Influência de instrumentos endodônticos com diferentes conicidades na qualidade da instrumentação e na remoção de dentina radicular em incisivos inferiores

Abstract

The use of instruments with reduced tapers has been suggested for endodontic treatment to reduce root dentin removal. Thus, the study aims to evaluate the influence of endodontic instruments with different conicities (.04 and .06) on the quality of the instrumentation and the volume of dentin removed after the preparation of lower incisors with circular and oval canals, using microcomputed tomography ( micro-CT). Forty lower incisors with single canals were subjected to micro-CT and divided into two groups (n=20): oval canals and circular canals. The teeth were accessed and prepared with the VDW ROTATE instruments in the sequence: 15/.04, 25/.06 and 35/.04. After preparation with the 35/.04 instrument, the teeth were re-scanned by micro-CT and prepared with the 35/.06 instrument and the teeth were scanned again. After the scans, the percentage of unprepared area and volume of dentin removed were calculated in the CTAn program. The data were subjected to statistical analysis using the Mann Whitney, Wilcoxon or Student's T tests according to the normality of the samples (P<0.05). It was observed that in both groups, the percentage of unprepared area was higher after preparation with conicity .04 when compared to .06 (P<0.05). On the other hand, the percentage of dentin removed was lower after preparation with the .04 conicity when compared to .06 (P<0.05). When comparing the type of anatomy (oval and circular canals) no statistical difference was observed between the percentage of unprepared area and dentin removed (P>0.05), however, it was found that the surface area and volume of the canals oval canals was significantly larger than circular canals, which is justified by the anatomical difference itself (P<0.05). Therefore, it was concluded that the use of instruments with reduced conicity (.04), despite removing a smaller amount of root dentin, promotes a greater percentage of unprepared area of the canal, which can influence the cleaning of the canals.