Avaliação do preparo de canais mesiais curvos por diferentes sistemas de instrumento único: estudo por microtomografia computadorizada

Abstract

This study, using computerized microtomography, evaluated the effectiveness of three different single-use endodontic instruments, regarding the preparation of curved mesial channels of lower first molars. A total of 27 teeth were distributed in three groups (n = 9), according to the system used in the instrumentation: Reciproc® (G1), Reciproc Blue® (G2) and XP-endo Shaper® (G3). The teeth were scanned by micro-CT, before and after preparation, to analyze the variation in volume and surface area, apical transport and centralization of preparation and the percentage of untouched walls. The percentage of untouched walls along the entire root canal resulted in a similar average between the Reciproc and Reciproc Blue groups (70.75 and 70.24% respectively; p > 0.05) and statistically different when these groups were compared to the XP-endo Shaper group (40.83%), with significance levels of p = 0.0298 and p = 0.0315, respectively. In the apical third (5 mm), fewer walls were touched by the Reciproc (53.07%) and Reciproc Blue (59.79%) groups when compared to the XP-endo Shaper group (21.06%) (p = 0.0282 and p = 0.0096, respectively). The increases in area were 40.92% (Reciproc), 41.65% (Reciproc Blue) with no statistically significant differences between the two groups (p > 0.05); but the XP-endo Shaper group showed an average area increased by 18.74%, showing a statistically significant difference (p < 0.05) in relation to the Reciproc and Reciproc Blue groups. In the apical third, there was an increase in the area of 24.96% in the Reciproc group, 40.27% in Reciproc Blue, and 12.05% in the XP-endo Shaper group; with a statistically significant difference between the XP-endo Shaper and Reciproc Blue groups (p = 0.0089). There was an increase in volume over the entire length of the canal of 35.14% for the Reciproc group, 35.01% for the Reciproc Blue, and 21.10% for the XP-endo Shaper, without statistically significant differences (p > 0, 05). In the apical third, the volume increases were 23.76%, 33.69 and 29.28 for the Reciproc, Reciproc Blue and XP-endo Shaper groups, respectively, without statistical significance (p > 0.05). It was concluded that the three systems produced similar volume increase. However, the XP-endo Shaper® system produced a greater area increase and touched a greater percentage of walls than the Reciproc® and Reciproc Blue® systems.