Previous in vitro studies have suggested that simvastatin can be used as a direct pulp capping material due to its ability to induce odontoblastic differentiation and angiogenesis. The aim of this animal study was to evaluate the pulpal response to mineral trioxide aggregate (MTA) and four concentrations of simvastatin/MTA in combination. The study was conducted in two stages using four different simvastatin concentrations and MTA as a capping material for rat maxillary molars. The grades of inflammation and continuity of dentin formation were evaluated in hematoxylin and eosin (HE)-stained samples. Dentin thickness was determined by histomorphometric analysis, and the data were subjected to statistical analysis. On day 3, mild inflammation was observed in all groups. On day 7, the simvastatin groups showed a slightly higher rate of chronic inflammation. Inflammation was not present on day 30. Discontinuous dentin was present in all methylcellulose (control) samples. Continuous dentin was formed in all of the samples treated with 1.5% simvastatin. The greatest dentin thickness was observed after treatment with 1.5% simvastatin and MTA, followed by 0.5% simvastatin. Statistical analysis demonstrated no significant differences in dentin thickness and continuity between MTA and simvastatin at 0.5% and 1.5% (P > 0.05).
Keywords: MTA; direct pulp capping; histomorphometry; rat molars; simvastatin.