The effects of Ni-Ti instruments on the generation and distribution of root microcracks during the root canal preparation
GUO Ling-qiao
LAI Guo-qin
WANG Xiao-yi
Abstract：AIM:To compare the generation and distribution of root microcracks during the root canal prepara-tion with 3 kinds of Ni-Ti instruments. METHODS:64 extracted mandibular incisors were selected and randomly as-signed to 4 groups(n＝16). The incisors was left unprepared as the controls,in the remaining 3 groups were instru-mented with the ProTaper Universal(PTU),Twisted Files(TF)and Mtwosystem(MT)respectively up to size #25. Then the roots were sectioned horizontally at 3,6 and 9 mm from the apex and evaluated under a microscope. The gen-eration and distribution of root microcracks were observed and analyzed by using tchi-square test. RESULTS:In the group of control,PTU,TF and MT microcracks were observed in 0,11,3 and 10 of the tooth canals(PTU vs MT, P＞0.05;TF vs PTU or MT,P＜0.05). There no difference among the 4 sides at the section of 3 mm from the apex (P＞0.05),and microcracks of the buccolingual side were more than those of mesiodistal side at 6 mm and 9 mm sec-tions(P＜0.05). CONCLUSION:The Twisted File causes fewer root microcracks than the ProTaper Universal file and Mtwo file during the root canal preparation.In the root apical segment,the microcracks are evenly distributed,and in the middle and upper segments,cracks on the buccolingual sides are mor than on the mesiodistal sides.
Keywords：rootmicrocracksNi-Ti instrumentsroot canal preparation
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 356-359 )