[Comparison of root canal transportation during canal preparation with hand instrumentation and reciprocal automatic device]

Cleaning and shaping of the root canal system is an important objective of root canal therapy. Many automatic devices have been produced to simplify the preparation and to decrease instrumentation time. One of these automatic devices is the new reciprocal handpiece [TEP-E10R] known as general name "Endogripper". The purpose of this study was to compare canal transportation with hand instrumentation technique and reciprocal instrumentation technique with TEP-E10R handpiece. In this invitro study 60 human mandibular first and second molars were selected and divided into four groups. Radiographs with initial file inserted to working length were taken in all specimens with constant conditions. In group one, the preparations were made by Ni-Ti files and hand instrumentation technique. In group two, the preparation were made by stainless steel files and the same technique in group one, in group three preparation were made by Ni-Ti files and TEP-E10R reciprocal handpiece and in group four, the preparation were made by stainless steel files and the same handpiece in group three. Instrumentation technique in all four groups was crown down preparation. After finishing of the instrumentation in latter four groups, additional radiographs were taken while the master apical files [MAF] were inserted in the canals with the same constant conditions recorded for intial file radiographs. The MAF radiographs were compared with initial file radiographs for canal trans portation. The amount of dentin removal was also calculated by measuring instrumented surface in the final radiographs. Data were collected by SPSS10. One way ANOVA analysis was used to compare four groups and tukey test was used to compare couple groups. All of specimens showed degrees of transportation. Group two had the most mean degree of transportation that was significantly different from group one [P=0.001]. None of the groups had statistically significant difference between amount of dentin removed from canal walls [P=0.83]. Reciprocal handpices with NiTi files had acceptable results for canal preparation