Effect of MDP agents on the bond strength of two self-adhesive resin cements to saliva-contaminated dentin substrates.

This study investigated the influence of 10-methacryloyloxydecyl dihydrogen phosphate (MDP) agents and repeated saliva contamination on the microtensile bond strength (µTBS) of two self-adhesive resin cements (SARCs) bonded to dentin. Forty-eight sound human teeth were randomly divided into eight experimental groups, based on three factors: the type of SARC, the presence or absence of an MDP agent, and the presence or absence of multiple saliva exposures. The control group for each SARC received neither MDP agent nor multiple saliva contaminations. For each group, five teeth were sectioned to obtain 30-44 beams, followed by µTBS testing, fracture mode analysis, and scanning electron microscopy. Data were analyzed using one-way and two-way analysis of variance, Scheffé's test, and Weibull statistics. Under uncontaminated conditions, the application of MDP agents was found to significantly enhance the bond strength of both SARCs. Saliva contamination significantly reduced µTBS, regardless of the cement used. However, when MDP agents were applied prior to bonding, µTBS values remained comparable to those of uncontaminated controls, even after multiple saliva exposures. These results support the use of MDP agents to maintain adhesive integrity in the presence of repeated salivary contaminations, offering greater reliability in adverse clinical environments.