Objective To explore the influence of different lengths and contents of glass-fiber post on the fracture resistance of teeth, and to investigate the optimal length and content of glass-fiber post used for restorative treatment. Meth-ods Forty-two intact single canal mandibular premolars were collected from orthodontic patients and were divided into three experimental groups (A, B and C). All the teeth were endodontically treated after cut off the crowns from the 2 mm above cemento-enamel junction. The post lengths were10 mm in A group, 8 mm in B group, and 6 mm in C group.There were two subgroups for each experimental group (A1, A2, B1, B2, C1, C2 ), 7 teeth for each subgroup.The 42%glass fiber post was used in A1, B1 and C1 groups. The 75%glass fiber post was used in A2, B2 and C2 groups. All of groups were restored with resin cores and metal crowns. The fracture resistance was measured with universal testing machine and recorded the root frac-ture pressure data and the mode of all the teeth. Results The fracture resistance was significantly higher in group A than that of group B and group C (P<0.05), and the fracture resistance was significantly higher in group B than that of group C (P<0.05). The fracture resistance was significantly higher for 75%glass fiber post than that of 42%glass fiber post (P<0.05). Conclusion Within a certain range, the longer the length of glass fiber post, the greater the tooth fracture resistance. The fracture resistance of fiber content is better for 75%glass fiber post than that of 42%glass fiber post.%目的：研究玻璃纤维桩长度和纤维含量对牙齿抗折强度的影响，探索进行牙体缺损修复所适宜的玻璃纤维桩长度和纤维含量。方法选择42颗因正畸拔除完整的下颌前磨牙，随机分为A、B、C3个实验组，每组14颗牙。自釉牙骨质界上2 mm截冠后行完善的根管治疗，进行桩道预备，桩道深度分别为A组10 mm、B组8 mm、C组6 mm。每个实验组再各分成2个亚组，每组7颗牙。A1、B1、C1组应用纤维含量42%玻璃纤维桩，A2、B2、C2组应用纤维含量75%玻璃纤维桩，进行桩粘接、树脂核塑型及金属冠修复。将所有实验标本制成试件，置于万能材料实验机上进行抗折裂强度测试，记录牙根折断时的瞬间压力值以及试件折断的模式。结果玻璃纤维桩修复后的牙体抗折强度A组高于B组及C组，B组高于C组（均P<0.05）；纤维含量75%玻璃纤维桩高于纤维含量42%玻璃纤维桩（P<0.05）。结论用玻璃纤维桩修复缺损牙体时，在一定范围内，桩的长度越长，牙体抗折强度越大。纤维含量75%玻璃纤维桩修复后牙体抗折强度大于纤维含量42%玻璃纤维桩。
展开▼
