Bioactivity of calcium aluminate endodontic cement.

INTRODUCTION: Calcium aluminate endodontic cement (CAEC) developed for use in root canal therapy has been produced with additives that improve handling properties and provide higher mechanical strength than mineral trioxide aggregate (MTA) according to prior studies. The aim of this study was to evaluate the bioactivity of CAEC containing accelerating additives (A-CAEC) in comparison with MTA, both in contact with simulated body fluid (SBF) solutions. METHODS: pH measurements were taken for set cement samples immersed in water or SBF solutions prepared according to the Kokubo and Rigo techniques. The surface of these materials kept in contact with SBF solutions were also evaluated by means of scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction. RESULTS: Because of the calcium hydroxide dissociation, MTA cement is able to release more Ca(2+) ions and results in a higher pH increase compared with A-CAEC. This behavior enhances the supersaturation of Kokubo solution, resulting in the precipitation of calcium phosphate phases on the MTA surface. On the other hand, for MTA in Rigo SBF solution, the pH value attained was higher than for the Kokubo SBF solution as a result of the Mg(2+) ion precipitation, which inhibited the calcium phosphate phase formation. For A-CAEC, the optimal precipitation conditions of calcium phosphate phases are achieved in Rigo SBF solution. CONCLUSIONS: MTA and A-CAEC present bioactivity in contact with SBF solution although the composition of this solution defines the type of phase precipitated.