@article{TONG2017, 
author = {Fangli TONG and Qin YANG and Xiongqun CENG},
title = {In vitro evaluation of retreatment efficacy of Mtwo rotary instruments},
year = {2017},
journal = {Journal of Prevention and Treatment for Stomatological Diseases},
volume = {25},
number = {7},
pages = {426-429},
keywords = {Mtwo rotary instruments, Manual instruments, Root canal preparation, Root canal filling, Root canal retreatment},
url = {https://www.sciopen.com/article/10.12016/j.issn.2096-1456.2017.07.004},
doi = {10.12016/j.issn.2096-1456.2017.07.004},
abstract = {ObjectiveTo evaluate the efficacy of Mtwo rotary instruments during root canal retreatment.MethodsThirty 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 removed with Mtwo retreatment system and Mtwo basic instruments. Inmanual stainless group, the filling material were removed with manual instruments. The percentage of residual filling material was measured with image proplus softwareand the operating time was recorded. ResultsThe percentage of residual filling material in Mtwo group was significantly 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 significantly shorter than manual group.ConclusionMtwo rotary instruments can shorten the time of retreatment, neither of the groups can remove the filling material in oval root canal completely.}
}