再治疗根管再预备过程对根管壁损伤的影响

Influence of root canal retreatment procedures on the appearance of defects on the root canal walls

目的研究再治疗术根管再预备对根管壁损伤的影响。方法 160颗正畸拔除的前磨牙随机分为2组,各80颗,分别在拔除1个月(A组),半年后(B组)行根管治疗、再治疗;A组再随机分为根管治疗组(A1组)再治疗组(A2组),每组40颗,B组同样分为根管治疗组(B1组)再治疗组(B2组);A2和B2组又分为单独Pro Taper再治疗锉组(A21、B21)、Pro Taper再治疗锉辅助使用氯仿组(A22、B22)。牙根在显微镜下切断并检查。结果再治疗组的根管壁损伤明显高于根管治疗组;与Pro Taper再治疗锉单独使用比较,辅助使用氯仿组有明显的差异,使用氯仿可以减少再预备过程对根管壁的损伤。结论根管再治疗会比根管治疗造成更多的根管损伤。当评估根管再治疗时,应考虑牙壁损伤的潜在风险。

Objective To explore the influence of root canal retreatment procedures on the appearance of defects on the root canal walls. Methods One hundred and sixty premolars extracted for orthodontics were randomly divided into two groups with 80 in each group. They were treated and retreated a month（ A group） and half a year（ B group） after extraction. Forty teeth（ A1 group） in A group were treated and the other 40（ A2 group） were retreated at random,and B group was divided into B1 group and B2 group in the same way. Among retreated teeth,twenty teeth filling materials were removed by Pro Taper retreatment files only（ A21 group,B21 group） and the other twenty teeth were removed by Pro Taper retreatment files with chloroform（ A22 group,B22 group）. Roots were then sectioned and inspected under a microscope. Results Retreatment groups showed significantly more defects than the initial treatment group.There was difference in the appearance of defects after retreatment between Pro Taper retreatment files only group and chloroform-supplied group. Conclusions Retreatment procedures result in more defects than initial treatment. When assessing the outcomes of endodontic retreatment,the substantial damage to the root canal walls should be considered.