In vitro evaluation of retreatment efficacy of Mtwo rotary instruments

Abstract

Objective To evaluate the efficacy of Mtwo rotary instruments during root canal retreatment. Meth⁃ ods Thirty mandibular premolars with oval root canal were prepared with ProTaper rotary instruments and obturated with lateral condensation method. The samples were divided into 2 groups. In Mtwo group, the filling materials were re⁃ moved with Mtwo retreatment system and Mtwo basic instruments. Inmanual stainless group, the filling material were re⁃ moved with manual instruments. The percentage of residual filling material was measured with image proplus software and the operating time was recorded. Results The percentage of residual filling material in Mtwo group was signifi⁃ cantly lower than manual group in middle third, but the opposite result can be found in the coronal third. In the whole canal, no significant difference was found between the two groups. The mean operating time in Mtwo group was signifi⁃ cantly shorter than manual group. Conclusion Mtwo rotary instruments can shorten the time of retreatment, neither of the groups can remove the filling material in oval root canal completely.

Keywords

• Mtwo rotary instruments
• Manual instruments
• Root canal preparation
• Root canal filling
• Root canal retreatment