How proteolytic inhibitors interact with dentin on glass-fiber post luting over 6 months

Enzyme inhibitors minimize the degradation of unprotected collagen of dentin promoted by matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs). As the evidence of their effect on the root canal is limited, this study aimed to evaluate the role of EDTA, chlorhexidine and E-64 as antiproteolytic agents on the bond strength (BS) of glass-fiber posts in root canals.

Ninety-six bovine roots were distributed in groups for each time point (n = 8). Adper Scotchbond Multipurpose (MP)/ RelyX ARC system was used to lute the post according to the treatment: negative control (NC)- water, EDTA- 17% ethylenediaminetetraacetic acid, CHX- 2% digluconate chlorhexidine, E-64-5- 5μM E-64, E-64-10- 10μM E-64 and positive control (PC)- MP associated with activator/ catalyst. Then, slices were subjected to push-out test (0.5mm/min) after 24h/6 mons. Data were analyzed by three-way ANOVA/Tukey tests. Failure modes were analyzed (40×).

The factors treatment, time, root canal third and the interaction between treatment and time were statistically significant. At 24h, no negative interactions were observed among the root dentin, bonding system and post. At 6 mons, CHX improved the BS for middle and apical root thirds.

CHX was able to promote beneficial BS after 6 mons, which was not noted for any other tested enzyme inhibitors.