耐氟变形链球菌对树脂-牙本质粘接强度的影响

Effect of fluoride-resistant strains of Streptococcus mutans on the bonding strength of dental resin composite

目的:探讨耐氟变形链球菌对树脂牙本质粘接强度的影响。方法:诱导培养耐氟变形链球菌UA159-FR及其亲代菌株UA159,选用复合树脂Z350和自酸蚀粘接剂Single bond Universal,制备牙本质-树脂复合体试件。将试件分为4组,分别浸入UA159-FR菌液、UA159菌液、BHI培养基、PBS中孵育14 d,每48 h换液1次,之后进行推出试验,检测试件粘接强度的变化。扫描电镜下观察4组粘接断面的情况。采用SPSS18.0软件包对数据进行统计学分析。结果:在UA159-FR和UA159侵袭下,牙本质-复合树脂粘接强度显著降低,组间无显著差异。粘接界面多为混合破坏,扫描电镜下可见大量的树脂突及部分粘接面破坏。结论:耐氟变形链球菌可破坏复合树脂粘接界面,引起粘接强度下降,破坏程度在短期内与亲代菌株无显著差异。

PURPOSE：The aim of this study was to determine the influence of fluoride-resistant strains of S.mutans on the bonding strength of dental resin composite.METHODS：Standardized specimens of resin composite（Z350）,and selfetch adhesives（Single bond Universal,3 M） were incubated with S.mutans UA159,fluoride-resistant strains of S.mutans UA159（UA159-FR） or uninoculated culture medium（Control） or PBS for up to 14 days.Resin-dentin bonded disks were subjected to push-out test.Fractured surface analysis of the specimens was performed by scanning electron microscopy（SEM）.SPSS18.0 software package was used for statistical analysis.RESULTS：UA159-FR and UA159 were shown to decrease the bond strengths in levels comparable with those found in the control groups（P 〈0.05）.SEM confirmed the increased degradation of all materials with UA159-FR and UA159,compared with control and PBS.CONCLUSIONS：The results suggest that resin-dentin interface can be compromised by oral bacteria that contribute to the progress of secondary caries.Fluoride-resistant strains of S.mutans and its parental strains both decrease bonding strengths in a short time,but no significant difference in the extent of damage.