角度纤维桩核对牙根抗折能力影响的实验研究

目的:探讨不同角度可塑性纤维桩核对上颌中切牙牙根抗折能力的影响。方法:将60个离体上颌中切牙随机分为A、B两组。A组用可塑性EverStick纤维桩核修复,B组用Co-Cr合金桩核修复,两组均分别采用0°,10°,20°,30°,40°的改向修复方式,核外部制作标准厚度金属冠。将试件底座固定在电子万能试验机上,采用与牙根长轴成45°夹角的加载方式直至试件折裂。记录其折裂方式和折裂时最大负荷值。结果:A、B组之间最大负荷值有显著差异(P<0.05)。相同倾斜角度下最大负荷值A组>B组;A、B两组最大负荷值由0°～40°均逐渐递减,角度增大后纤维桩核组最大负荷值高于铸造金属桩核组。折裂方式:A组主要为牙颈部折裂,B组主要为牙根纵折。结论:金属桩核与可塑性EverStick纤维桩核修复上颌前牙唇向倾斜牙时,桩核舌向倾斜在30°之内均能满足临床需求,与金属桩核相比可塑性EverStick纤维桩核可以有效的减少牙根纵折。

Effect of EverStick Post-Core on root fracture resistance with different angles

AIM: To compare the effect of plasticity fiber post-core on root fracture resistance of maxillary central incisor with different angles.METHODS: Sixty maxillary central incisors were randomly divided into two groups,A and B.Group A was restored with plasticity EverStick fiber post-core,and Group B with Cobalt-Chromium alloy post-core.Then they were made into standard specimens with outside of metal crown with different angles formed by Post and long axis of Core(Such as: 0°,10°,20°,30°,40°).The specimens were fixed in electronic universal testing machine,and loaded from 45 ° angle(formed by the long axis of the root and specimen) until they fractured.The fracture mode and the maximum load values of fracture were recorded.RESULTS: The maximum load values between two groups were significantly different(P<0.05).The maximum load value was greater in group A than in group B at the same angle condition.The values decreased with the change of angles from 0°to 40°.The maximum value in fiber post-core group was higher than in cast metal post-core group.The fracture pattern of Group A was mainly neck fracture,but it was mainly vertical root fracture in Group B.CONCLUSION: Both plastic and metal post-core system can meet clinical needs when used to repair the anterior teeth inclined to the labial side,with an angle of no more than 30°,Compard with metal post-core,the plasticity of EverStick fiber post-core can prevent vertical root fracture much more effectively.