Influence of Instrument Application on Extruded Debris in instrumentation Techniques

Objectives: To assess the influence of the number of applications on apical extrusion of debris in conventional and two rotary instrumentation techniques (ProFile and FlexMaster).

Methods: In this in vitro study, 75 extracted single-rooted human mandibular premolars with curvature between 0-10 degrees were selected and divided into three groups of 25 teeth each. All teeth were shortened to length of 15 mm by cutting the crown. Group H was prepared by hand step back technique, group P was prepared by ProFile system and group F was prepared by FlexMaster system. The number of applications was according to the manufacturer recommendation. For collection of debris, vials containing distilled water were used that were weighed before preparation by 0.0001 digital balance. To be sure about the purity of distilled water, two vials containing distilled water were used as control groups that dried and weighed in similar conditions to the specimen vials.

At the end of canal preparation, vials were completely dried and weighted again. The difference between the weigh of vials in two stages, was the weigh of debris extruded from apical foramen. The mean weigh of debris in various numbers of applications within each system was compared by one–way variance analysis.

Results: In comparison the various numbers of applications in each system, it was noted that only in ProFile system, with increasing number of applications, the quantity of debris extruded was reduced.

Conclusion: Unused ProFile instruments induce more extrusion of debris from apical foramen than used instruments.