[ cleaning efficacy of manual files compared with two rotary instruments in the root canal of permanent molars: an in vitro study]

ABSTRACT

Rotary files may be cause anatomical changes in apical area. The aim of this study was evaluation of maintenance of the canal's curve using Flex Master and Protaper rotary instruments. In this in vitro study, we used 30 mesiobuccal roots of first permanent maxillary molars with a mean length of 18-23 milimeters and a mean curve of 15-40 degrees. Sampling was simple and the specimens were divided into two groups of fifteen. In each group, the canals were prepared by crown down method after the access step. Then they were prepared using Flex master and Protaper according to their company's instruction. After finishing the preparation steps, hand instrument number 30 was placed in the canals and under the same primary condition we evaluated the final angle by digital radiographic system. For evaluation of the results, we used variance analysis, t test and covariance analysis. The mean angle of apical transportation after using two Flexmaster and Protaper rotary systems was 6/19 +/- 3/07 and 5/52 +/- 2/87 degree, respectively. The mean apical transporation using the Flexmaster system was more than Protaper system but the difference between them was insignificant [P>0/ 05]. Because of using these two rotary systems, we had apical canal transportation. This transportation by using Flexmaster system was more than the Protaper system, but it was not significant