Abstract : This study aims to evaluate the canal-centering ability of three single-file reciprocating systems: Reciproc Blue, R Motion, and WaveOne Gold systems. Forty-five S-shaped endodontic resin blocks size #15 were divided into three groups. Each of the groups (n = 15) were prepared, imaged, and analyzed: Group (A) RB system; instrument RB 25/08; Group (B) RM system; instrument RM 25/06; Group (C) WOG system; instrument WOG 25/07. Resin blocks were photographed before and after the preparation in the same position and superimposition of both images was performed. 12 measuring points were identified for each wall of the canal (from point A at the end of apical foramen to point L at the beginning of coronal third), with 1 mm distance between each point except for the point B, which is 0,5 mm away from both point (A) and point (C). The amount of resin removed from the inner and outer walls of the canal was measured, and the transportation of the centering ability of the canal was calculated. LSD test was performed to determine the exact location of the differences between groups (p < 0.05). Results: Statistically significant differences were found in the middle third where the RB system achieved the greatest shifting from the canal-centering, while in the apical and coronal thirds all three analyzed systems tended to prepare similarly without statistically significant differences. In Conclusion RM system showed the lowest value of shifting from the canal-centering, therefore, it is the most conservative system with the most centered preparation.