中文摘要：

目的:比较S形根管经Reciproc和Mtwo两种机用镍钛器械预备后的形态对根管冲洗效果的影响。方法:40个S形树脂模拟根管,随机分为2组(n=20),分别使用Reciproc和Mtwo完成根管预备;使用30G侧方开口冲洗针头结合注射器,定速定量将蓝黑色墨汁注入预备后根管内,记录针头与根尖孔距离和气锁长度;使用25#/0.04锥度牙胶尖扰动方法排除气锁,记录气锁去除时间;抽取生理盐水对完全充盈后根管内的墨汁进行冲洗,记录冲洗后死水区长度。结果:Reciproc组针头与根尖孔距离为(4.276±0.221)mm,显著长于Mtwo组的(3.459±0.205)mm(P【0.05);Reciproc组气锁长度为(4.472±0.230)mm,显著长于Mtwo组的(3.668±0.217)mm(P【0.05)。Reciproc组气锁去除时间显著短于Mtwo组[(10.13±1.79)s对比(15.29±2.15)s,P【0.05]。Reciproc组冲洗后死水区长度亦显著小于Mtwo组[(1.351±0.142)mm对比(2.245±0.206)mm,P【0.05]。结论:Reciproc与Mtwo对S形根管预备后,根管形态上的差异影响根管冲洗的效果,Reciproc预备后的冲洗效果优于Mtwo。

英文摘要：

Objective: To evaluate effect of the morphology of simulated S-shaped root canals with Reciproc or Mtwo instruments on root canal irrigation. Methods: A total of 40 simulated S-shaped resin blocks were randomly divided into 2 groups (n=20), which was prepared by Reciproc or Mtwo. Blue ink was injected with constant speed and volume into the canals using 30G lateral opening syringe. hTe distance from needle tip to apex and vapor lock length were measured. A type of 25# 0.04 gutta-percha point was used to stir and remove the vapor lock. hTe time for removal of the vapor lock was recorded. Another syringe was used to inject saline into the canals and to measure the length of stagnant water. Results: hTe distance from needle tip to apex in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.276 ± 0.221) mm vs (3.459 ± 0.205) mm,P<0.05]. The vapor lock length in the Reciproc group was signiifcantly longer than that in the Mtwo group [(4.472 ± 0.230) mm vs (3.668±0.217) mm,P<0.05]. hTe time to remove vapor lock was signiifcantly shorter in the Reciproc group than that in the Mtwo group [(10.13 ± 1.79) s vs (15.29 ± 2.15) s,P<0.05]. The length of stagnant water was also shorter in the Reciproc group than that in the Mtwo group[(1.351 ± 0.142) mm vs (2.245 ± 0.206) mm,P<0.05]. Conclusion: hTe morphology of S-shaped root canal affects the root canal irrigation. hTe effect of root canal irrigated by Reciproc is better than that by Mtwo.