A Comparative Study Of The Cleaning Ability For Ni-Ti ProTaper Instruments And Stainless Steel Hand File During Root Canal Preparation

Objective:The purpose of this study was to compare the cleaning effect of rotary ProTaper, conventional stainless steel K-file and ProTaper NiTi hand instruments during canal preparation in extracted human teeth. Methods:40 root canals with curvature ranging between 11° and 25° were selected. According to the degree and radium of canal curvature, 40 premolars were randomly divided into 4 groups of 10 teeth each. (1) The control group; (2) The stainless steel K-file group, which were prepared with stainless steel K-file by means of step-back technique. (3) The NiTi rotary ProTaper group, which were prepared with NiTi rotary ProTaper instrument by means of crown-down technique. (4) The ProTaper NiTi hand instruments group, which were prepared with ProTaper NiTi hand instruments by means of step-back technique. After each instrumentation, the canal was irrigated with 2ml of 2.5% NaOCL and at the final of canal instrumentation, the canals were flushed with 10ml of 2.5% NaOCL and 5ml of distilled water. After the canal preparation, the canals were splitted longitudinally, the amount of debris and thickness of smear layer on the canal walls were evaluated by scanning electron microscopic photomicrographs (SEM) , the debris and smear layer on the canal walls were separately recorded and analysed to evaluate the cleaning ability of instrumentation. The data were analysed separately by Wilcoxon's test and statistical analysis software SPSS 10.0 . Results:In the NiTi rotary ProTaper group, the debris and smear layer on the canal walls were less than those of group stainless steel K-file and group ProTaper NiTi hand...