去除玷污层对根管微渗漏影响的实验研究

Experimental research of effect of removal of the smear layer on apical microleakage

目的 :评价去除玷污层对根管充填材料密封性能的影响。方法 :选取 6 0个新鲜拔除的人单根管牙 ,在釉牙骨质界处切除牙冠。将所有牙根随机分为 3组 ,每组 2 0个。分别用根管充填糊剂加牙胶尖、Vitapex糊剂加牙胶尖和Thermafil糊剂热熔牙胶充填根管 ;每组中有 10个牙根根管预备时保留玷污层 ,另外10个去除玷污层。用印度墨水染色法对比研究去除玷污层对根管充填材料密封性能的影响。结果 :牙胶尖加根管充填糊剂组中 ,保留和去除玷污层组的染色线长度均值分别为 :3.36± 0 .4 2mm、3.4 2± 0 .6 5mm ;Vitapex加牙胶尖组中 ,染色线长度均值分别为 :2 .0 9± 0 .19mm、1.70± 0 .2 2mm ;Thermafil热熔牙胶组中 ,染色线长度均值分别为 :1.0 5± 0 .37mm、0 .5 6± 0 .11mm。统计学分析发现 :3个实验组中 ,去除玷污层或保留玷污层对根管微渗漏影响的统计学差异均不显著 (P >0 .0 5 )。结论

AIM:To evaluate the effect of removal of the smear layer on apical microleakage.METHODS:Freshly extracted sixty single-rooted human teeth were selected for this experiment and cut at the amelocemental junction using a diamond disk under water coolant.All roots were randomly divided into three groups of 20 roots each.The smear layers of 10 roots of each group were removed by 150 g/L EDTA after root canal preparation.The roots of three groups were filled with zinc oxide-eugenol paste+gutta-percha (Group A),Vitapex+gutta-percha (Group B) and Thermafil(Group C),respectively.Apical microleakage was evaluated with Indian Ink dye penetration.RESULTS:The results showed that mean depths of microleakage in root canals with or without the smear layer in Group A,B and C were 3.36±0.42 mm,3.42±0.65 mm,2.09±0.19 mm,1.70±0.22 mm,1.05±0.37 mm and 0.56±0.11 mm respectively.No significant difference was found between root canals with or without smear layer in all three groups(P>0.05). CONCLUSION:Removal of the smear layer had no effect on the sealing ability of root canal materials.