Shaping ability of a new heat-treated NiTi system in continuous rotation or reciprocation in artificial curved canals.

The purpose is to evaluate canal transportation of a new heat-treated NiTi system, the Endostar E3 Azure operated in continuous rotation or reciprocation. 40 resin blocks were divided into two groups. The first was shaped in continuous rotation while the second in reciprocation. A preoperative and two postoperative images were taken, one after the use of the 20/06 and one after the 25/06. The images were superimposed to determine canal transportation. Time required for canal shaping was recorded. One-sample and student t tests, repeated-measure analyses of variance, univariate analyses and Bonferroni multiple comparisons tests were used for statistical analysis. The significance level was set at p < 0.05. There was no significant difference between continuous and reciprocating motion with the 20/06 and 25/06, respectively, at 1 mm (p = 0.761, p = 0.559), 2 mm (p = 0.584, p = 0.810) and 3 mm (p = 0.651, p = 0.070). The reciprocating motion showed significantly less canal transportation at 5 mm (p = 0.049, p < 0.001) and 7 mm (p < 0.001, p < 0.001) for the 20/06 and 25/0.6. Continuous rotation was more time-consuming than reciprocation (p < 0.001). The Endostar E3 Azure in reciprocation respected the original canal curvature better than in continuous rotation at all levels, and required less time to prepare artificial curved canals. Endodontists should know the shaping abilities of novel heat-treated NiTi files, regarding canal transportation and its relation with the instruments' motion and apical diameter enlargement.