关键词: 往复运动, 单支锉, 根管预备, 成形能力

Abstract:

Objective This study aims to evaluate the shaping capability of Reciproc, WaveOne, Mtwo, and ProTaper instruments in simulated root canals. Methods A total of 40 simulated resin blocks were divided randomly into four groups. Each group was prepared with Reciproc (Group 1), WaveOne (Group 2), Mtwo (Group 3), and ProTaper (Group 4). The preparation time and reduction in working length after preparation were measured. Pre-and post-operative images were obtained with a scanner and superimposed through Photoshop. The changes in canal curvature and material removal from the inner and outer canal walls at 10 points beginning at 1 mm from the end point of the canal were measured with Image J. Centering capability was determined accordingly. Data were analyzed through one-way ANOVA, SNK, and Kruskal–Wallis at a significance level of P<0.05. Results The preparation time of Group 2 was (53.7±6.7) s, whereas those of Groups 1, 3, and 4 were (86.9±8.1) s, (112.2±8.2) s, and (177.9±11.2) s, respectively; the difference was found to be significant (P<0.05). The reductions in working length among the four groups after preparation were not significantly different (P>0.05). The canal curvature for Groups 1 to 4 were 2.671°±0.637°, 2.667°±0.450°, 3.664°±0.870°, and 3.797°±0.601°, respectively. The changes for Groups 1 and 2 were significantly smaller than those for Groups 3 and 4. At the 3 mm point, the transportation of Group 1 was (-0.016±0.094) mm, which was significantly less than that of the other instruments (P<0.05). At the 4 mm and 5 mm points, the transportation values of Group 2 were (-0.080±0.104) mm and (-0.312±0.088) mm, which were significantly less than that of Group 1 [(-0.243±0.099) mm, (-0.404±0.064) mm, P<0.05]. Conclusion Reciproc and WaveOne can complete preparation faster and can maintain the original canal curvature better than Mtwo and ProTaper. Reciproc exhibits superior centering capability in the apical part of the canal, whereas WaveOne exhibits superior centering capability in the middle part of the canal.

Key words: reciprocating movement, single files, root canal preparation, shaping capability