Mtwo镍钛系统在根管再治疗中对根尖微渗漏的影响

Effects of Mtwo NiTi instruments system in root canal retreatment on apical microleakage

目的评价Mtwo镍钛系统在根管再治疗中对根尖微渗漏的影响。方法选取34颗正畸拔除双根管前磨牙,随机选4颗设为对照组,2颗阴性对照组和2颗阳性对照组,其余30颗随机分为3组:A组行塑化治疗,B组行冷牙胶侧方加压根管充填,C组为首次根管治疗组,每组10颗牙,20个根管。恒温恒湿条件下保存4周后将这3组中的每一个组均随机分为2组,分别用手用不锈钢器械及Mtwo镍钛系统清理预备根管,之后均行冷牙胶侧方加压充填。再在恒温恒湿条件下保存4周,之后对离体牙进行染色7 d,之后测量根尖微渗漏。记录和比较各组根尖微渗漏情况。结果①在A、B、C三组各自的组内比较中发现,使用Mtwo镍钛系统处理的根管的根尖微渗漏较使用手用不锈钢器械处理的小(P<0.05);②在使用Mtwo镍钛系统时,A、B、C三组的组间比较显示:A、B组间根尖微渗漏差异无统计学意义(P>0.05),C组的根尖微渗漏较A组和B组小,有统计学差异(P<0.05);在使用手用不锈钢器械时,结果相同。结论①Mtwo镍钛系统处理根管产生的根尖微渗漏较手用不锈钢器械的小;②在再治疗根管可以再通的情况下,首次治疗的方法对再治疗根管的根尖微渗漏无明显影响。

Objective To explore the effects of Mtwo NiTi instruments system in root canal retreatment on apical microleakage. Methods Thirty-four extracted premolar teeth were collected, and randomly divided into 3 experimental groups （n = 10 in each group）, positive control group（ n = 2） and negative control group（ n = 2）. The teeth were obturated with FR phenolaldehy deagent in group A, filled with gutta-percha cone and sealer in group B, and were done nothing until the next step in group C. After the teeth were kept at the constant temperature and humidity for 4 weeks, every group was divided into 2 subgroups randomly ： stainless steel hand files group and Mtwo NiTi instruments group. Then all teeth were filled with gutta-percha cone and sealer, and kept at the constant temperature and humidity for 4 weeks. The microleakage was evaluated by dyeing for 7 d. The microleakage length was recorded. Results （1）In groups A, B and C, the mean apical microleakage length in Mtwo NiTi instruments group was significantly shorter than in stainless steel hand files group （P 〈 0.05 ）. （2）In stainless steel hand files group and Mtwo NiTi instruments group, there was no significant difference in mi- croleakage length between groups A and B （ P 〉 0.05 ）. The mean apical microleakage length in group C was siguificantly shorter than those in group A and group B （ P 〈 0. 05 ）. Conclusion （1）The apical microleakage length of Mtwo NiTi instruments is shorter than that of stainless steel hand files. （2）When the root canal could be negotiated successfully, the way of the first treatment do not influence the apical microleakage.