不同长度的玻璃纤维桩修复对下颌前磨牙抗折强度的影响

摘要

Objective To compare the influence of different glass - fiber post lengths on teeth fracture resistance.Metbods Thirty extracted human mandible premolars were endodontically treated after being cut off the crowns from the cemento - enamel junction.The teeth were randomly and equally divided into A, B,C groups which were post lengths of 5mm ( shorter than 1/1 clinical crown length) ,7mm ( 1/1 clinical crown length) , and 9mm ( longer than 1/1 clinical crown length) respectively.And then, all of them were restored with resin cores and metal crowns.All the teeth were fixed in a umversal text machine after embedded in acrylic resin blocks,which were tested for the fracture resistance,and recorded the counts and observed the fracture mode.Results Fracture resistance of group A of restoration was significantly lower than that of B group and C group (P ＜0.05).Fracture resistances of group B and C,however,were not s]gnificantly different ( P ＞ 0.05 ) .Conclusion Glass fiber post lengths should not be shorter than clinical crowns when we use thcm to restore dcntal defects.%目的 比较玻璃纤维桩长度对牙齿抗折强度的影响.方法 选择30颗近期因正畸完整拔除的下颌前磨牙,自釉牙骨质界处截冠后行完善的根管治疗,随机分为A、B、C 3组,每组10颗.对应每组按5mm(短于修复体牙冠的长度),7mm(等于修复体牙冠的长度),9mm(大于修复体牙冠的长度)长度的纤维桩修复,树脂核加金属冠修复外形.自凝塑料包埋后,固定于万能试验机上测试实验牙的抗折强度,记录读数并观察修复体折裂模式.结果 A组的修复体抗折强度低于B组与C组(P<0.05),而B组与C组修复体抗折强度的差异无统计学意义(P>0.05).结论 使用玻璃纤维桩修复缺损牙体时,桩的长度不应短于临床牙冠的长度.