Comparison of effects of different reciprocal angles on the amountapically extruded debris using reciproc R25 rotary file sistem

One of the factors affecting success in root canal treatment is practicing the chemo-mechanical shaping in an appropriate way. Today, there are various rotary file systems on the market with different features and working principles. It has been an object of interest for clinicians that how much debris these files extrude apically during the mechanical enlargement. This study aims to compare the amounts of apical extrusion of debris via using Recıproc (R25) file with different angles. Material and Method: In this research, sixty extracted mandibular premolars with single root, single canal and single apical foramen have been used. Specimens, the working length of which were determined by a stainless steel 10-K file, were randomly divided into three experimental groups groups (n=20). Group 1: Reciproc R25 (VDW, Munich, Germany) 150° CCW (Counterclockwise) - 30° CW (Clockwise), Group 2: 180° CCW - 60° CW, Group 3: 210° CCW - 90° CW angles of rotation were used to shape the root canals. Root canals were irrigated with 10 ml distiled water using syringe pump. Using the experimental model described by Bürklein et al., the extruded debris was collected into Eppendorf tubes. All of the tubes were incubated at 70 °C for 3 days, to evaporate the distiled water. The Eppendorf tubes, before and after the process, were weighed on a microbalance with accuracy to 10-6 the amount of accumulated debris was assessed. Results: While researching the normal distribution of variables, Shapiro-Wilk test was used due to number of units. The significance level was set at p<0.05 to interpret the results. During the examination of differences among the groups, the Kruskal-Wallis H test was used in case the variables were not normally distributed. There was no statistically significant difference among the groups as regards the final measurement values (p>0.05). Nevertheless, the highest amount of extrusion of debris was detected in group 2 (180° °CCW - 60° °CW). Conclusion: According to the results of this study, changing the angles in R25 rotary file systems working with reciprocal motion had no significant effect on the amount of apical extrusion of debris. Keywords: Apical extrusion; debris; Recıproc R25.