Evaluation of the effect of different nickel-titanium root canal files with reciprocal and rotational movement on the amount of apical debris extrusion

ABSTRACT Introduction and Objective: Root canal shaping is one factor that affects the success of root canal treatment. Differences in kinematics, metallurgical properties, design, and the number of files between file systems used in canal shaping affect the amount of apically extruded debris. The aim of this in vitro study was to compare the amount of apically extruded debris using TruNatomy, Reciproc, and Mtwo rotary file systems. Materials and Methods: In our study, 45 mandibular human incisors were included. Teeth with a canal inclination <10° (according to Schneider) were selected. The specimens were randomly distributed into three balanced groups (n =15): TRN (TruNatomy), RC (Reciproc), and MT (Mtwo). The canal lengths of the teeth were measured with a 10 K hand file, and the working lengths were recorded as 1 mm shorter than the measured length. The root canal working lengths were standardized to 18 mm by abrading the teeth occlusal. Root canals were shaped with TRN, RC, and MT file systems. All rotary file systems were used by a single operator according to the manufacturer's instructions. The amount of debris was measured using the experimental apparatus. The same irrigation procedure was applied to each tooth in the groups, and an equal amount of distilled water was used. The tubes were kept in an incubator at 70oC for five days to evaporate the distilled water in the Eppendorf tubes. The empty weights of the Eppendorf tubes and the weights of the tubes after removal from the incubator were measured with a 10-4 g precision balance. The amount of overflowing debris was calculated by recording the difference between weights.4 Results: The normality test of the data was analyzed by the Shapiro–Wilk test, and the statistical difference between the study groups regarding debris amount was determined by the Kruskal–Wallis H-test. At least one group was found to be different in terms of debris amount (p < 0.05). In case of significant differences in the Kruskal– Wallis H-test, the different paired groups were determined by the post hoc multiple comparison tests. There was a statistical difference between TRN and MT (p < 0.05). TRN and RC also showed a statistical difference (p < 0.05). RC and MT had no statistical difference (p > 0.05). Conclusion: In our study, all file systems extruded debris from the apical part of the root canal. TRN was the file that produced the lowest amount of apically extruded debris that is clinically acceptable. Keywords: Apical debris extrusion, Mtwo, Reciproc, root canal shaping, TruNatomy