Influence of matrix metalloproteinase inhibitors on resin-dentin bond strength and hybrid-layer characteristics of caries-affected dentin using a universal adhesive system.

BACKGROUND

Matrix metalloproteinase-mediated collagen degradation compromises the durability of resin-dentin bonds, particularly in caries-affected dentin. Natural matrix metalloproteinase (MMP) inhibitors have gained attention as biocompatible alternatives to conventional synthetic agents for improving adhesive stability.

OBJECTIVES

To evaluate the effects of natural and synthetic MMP inhibitors on microtensile bond strength and failure patterns in caries-affected dentin bonded with a universal adhesive using etch-and-rinse and self-etch modes.

MATERIALS AND

METHODS

A total of 240 extracted human permanent molars with artificially induced caries-affected dentin were allocated to 16 subgroups according to pretreatment agent and bonding mode. The pretreatment agents included grape seed extract, green tea extract, riboflavin, cranberry extract, chlorhexidine, doxycycline, sodium fluoride, and no inhibitor. A universal adhesive and nanohybrid composite resin were applied according to the assigned etch-and-rinse or self-etch protocol. Microtensile bond strength was measured using a universal testing machine. Data were analyzed using one-way analysis of variance, chi-square test, and Pearson correlation coefficient at a significance level of 0.05.

RESULTS

Etch-and-rinse bonding produced significantly greater bond strength than self-etch bonding. Grape seed extract and green tea extract showed the highest bond-strength values, followed by riboflavin and cranberry extract. Chlorhexidine, doxycycline, and sodium fluoride showed limited improvement. Adhesive failure predominated the association with bond strength.

CONCLUSION

Etch-and-rinse application of a universal adhesive combined with natural matrix metalloproteinase inhibitors, especially grape seed and green tea extracts, enhanced resin-dentin bond strength in caries-affected dentin.