不同根管预备技术与充填技术对弯曲根管封闭性能影响的实验研究

目的 探讨根管预备技术和根管充填技术对中重度弯曲根管治疗后根管封闭性的影响。方法 选取中重度弯曲单根管前磨牙60颗，随机分为A、B、C、D四个实验组(各12颗)及阳性对照E组和阴性对照F组(各6颗)。实验组分别用ProTaper/crown-down法、K锉逐步后退法对根管进行预备(各24颗牙)，每种预备方法分别行冷侧方加压加AH-plus糊剂和热牙胶垂直加压加AH-plus糊剂充填根管(各12颗牙)，建立微渗漏模型，应用邻甲苯胺(O-TB)法测量其葡萄糖浓度。结果 A、B、C、D四个组均测得葡萄糖浓度分别为：(3.69±1.01)mmol/L、(4.59±0.98)mmol/L、(2.86±0.82)mmol/L、(3.70±0.62)mmol/L， E组测得葡萄糖浓度最高为(5.89±1.69)mmol/L，F组没有测得葡萄糖浓度，在相同的充填技术下，ProTaper/crown-down法和K锉逐步后退法之间的微渗漏值差异有统计学意义(P＜0.05)；在相同的预备方法下，热牙胶充填技术和冷测压充填技术之间的微渗漏值差异有统计学意义(P＜0.05)。结论 应用ProTaper/crown-down法加热牙胶充填中重度弯曲根管，有利于提高中重度弯曲根管充填后根管的封闭能力。

Effects of different preparation and obturation techniques on the sealing of root fillings in curved teeth in vitro

Objective To explore the effects of preparation technique and obturation technique on the sealing of root fillings in moderately and severely curved root canals. Methods Sixty curved human premolar teeth were randomly divided into four experimental groups (A、B、C、D) and two control groups(E、F)， in which each experimental group included twelve samples and each control group included six samples. Groups A and C were prepared with the ProTaper/crown-down technique. Groups B and D were prepared with the step-down technique. Groups A and B were obturated with AH-plus sealer by lateral condensation and group C and D were obturated with AH-plus sealer by vertical condensation. We measured the leakage by the concentration of glucose in the apical reservoir along the root filling with O-TB method. Results The concentrations of glucoes in the four experimental groups were 3.69±1.01、4.59±0.98、2.86±0.82 and 3.70±0.62mmol/L, respectively, while the highest concentration was in group E (5.89±1.69mmol/L). No glucose was detected in group F. The difference between the step-back and ProTaper/crown-down technique, combined with the same obturation technique, was significant (P＜0.05). The difference between the vertical and lateral condensation technique was significant when the same preparation technique was applied altogether (P＜0.05).Conclusion The sealing ability of ProTaper/crown-down technique and vertical condensation technique is the best for curved teeth in vitro.