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目的评价Mtwo机用镍钛器械用于乳磨牙根管治疗的临床效果。方法选择2013年1—12月南京大学医学院附属口腔医院儿童口腔科门诊就诊的103名4~8岁患儿,应用两种不同预备方法和器械对160颗乳磨牙行根管治疗。其中80颗诊断为急、慢性牙髓炎（P组）,80颗诊断为急、慢性根尖周炎（A组）,P、A每组再随机分为试验组（E组）和对照组（C组）,每组40颗,试验组用Mtwo机用镍钛器械预备根管,对照组用GG钻和不锈钢K锉以改良步退法预备根管。根据操作时间、约诊间痛发生率评价临床效果。结果 PE组与PC组根管预备平均时间分别为（308.5±60.4）和（492.0±48.5）s（P〈0.05）;约诊间痛发生率分别为5.0%和2.5%（P〉0.05）。AE组与AC组根管预备平均时间分别为（379.8±61.3）和（593.8±79.7）s（P〈0.05）;约诊间痛发生率分别为7.5%和20.0%（P〉0.05）。结论 Mtwo机用镍钛根管预备器械能够提高乳磨牙根管治疗的效率和效果。

Clinical application of Mtwo rotary nickel-titanium instruments in root canal therapy of primary molars

ObjectiveTo evaluate the clinical effect of Mtwo rotary nickel-titanium（Ni Ti）instruments on root canal therapy of primary molars.MethodsEighty teeth with acute or chronic pulpitis（Group P）and 80 teeth with acute or chronic apical periodontitis（Group A）of 103 patients aged 4 ~ 8 years were collected. Group P and A were randomly divided into experimental group（E）and control group（C）respectively.Mtwo rotary Ni Ti instruments were used in experimental groups,while modified step-back technique with Gates-Glidden drills were used in control groups. The operation time and the rate of endodontic interappointment pain were observed.ResultsThe average time（sec）for root canal preparation in groups PE and PC were（308.5 ± 60.4）and（492.0 ± 48.5）s（P〈0.05）,the interappointment pain rates were5.0% and 2.5%（P〉0.05）respectively. The average time for root canal preparation in groups AE and AC were（379.8 ±61.3）and（593.8 ± 79.7）s（P〈0.05）;the interappointment pain rates were 7.5% and 20.0%（P〉0.05）respectively.ConclusionMtwo rotary Ni Ti instrument is efficient and comfortable for root canal preparation of primary molars.