Estudo sobre o transporte apical e capacidade de limpeza de sistema de instrumento único associado a diferentes técnicas de cateterismo

Abstract

The purpose of this study was to evaluate apical transportation using CT Scans, and, using histological analysis, to evaluate the cleaning effectiveness of different glide path techniques associated with the use of Reciproc system`s R25 instrument. To perform the experiment, 52 mandibular molars were selected, with mesial root canal curvature between 20° and 40° and canal curvature radius less than or equal to 10 mm. Size 10 K-type instruments were used to determine the presence of independent foramen. In order to standardize tooth size, the crowns were partially sectioned at 16 mm and then measured 3 mm in the mesial root, which were transferred to the distal root, to be sectioned at that point. The selected teeth were divided into four groups of 13: Group 1: glide path with manual file, sizes 10 and 15 and instrumentation with the R25; Group 2: Reciproc R25 without a glide path; Group 3: the glide path performed with PathFile and instrumentation with the Reciproc R25 and Group 4: control group, no instrumentation. The distal root was then embedded in resin blocks for the scans to be standardized in the same position, before and after instrumentation, and to be fixed in a vise, in order to standardize instrumentation position. The working length of the mesial canals was set at 0.5 mm from the apex. After performing the glide path, the root canals were prepared following manufacturer recommendations. Sodium hypochlorite 2.5% was the irrigating solution used. After instrumentation, teeth again underwent CT scanning, after which the apical third of each specimen was subjected to routine histotechnical processing in order to obtain 12 sections 5 μm thick. Apical deviation was assessed by applying formulas to values obtained before and after instrumentation and histological analysis was performed by evaluating the histological sections with a 230x magnification and the quantification of debris through the superposition of a grid. Data were subjected to the Kruskal-Wallis Test and the Dunn Multiple Comparisons Test. The results of the apical deviation presented no significant difference between the experimental groups (p > 0,05). As for cleaning ability, the difference between groups 1 and 2 was found to be statistically significant (p ˂ 0,01). The methodology and the results lead to the conclusion that the glide path technique used did not produce a statistically significant difference in apical deviation. However, the Reciproc system instrumentation technique, without a glide path, showed greater capacity for cleaning the root canal system.