A Comparison of Three Nickel Titanium Rotary Systems, Reciproc, Protaper and Protaper Next, For Working Time and Change of Root Canal Curvature

The errors in the preparation such as change in canal curvature especially in curved canals almost always happen in the preparation step. Nickel- titanium rotary files that have been designed for canal preparation can reduce these problems. Preparation time is also important in root canal therapy and a rotary system which can prepare the canal in a lesser time, is more appropriate. The purpose of this study was to compare the curvature change of canal after preparation and instrumentation time in three rotary system; Reciproc, ProTaper and ProTaper Next. Forty-five resin blocks were used in this study. Each canal had a curvature of 25o to 35o and 15 mm length. Pre-instrumentation images of all blocks were taken with stereomicroscope and blocks were divided into three groups and each group was prepared with one of these systems: Reciproc, ProTaper and ProTaper Next. Post-insrtumentation images of all blocks were as well taken and the canal images were overlapped, and the curvature change of canal after preparation was measured. Active instrumentation time was also calculated during the preparation. Statistical analysis was performed using SPSS, version 16. Data were analyzed by ANOVA and Tukey tests (α=0.05). The results showed that the active instrumentation time was significantly less in the Reciproc group (P=0.034, P<0.001). Curvature change of canal after preparation was not significantly significant. According to the results, the three files in this study prepare the canal properly and change canal curvature negligibly and are safe instruments for preparation of curved canals. Reciproc files need lesser time for preparation and can prepare the canal faster.