根管偏移对充填材料封闭根管能力的影响

目的 :研究弯曲根管预备后的根管偏移对充填材料封闭根管能力的影响。方法 :选取 73颗下颌单根管前磨牙作为研究对象 ,其中弯根管牙 46颗 ,直根管牙 2 7颗。A组 2 3颗弯根管牙用Lightspeed器械预备根管 ,B组 2 3颗弯根管牙、C组 17颗直根管牙以及对照组牙用K锉预备根管 ,预备方法为逐步后退技术。使用双曝光X线技术和Ehrlich法测量根管偏移指数 (ATI)的大小。使用侧向加压技术充填所有根管后 ,用流体传输模型测量每个根管内微渗漏的量。结果 :A组中有 19%的根管发生根管偏移 ,B组中有 85 %的根管发生根管偏移 ,两组之间ATI的大小有高度显著性差异。当ATI大于 0 .3mm时 ,根管内微渗漏的发生率明显增加。结论 :弯曲根管预备中出现的根管偏移会削弱充填材料封闭根管的效果。

Effects of apical transportation on seal of root canal fillings.

Objective:This study is to investigate effects of apical transportation (AT) on the seal of root canal fillings.Methods:Human mandibular premolars with single, curved or straight canals were prepared with Lightspeed or step back technique.An AT index was determined using a double exposure radiographic technique and Ehrlich method.The prepared canals were obturated using lateral condensation of gutta percha.Leakage along the apical 3mm of root fillings was measured with a fluid transport model.Results:After K file preparation, AT occurred in 85% of the curved canals.After Lightspeed preparation,AT occurred only in 19% of the curved canals.The K file/curved canal group leaked statistically significantly more than the Lightspeed/curved canal group.The canals leaked more when ATI was more than 0.3mm.Conclusions:The occurrence of AT is a factor that negatively influnces the apical seal when curved canals are obturated by gutta percha using lateral condensation technique.