A histological study of pulp reaction to various water/powder ratios of white mineral trioxide aggregate as pulp-capping material in human teeth: a double-blinded, randomized controlled trial

Shahravan A, Jalali SP, Torabi M, Haghdoost AA, Gorjestani H. A histological study of pulp reaction to various water/powder ratios of white mineral trioxide aggregate as pulp-capping material in human teeth: a double-blinded, randomized controlled trial. International Endodontic Journal, 44, 1029-1033, 2011. 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 (Pro Root; 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-mu m-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.