【作者】 梁斌；

【导师】 高义军；

【作者基本信息】 中南大学 ， 口腔临床医学， 2011， 硕士

【摘要】 目的：评价机用Mtwo镍钛系统在根管再治疗中的性能及再治疗对根尖微渗漏的影响。方法：选取34颗正畸拔除的双根管前磨牙,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组步退法预备根管,牙胶尖配合糊剂行冷牙胶侧方加压充填,C组为首次根管治疗组,每组10颗牙,20个根管。30d后将这3组均随机分为2组,分别用手用不锈钢器械及Mtwo镍钛器械清理预备根管,手用不锈钢器械组用0.02锥度40#牙胶尖做主尖配合AH-Plus糊剂行冷牙胶侧方加压充填；Mtwo镍钛器械组用0.06锥度25#做主尖配合AH-Plus糊剂行冷牙胶侧方加压充填。30d后,对离体牙进行染色,测量根尖微渗漏。记录和比较各组的操作时间、器械折损、根管再通及根尖微渗漏等情况。结果：1.在塑化、根充再治疗组及首次治疗组的比较中发现,Mtwo镍钛系统各组的操作时间均较手用不锈钢器械各组少(P<0.05)；2.在Mtwo镍钛系统组及手用不锈钢器械组,单纯预备根管需要的时间最少,去除根管内塑化物需要的时间最多,去除根管内牙胶使用的时间居中(P<0.05)；3.在塑化、根充再治疗组及首次治疗组中,Mtwo镍钛系统组的根尖微渗漏较手用不锈钢器械组小(P<0.05)；4.在Mtwo镍钛系统组和手用不锈钢器械组中,塑化再治疗组和根充再治疗组的根尖微渗漏无明显差异(P>0.05),再治疗组的根尖微渗漏较首次治疗组大,有统计学差异(P<0.05)。结论：1.Mtwo镍钛器械去除根管内充填物及预备根管的操作时间较手用不锈钢器械少；2.Mtwo镍钛系统各组的根尖微渗漏较手用不锈钢器械各组的根尖微渗漏小；3.在再治疗根管可以再通的情况下,首次治疗方法对再治疗根管的根尖微渗漏无明显影响。更多还原

【Abstract】 Objective:Evaluation of the quality of Mtwo NiTi instruments system in root canal retreatment and the effects of root canal retreatment on apical microleakage.Method:Thirty-four extracted premolars teeth (68 root canals) were collected, they were randomly divided into 3 experimental groups of 10 teeth each, in addition to a positive and negative control group of 2 teeth each.Group A:obturated with FR phenolaldehy deagent;Group B prepared with step-back technique and filled with gutta-percha cone and sealer; Group C:done nothing to the teeth until next step.After 30 days, every group were divided into 2 groups randomly:stainless steel hand files group and Mtwo NiTi instruments group. Stainless steel hand files group was filled with 0.02 tapered angle 40# master cones and AH-Plus obturated with cold lateral condensation. Mtwo NiTi instruments group was filled with 0.06 tapered angle 25# master cones and AH-Plus obturated with cold lateral condensation. After 30 days,the microleakge of the 4 groups was evaluated by dyeing.The operating time, broken files, negotiated canals and the microleakge length were recorded.Results:1. In Group A、B and C, the mean operating time of Mtwo NiTi instruments group was significantly shorter than stainless steel hand files group (P<0.05).2. In stainless steel hand files group and Mtwo NiTi instruments group, the mean operating time of Group C was significantly shorter than Group B, the mean operating time of Group B was significantly shorter than Group A (P<0.05).3. In Group A、B and C, the mean apical microleakage length of Mtwo NiTi instruments group was significantly shorter than stainless steel hand files group(P<0.05).4. In stainless steel hand files group and Mtwo NiTi instruments group,there was no significant difference between Group A and B (P>0.05). the mean apical microleakage length of Group C was significantly shorter than Group A (P＜0.05),the mean apical microleakage length of Group C was significantly shorter than Group B (P<0.05).Conclusion:1. The operating time of Mtwo NiTi instruments group was shorter than stainless steel hand files group.2. The apical microleakage length of Mtwo NiTi instruments group was shorter than stainless steel hand files group.3. If the root canal could be negotiated successfully, the kind of the first treatment do not affect the apical microleakage of it.更多还原