The authors evaluated, in simulated curved canals, the distortion caused by the use of two rotary systems, the Quantec and the RBS. Twenty epoxy resin simulated root canals were obtained through silver cones #15 with 21 mm and 30 degree curves, checked by a profile projector, according to Schneider "modified" technique, and divided in two groups. They were covered with black adhesive band and instrumented, with the respective rotary systems, according to the manufacturer’s directions, up to size 35 at the apex. After instrumentation, the blocks were uncovered and the angle of each prepared canal was measured again, thus revealing the curvature distortion of the canals through a percental distortion index. The results showed that for the Quantec system the percental average distortion was 8.14%, while that for the RBS was 12.48%, difference statistically significant at the level of 1% (<FONT FACE="Symbol">a </font>= 0.01%).
Endodontics; Dental pulp cavity; Endodontic instrumentation
