Áreas de desgaste em pré-molares superiores com três raízes mediante o emprego das técnicas manual, rotatória e reciprocante : avaliação do preparo apical por microtomografia computadorizada

Abstract

Introduction: The aim of the present study was to evaluate the apical enlargement areas of three-rooted human upper premolars by means of micro-computed tomography-(μCT). Métodos: After the cavity access, canal exploration and odontometry, eighteen samples were divided into three groups according to the preparation technique: manual group (Hand) (n=6) teeth were instrumented by crown-down technique and stainless steel files; ProTaper group (GPt) (n=6) teeth were instrumented by using the Rotary movement and ProTaper system; and WaveOne group (GWO) (n=6) teeth were instrumented by WaveOne instrument operated in reciprocating movement. The final canal enlargement at mesiobuccal (MB), distobucal (DB) and palatal (P) roots match 0,25 mm, 0,25 mm and 0,40 mm, respectively. Micro-computed tomography-(μCT) was performed before and after preparation. The pre and post images corresponding to 0, 2, 4 and 6 mm from the apical stop were overlaid and the difference between the areas of surgical and anatomical canals were measured with the aid of PhotoShop program. The groups were statistically compared using two-way Analysis of Variance (ANOVA) and Tukey post-hoc test at 5% significance level. Results: There was no difference between the preparation techniques. Regardless of the technique, we found further enlargement toward the cervical portion of the canal. Some canals had excessive enlargement, but no perforation. Moreover, untouched areas were observed in some roots. Conclusion: There were no differences in all roots when comparing hand, rotary and reciprocating techniques. All of them are safe for the instrumentation of the apical third of three-rooted premolars.