不同直径预成氧化锆桩和纤维桩修复的抗折性比较

目的观察不同直径预成氧化锆桩和纤维桩与核树脂桩核冠修复上颌中切牙的抗折力。方法 24颗完整上中切牙根管充填后随机分为4组,分别采用直径1.5mm、1.35mm预成氧化锆桩和直径1.5mm、1.375mm预成纤维桩与核树脂加Ni-Cr合金铸造冠修复。对所有样本进行抗折实验,并对其断裂模式进行观察和分析。结果直径1.5mm、1.35mm预成氧化锆桩组抗折力为508.5±143.3N和434.9±141.7N,大于直径1.5mm、1.375mm的预成纤维桩组抗折力(292.2±54.5N,238.5±79.1N),差异有统计学意义(P<0.05)。预成氧化锆桩组样本的损坏模式为桩的断裂或合并根颈部的损伤,根颈部的损伤中50%为破坏性牙折;预成纤维桩组样本的损坏模式为桩的弯曲,根颈部的损伤中83.3%为可修复性牙折。结论预成氧化锆桩与核树脂桩核冠修复上颌中切牙可承受较高的载荷,预成纤维桩对预防破坏性根折有利。

Fracture resistance of maxillary incisors restored with different diameters of prefabricated Zirconia and fiber post with core resin material

Objective To investigate the fracture resistance of maxillary incisors restored with different diameters of prefabricated Zirconia and fiber post with core resin material. Methods Twenty-four isolated maxillary central incisors which had received root cannl treatment were divided into 4 groups, which were then restored with 1.5mm, 1.35mm diameters of Zirix post and 1.5mm, 1. 375mm diameters of fiber post, respectively. The fracture resistance of the samples was tested by universal test machine and the fracture modes were observed. Results The fracture resistance of 1.5ram and 1.35mm diameters of Zirix post was 508. 5 ＋ 143.3N and 434. 9±141.7N,and of 1.5mm,1. 375mm diameters of fiber post was 292. 2 ±54. 5N and 238. 5 ±79. IN. There was a significant difference in resistance between prefabrieated Zirconia post and the fiber post （ P 〈 0. 05 ）. 50% of the prefabricated Zirconia post samples fractured at the root cervical portion and 83. 3% of the fiber post samples fractured could be retreated. Conclusion Prefabricated Zireonia post could bear higher fracture load.