of mechanical cleaning of the root canal is to clean the canal walls, create a conical shape to facilitate access, effective washing, and filling all areas of the root canal. Errors such as root canal transportation are cuased by excessive dentin removal from the canal. The objective of this study was to investigate root canal transportation by a BT Race rotary and manual file with Cone Beam Computed Tomography (CBCT). Materials and methods: An Ex-vivo study was conducted in 54 extracted first molars. Root curvature was measured by Schneider's method. Preparation was performed in two groups (n= 27 per group) with manual and rotary files. CBCT images were prepared pre and post instrumentation of the canals. SPSS 18 Software was used to measure the amount of canal transportation. Results: The mean differences of canal transportation between the two groups were 0.24 ± 0.16, 0.19 ± 0.13mm, and 0.17± 0.12mm at T1 (1 mm from apical foramen), T2 (2 mm from apical foramen), and T3 (3 mm from the apical foramen), respectively. The total deviation was 0.022mm in this study. The rotary and manual files at T1 (P=0.51) and T3 (P=0.57) were not significantly different in causing transportation but T2 was found to cause significant canal transportation (P=0.027). Conclusion: The average canal transportation in 2mm canal from the apical foramen by manual files was lesser than the rotary files. BT race and K-flexo file instruments can preserve the curvature of the root canals. Therefore, both systems can be used in clinical settings with minimal apical transportation.