RESUMO
Objective: To compare root canal transportation and centering ability of TF Adaptive (TFA), Reciproc (R) and Pro Taper Next (PTN) . Methods: 30 single rooted premolars extracted from orthodontic treatment were randomly divided into 3 groups (n = 10) and prepare by TFA, R and PTN Respectively. The teeth were scanned by Micro-CT before and after instrumentation. The images were reconstructed and exported to Adobe Photo-shop software for analysis. Canal transportation and centering change were determined accordingly. SPSS19. 0 software was used to analyze the data. Results: There was no statistical difference in canal transportation and centering ability for coronal and middle root canal among the 3 groups (P＞ 0. 05) ; for root apical, the canal transportation in group TFA was the smallest, followed by PTN group, that of group R was the largest (between each 2 groups, P ＜ 0. 05), the centering ability of TFA group was the best, followed PTN group, that of group R was the last (between each 2 groups, P ＜ 0. 05) . Conclusion:TFA Ni-Ti instrument is superior to Reciproc and Pro Taper Next for the maintenance of the original orientation of the root canal in root canal preparation.