玷污层及不同根管封闭剂对根管充填后根尖微渗漏的影响

目的:评估玷污层、根管封闭剂对根管充填后微渗漏的影响。方法:选择新鲜拔除的根尖发育完成的单根管人前牙,常规预备根管,随机分4组:A(AH-plus),B(Apexit),C(氧化锌丁香油糊剂),D(根管糊剂),各组内再分为1、2组,1组在充填前用170g/LEDTA和52.5g/L次氯酸钠溶液交替冲洗以去除玷污层,2组仅用52.5g/L次氯酸钠溶液冲洗,所有牙采用侧方加压法充填根管后,在冠方插入铜丝使其与牙胶接触,浸入生理盐水溶液中,在每牙与一不锈钢电极间加12V的直流电,观察40d,用单因素方差分析和LSD-t检验比较10、20、30、40d时的数据。结果:AH-plus、Apexit产生的微渗漏低于氧化锌丁香油糊剂、根管充填糊剂,而AH-plus又低于Apexit,去除玷污层使AH-plus产生低的微渗漏值。结论:AH-plus、Apexit的封闭能力优于氧化锌丁香油糊剂、根管充填糊剂,去除玷污层能增加AH-plus的封闭能力。

Effects of smear layer and root canal sealer on microleakage in root-filled teeth

AIM:To evaluate the effects of smear layer and root canal sealer on microleakage in root-filled teeth.METHODS:Freshly extracted human single-rooted teeth with closed apices and single root canal were used.All roots were instrumented with routine preparation technique.The teeth were randomly devided to 4 groups,different group with different sealers,A(AH-plus),B(Apexit),C(ZOE),D(CompoundThymol Cement).Tthen the teeth in each group were devided to 2 groups again.Prior to obturation,group 1 were flushed with 170g/L EDTA and 52.5g/L NaClO to remove the smear layer and group 2 were flushed with 52.5g/L NaClO only.All teeth were obturated with lateral condensation.Copper wire was placed in contact with the gutta-percha in each tooth.After immersion in normal saline solution,12v of direct current voltage was connected between each tooth and a stainlness electrode.The current flow in the circuit was observed for 40 days.One way ANOVA and LSD-t test were used to compare the data at time intervals of 10,20,30 and 40days.RESULTS:Significantly less microleakage occurred in AH-plus and Apexit than ZOE and Compound Thymol Cement.AH-plus exhibited less leakage than Apexit.Removed smear layer reduced the leakage of AH-plus.CONCLUSIONS:The sealing ability of AH-plus and Apexit was greater than the other sealers.Removing the smear layer can increase the sealing ability of AH-plus.