مقايسه ميانگين خروج اپيكالي دبري در درمان ريشه با استفاده از وسايل چرخشي نيكل تيتانيوم و فايلهاي k دستي نيكل تيتانيوم به روش Crown Down Pressureless به صورت in vitro

In vitro comparison of apical extrusion of debris using Nickle Titanium Rotary and Hand K- file instruments by crown down pressureless technique

Background & Aim . Extrusion of debris through apical foramen during instrumentation results in inflammation, pain and delayed healing. Thus, performing an instrumentation technique with minimum debris extrusion is preferred. The purpose of this study was to compare debris extrusion through apical foramen using Nickel Titanium rotary versus hand K- file instrumentation. Methods & Materials. Eighty extracted mandibular molar teeth (with separate orifices, canals and apical foramens in mesial root) were randomly divided into two groups. Teeth in group 1 were instrumented with rotary profile system: and in group 2 with hand Niti K - file using crown down pressureless technique. Mean dry weight of apically extruded debris was compared by t- student analysis in two groups. Results: The mean weight of apically extruded bebris was 1.05 mg in Rotary instrumentation and 1.33 mg in Hand filing. Conclusion. Although debris extrusion in Rotary system is less than Hand instrumentation, there was no statistical difference between two groups. Probably the less debris extrusion in Rotary technique is due to the more taper of these files and preflaring compared to Hand files. Thus, if the crown down technique is used, the debris extrusion with hand and rotary instrumentation are approximately similar.