Captopril inhibits matrix metalloproteinase activity and improves dentin bonding durability.

Abstract

We investigated the inhibitory effects of captopril on matrix metalloproteinases (MMPs) and its effect as a primer on dentin bonding durability. One hundred fifty human third molars were selected. Flat surfaces of the middle dentin were exposed, etched 15s, and followed by pretreatment with a primer for 60s, including distilled water (control, the negative control primer), 2% chlorhexidine digluconate (CHD,the positive control primer), and captopril solution. Inhibitory effects of primers on MMPs were evaluated by hydroxyproline and gelatinase activity tests. All primers were applied on dentin followed by bonding. Some of the samples were sliced into slabs, placed in a fluorescent solution containing gelatin, and incubated for in situ zymography. Some were cut into sticks, and after aging for 1day, 12months, or 24months, microtensile bonding strength was tested. Some were cut into slabs, aged for 1day, 12months, or 24months, and taken out for nanoleakage tests to reveal interface defects. Hydroxyproline and gelatinase activity analyses showed that captopril exerted better inhibitory effects on MMPs, relative to 2% CHD (p < 0.05). A 0.2% captopril aqueous solution (0.2% CapW) was chosen to apply to the dentin. In situ zymography showed that inhibitory effects of captopril on gelatinase were significantly higher compared to 2% CHD (p < 0.01). Microtensile strength revealed that the bonding effects of the 0.2% CapW group lasted longer, compared to the control and 2% CHD groups (p < 0.05). Interface defects, detected by nanoleakage, were significantly reduced in the 0.2% CapW group, compared to the control and 2% CHD groups (p < 0.05). Captopril inhibits dentin MMP activities and effectively improves dentin bonding durability. Captopril is a promising dentin bonding primer for improving bonding durability.