3种桩核材料修复薄弱残根的抗疲劳强度比较

Resistance to cyclic fatigue of pulpless teeth with flared root canals restored with three kinds of post-and-cores

目的:探讨不同材质桩核修复对前牙薄弱残根抗疲劳强度的影响。方法:48颗离体上颌中切牙均分为无牙本质肩领和有牙本质肩领2个实验组,各实验组再分为3组,各8颗样本牙。每组分别用铸造金属桩核、预成碳纤维桩+复合树脂桩核、预成玻璃纤维桩+复合树脂桩核等3种桩核修复后再进行全冠修复。测定各样本牙疲劳强度,采用SPSS12.0软件包对实验结果进行双因素方差分析。结果:2个实验组中,用纤维桩核修复后薄弱残根的平均疲劳强度显著高于金属桩核修复组(P<0.05)。预备牙本质肩领可显著提高3种桩核材料修复牙的疲劳强度(P<0.05)。结论:纤维桩核在提高前牙薄弱牙根抗疲劳强度方面优于铸造金属桩核。保留牙本质肩领,对提高牙根的抗疲劳强度具有重要意义。

PURPOSE： To observe the resistance to cyclic fatigue of maxillary incisors with flared canals restored with three post-and-core materials. METHODS： Standard cylindrical samples with flared canals were made of 48 human maxillary central incisors and were assigned randomly to two groups （without ferrule and 2mm ferrule）. Each main group was then divided into 3 sub-groups of 8 specimens and restored with cast metal post-core-crown,carbon fiber＋resin composite post-core-crown ,and glass fiber＋resin composite post-core-crown, respectively. Each group was subjected to a cyclic fatigue test, and the numbers of load cycles that bad tooth fracture were measured with cyclic fatigue testing machine. All data were analyzed statistically for two-way ANOVA with SPSS 12.0 software package. RESULTS： Fiber＋ resin composite post-core-crown showed significantly higher fatigue strength than east metal post-core-crown in the two groups （P〈0.05）. Preparing dentin ferrules increased significantly fatigue resistance （P〈0.05）. CONCLUSION： Fiber post-and-core system may get a long fatigue life in restoring pulpless teeth.Dentin ferrule preparation is necessary to enhance resistance to cyclic fatigue.