大锥度牙胶尖与两种镍钛机动根管预备锉的匹配性研究

目的评价大锥度牙胶尖与两种机动镍钛根管预备锉的匹配性。方法选择40只离体后牙根管,根据初尖锉的号码和近远中向根管弯曲度分为2组,分别以ProTaper和ProFile两种机动镍钛根管锉完成根管预备,插入大锥度牙胶尖进行试尖,比较两者的匹配性。结果ProTaper F1、F2、F3与0.06锥度/20、253、0号牙胶尖的匹配率分别为80%、88%、92%,均较同锥度大1号的牙胶尖匹配率高,差异有显著性(P<0.01)。ProFile 0.06锥度/30号和40号与0.04锥度同号牙胶尖的匹配率最高,分别为83%和96%,其次是0.06锥度小1号牙胶尖,而与0.06锥度同号牙胶尖匹配率最低,分别为35%和25%,3者间差异有显著性(P<0.01)。结论大锥度镍钛机动器械预备的根管,与主尖锉同号而锥度减小或锥度相同且小1号的大锥度牙胶尖有良好的匹配性。

Study of fitting of greater taper gutta percha cones in root canals prepared with two kinds of nickel-titanium rotary instruments

Objective To evaluate the fitting of greater taper gutta percha(GP) cones in root canals prepared with two kinds of nickel-titanium(niti) rotary instruments.Methods 40 canals of extracted posterior teeth were divided into two groups according to the size of initial apical file and the canal curvature in mesio-distal direction.The two groups were prepared with either ProTaper or ProFile niti rotary instruments,after which cone-fitting was carried out by inserting the greater taper GP cones of different sizes/tapers into the prepared canal.Results In canals prepared to ProTaper F1,F2 and F3,the fitting rates of size 20,25 and 30/0.06 taper GP cones were 80%,88% and 92%,respectively,which were higher than those of GP cones with one size larger than the Protaper finishing files but of the same taper.The differences were statistically significant(P<0.01).In canals prepared to 0.06 taper ProFile size 30 and 40,the highest fitting rates were achieved with the same size/0.04 taper GP cones,which were 83% and 96%,respectively.The fitting rates with GP cones of one size smaller/0.06 taper ranked secondly,the lowest fitting rates came to the GP cones of the same size and same taper,which were 35% and 25%,respectively.The differences were statistically significant(P<0.01).Conclusion In canals prepared with greater taper niti rotary instruments,greater taper GP cones with same size/smaller taper or same taper/smaller size as compared with the master apical files fitted well as master GP cones.