Comparison Of The Number Of Prepared Canals Leading To Defect Or Fracture In Two Biorace And Mtwo Rotary Systems In Mesiobuccal Canals Of Maxillary First Molars With Moderate Curvature

Background and Objective: cleaning and shaping of the root canal is done with a variety of manual and rotary instruments. The aim of this study was comparison of the number of instrumented root canals leading to defect or fracture in moderate curved canal in two systems: Biorace and MtwoMaterials and Methods in this exvivo study, 40 mesiobuccal root canals of extracted maxillary molars with mature apex and angles of curvature between 5 to 25 degrees were divided into two groups. Cleaning and shaping each group was done with one of the Biorace or Mtwo system. Working length in all groups was 13 mm. Instrumentation in each group started in the first canal with a set of instruments and was repeated in next canals with the same set, until there was a defect or fracture in one of the instruments. After recording the number of prepared canals leading to defect or fracture and the type of failure the failed instrument was substituted with the same instrument in size and taper and instrumentation continued until all 20 canals in each group were prepared. The data was analyzed using Chi square and fisher exact test.Findings: in Mtwo rotary system 3 files from 6 files fractured and in Biorace no file fractured.Conclusion: the canal preparation of the Mtwo system was defective or fracturing earlier than the Biorace rotary system, but it was found that statistical analysis didn’t show statistically significant differences.

کلیدواژه ها:

Mtwo rotary file ، Biorace rotary file ، fractured file