Effect of different synthetic matrix metalloproteinase inhibitors on composite-dentin microtensile bond strength durability

Despite patient’s demand increased for tooth color restorations, the stable bond between dentin and composite is a challenge in dentistry. Dentin protease activation is responsible for dentin-resin bond failure. The aim of this study was to determine the best pretreatment agent to inhibit matrix metalloproteinase and increase resin-dentin bond durability. After collecting 24 intact third molars, the dentin surfaces were exposed immediately under DEJ. After acid etching of dentin rewetting was done with CHX 2%, EDC 0.3 M for 60 and water (control group). Then the adhesive (Single bond, 3M ESPE, USA) and composite (Filtek Z250 XT, 3M ESPE, USA) were applied. 48 sectioned dentinal specimens were prepared. The specimens were divided into 3 groups. Each group was divided into 2 sub groups (n=8). In half of each group, the micro tensile bond strength test was done immediately and another part half 6 months. Then, the specimens were evaluated by stereomicroscope and SEM. Statistical analysis was performed using SPSS23 software, two-way ANOVA and multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level. There were not significant differences between immediate micro tensile bond strength of CHX, EDC and control groups (P=0.97). However, there was significant differences between CHX, EDC compared with the control group (P≤0.0001). Comparison between the immediate and 6-month bond strengths in each group, only in EDC group, there was no significant after 6 months’ difference (P=0.64). EDC and CHX t did not have any effect on the immediate microtensile bond strength. After 6 months, EDC prevented bond strength deterioration, but the bond strength was decreased after CHX usage.