玻璃纤维桩对不同程度牙体缺损抗折能力的影响

Influence of glass fibre posts on the fracture resistance of teeth with different defect in vitro

目的研究玻璃纤维桩核冠和树脂核冠修复下颌第一前磨牙不同数量缺损壁后的抗折能力。方法根据不同的缺损壁数目及修复方法,随机分为6组。A1组:一壁缺损+玻璃纤维桩核冠修复;A2组:一壁缺损+树脂核冠修复;B1组:二壁缺损+玻璃纤维桩核冠修复;B2组:二壁缺损+树脂核冠修复;C1组:三壁缺损+玻璃纤维桩核冠修复;C2组:三壁缺损+树脂核冠修复。使用力学实验机对各组离体牙进行加载直至破坏,记录最大负载值及破坏模式。结果采用两独立样本的t检验进行统计。结果一壁缺损时,纤维桩核冠修复组(A1组)与树脂核冠修复组(A2组)之间的最大负载力差异无统计学意义(tA=1.830,PA=0.10)。二壁及三壁缺损时,玻璃纤维桩核冠修复组(B1组、C1组)分别与树脂核冠修复组(B2组、C2组)之间的最大负载力差异有统计学意义(tB=4.741,PB=0.001;tC=3.491,PC=0.005)。不可修复性折裂主要发生在A1、A2、B2组。结论玻璃纤维桩核冠与树脂核冠修复一壁缺损牙体后抗折能力没有显著性差异,因此临床上对一壁缺损牙体可以只作树脂核冠进行修复。当牙体有二壁或者三壁缺损时,玻璃纤维桩核冠修复后牙体的抗折能力优于树脂核冠修复后牙体的抗折能力。

Objective To analyze the influence of glass fibre post restoration on premolars fracture resistance with different numbers of coronal dentin walls defect. Methods According to different numbers of coronal dentin walls defect and restoration methods, forty-eight mandibular first premolars were randomly divided into six groups. Group A1： one-wall defect with glass fibre post-composite resin core restoration; Group A2： one-wall defect with composite resin core restoration;Group B1： two-wall defect with glass fibre post-composite resin core restoration; Group B2： two-wall defect with composite resin core restoration; Group C1： three-wall defect with glass fibre post-composite resin core restoration; Group C2： three-wall defect with composite resin core restoration. Every sample was loaded till failure by mechanical testing machine. The maximum loading value and failure mode were recorded. Two independent samples t test was used in statistical analysis. Results There is no statistical significance in the maximum loading capacity between Group A1 and Group A2 （P 〉 0.05）. Statistical significance was found in the maximum loading capacity between Group B1 and B2, as well as Group C1 and C2 （P﹤0.05）. Irreparable fracture mainly occurs in Group A1, A2 and B2. Conclusions There is no effect of glass fibre post-composite core restored on the fracture resistance of teeth with one-wall defect （tA=1.830, PA=0.10）. When the number of coronal dentin wall defect is two or three, glass fibre post-composite core restoration is better than composite resin core restoration on the fracture resistance of teeth （tB=4.741,PB=0.001;tC=3.491,PC=0.005）.