【摘要】 目的:使用锥形束计算机断层扫描(cone beam computed tomography, CBCT)对比Protaper Universal Retreatment(PTUR)与Reciproc Blue(RB)、Re Treaty(RT)再治疗机用镍钛锉在椭圆形弯曲根管中去除充填材料的效果及中心定位能力，并使用微计算机断层扫描(Micro-CT)和扫描电子显微镜进一步评估使用传统注射器冲洗(classic syringe-based irrigation, CSI)、被动超声冲洗(passive ultrasonic irrigation, PUI)、和XP4辅助锉(XP4)对剩余根充材料及玷污层的清除效果。方法:(1)再治疗机用镍钛锉实验：选取45颗单根管离体前磨牙，完善根管充填后，随机分为PTUR组与RB组、RT组，3组(n=15)进行处理记录剩余根充材料体积和根管偏移量。(2)辅助冲洗实验：选取45颗单根管离体前磨牙，RB锉再治疗后，随机分为CSI组、PUI组和XP4组，3组(n=15)进行处理记录剩余的根充材料体积及根管内壁玷污层评分。结果:(1)3组再治疗镍钛锉在去除根充物效果方面无显著差异(P=0.620);距根尖2 mm处，RB组根管偏移量小于PTUR组(P=0.027);(2)与CSI组和PUI组相比，XP4组去除了更多的根管充填材料(P<0.001);在根中和根尖三分之一处，XP4组对玷污层的清洁效果显著优于CSI组(P<0.05)。结论:PTUR、RB和RT锉适用于椭圆形弯曲根管的再治疗。与PUI和CSI相比，XP4显著提升了镍钛机用器械再治疗后残留根充材料和玷污层的去除效果。更多还原

【Abstract】 Objective: To compare the effect and centering ability of Protaper Universal Retreatment(PTUR), Reciproc Blue(RB), and Re Treaty(RT) nickel-titanium files in oval curved root canals using cone beam computed tomography(CBCT). Micro-computed tomography and scanning electron microscopy were also utilized to evaluate the effectiveness of classic syringe-based irrigation(CSI), passive ultrasonic irrigation(PUI), and the XP4 auxiliary file(XP4) in removing residual root filling materials and the smear layer. Methods:(1) Retreatment with Nickel-Titanium Files: Forty-five ex vivo single-root canal premolars, which had undergone complete root canal filling, were selected and randomly divided into three groups(n=15): PTUR, RB, and RT. The volume of remaining root filling material and any root canal deviation were recorded for each group.(2) Auxiliary irrigation experiment: Following retreatment with RB, another set of 45 ex vivo single-root canal premolars were randomly divided into three groups(n=15): CSI, PUI, and XP4. For each group, the volume of remaining root filling material and the score of the smear layer on the inner wall of the root canal were recorded. Results:(1) There was no significant difference in the volume of remaining root filling material between the three groups of re-treated nickel-titanium instruments(P=0.620). At 2 mm from the root apex, the apical transportation offset of the RB group was significantly smaller than that of the PTUR group(P=0.027).(2) Compared with CSI and PUI, XP4 removed significantly more root canal filling material(P<0.001). In the middle and apical third of the root, the cleaning effect of the XP4 group on the smear layer was significantly better than that of the CSI group(P<0.05). Conclusion: The PTUR, RB, and RT file systems are all suitable for the retreatment of oval curved root canals. Compared with PUI and CSI, XP4 significantly improves the removal of residual root filling material and smear layer after reprocessing with nickel-titanium mechanical instruments.更多还原