RESUMO
AIM: To compare the histological pulp reaction to various water/powder ratios of white mineral trioxide aggregate (MTA) as a pulp-capping material in healthy human teeth. METHODOLOGY: Twenty-nine disease-free maxillary and mandibular third molar teeth, scheduled for extraction, were exposed mechanically and then capped with 0.28, 0.33 and 0.40 water/powder ratios of white MTA (ProRoot; Dentsply Maillefer, Ballaigues, Switzerland) and restored with glass ionomer. After 30 days, the teeth were extracted, resected apically and immersed in 10% formalin. For histological processing, the teeth were sectioned buccolingually in 5-µm-thick slices, stained with Haematoxylin and Eosin and evaluated by a light microscope. Samples were evaluated for intensity and type of inflammation, presence of necrosis, as well as continuity, morphology and thickness of calcified bridges. The data were analysed by Kruskal-Wallis and Mann-Whitney tests. RESULTS: There were no significant differences in the diameter, morphology and continuity of the calcified bridges, intensity and type of inflammation or presence of necrosis (P > 0.05) in the pulps covered by MTA with various water/powder ratios. Two teeth failed to display a calcified bridge, and one had a pulp necrosis. CONCLUSION: Water-to-powder ratios of MTA had no significant influence on the histological outcome of direct pulp capping on healthy pulps.
