Effect of Instrumentation Techniques and Kinematics on Apical Extrusion of Debris: An In Vitro Study

Aim: To evaluate the effect of instrumentation kinematics on debris extrusion by comparing the amount of apically extruded debris after canal preparation using ProTaper next in continuous rotation as well as forward reciprocating motion and WaveOne gold in reverse reciprocating motion.

Materials and methods: We randomly divided ninety buccal roots of maxillary bicuspids with fully formed apices into three groups. After achieving the coronal access, the patency of the root canals was established with a size 10 K file. The canals were then instrumented using ProTaper next in continuous rotation or in a forward reciprocating motion and WaveOne gold in reverse reciprocating motion. Eppendorf tubes were used to collect the debris extruded through the apical foramen. The tubes were placed in a -80° freezer for 8 hours and then in a lyophilizer for 24 hours. The quantity of the apically extruded debris was assessed by subtracting the weights of Eppendorf tubes before and after instrumentation. The analysis was done using a one-way ANOVA test and the Bonferroni test to compare the groups.

Results: The mean weight of extruded debris with WaveOne gold in reverse reciprocation was significantly lower than ProTaper next in forward reciprocation and ProTaper next in continuous rotation (p value = <0.001).

Conclusion: WaveOne gold in reverse reciprocation was associated with a significantly lower amount of apical extrusion of debris than ProTaper next rotary files in forward reciprocation and continuous rotation.

Clinical significance: According to the results of this study, reciprocating instrumentation technique was associated with a less amount of debris extrusion compared to continuous rotation.