مقایسه آزمایشگاهی کارایی روشهای چرخشی Profile، Protaper،  Flex Master و دستی NiTi K-File در آماده‌سازی کانال ریشه

Statement of Problem: Root canal cleaning and shaping are important steps in endodontic therapy. In order to develop better techniques, new instruments are constantly designed and delivered to the market.Purpose: The aim of the present study was to compare the effectiveness of one manual with three rotary root canal instrumentations techniques.Materials and Methods: In this in-vitro study, 80 mesial roots of freshly extracted human mandibular molars were divided in to four groups equally and prepared by one of the following instrumentation methods profile NiTi rotary system, Protaper NiTi rotary system, Flex Master NiTi rotary system and hand NiTi K-file instrumentation. In each root one of the canals was instrumented and the other was used as control.After decalcification, cross sections at 3mm and 5mm of apical portion were prepared and examined for remaining debris, predentin and smooth walls under light microscope. The data were analyzed by Kxuskal-Wallis test.Results: Significantly less debris was found at 3mm cross- section using protaper and Flex Master techniques (P<0.05). No significant differences were found at 5mm cross section. Also no significant differences were observed for remaining predentin at all regions. Significantly more smooth walls were found at both regions using protaper technique (P<0.05).Conclusion: The protaper technique employed in this study resulted in cleaner root cana! walls than theother techniques.