【摘要】 目的探讨上颌前牙根管预备后距根尖4mm处根管壁的最小厚度,为临床预备桩腔末端的宽度提供理论依据。方法离体直单根管上前牙60个,随机分为3组(n=20)进行根管预备,A组:不锈钢根管锉常规法;B组:G型钻根管冠部预处理+不锈钢根管锉常规法;C组:手用ProTaper镍钛根管锉冠向下法。所有牙齿用金刚砂片分别在距根尖4mm处和釉牙骨质界处截断牙根,截断面垂直于根管。用游标卡尺测量断面根管近中壁、远中壁最薄处厚度。结果三种方法根管预备后距根尖4mm处和釉牙骨质界处剩余根管壁厚度均数都大于1mm。釉牙骨质界处与距根尖4mm处剩余根管壁厚度之间行直线相关分析,只有B组釉牙骨质界处与距根尖4mm处远中壁剩余根管壁厚度之间存在线性相关,其它组之间均不存在线性相关。结论对于大多数病例,经三种方法根管预备后,推荐使用3#P型钻预备上颌前牙桩腔末端。更多还原

【Abstract】 Objective To investigate the residual dentin thickness in upper anterior teeth at 4mm short of the apex and provide theoretical basis for the width of post space end preparation.Methods 60 upper anterior teeth with straight root canals were randomly assigned to 3 groups (n=20) and prepared,Group A:stainless steel file conventional root canal preparation technique; Group B:Gate-Glidden drill coronal preflaring + stainless steel file conventional root canal preparation technique; Group C:ProTaper for hand crown-down technique. The roots were cut horizontally at cement-enamel junction and 4mm short of the apex. The minimum width of residual root was measured on mesial and distal wall by a vernier caliper gauge.Results The minimum width means of residual root among 3 groups were larger than 1mm after root canal preparation. Linear correlation analysis showed that there were no correlation between the residual dentin thickness at cement-enamel junction and 4mm short of the apex besides B group distal wall.Conclusion 3# peeso reamer was recommended to prepare post space end in upper anterior teeth after root canal preparation in most cases.更多还原