Biomineralization Ability of Two Calcium Silicate-based Endodontic Materials

Objectives: The purpose of this study was to investigate the biomineralization ability of two biocompatible calcium silicate-based endodontic materials: BiodentineTM (BD, Septodont. France) and White ProRoot MTA (MTA, Dentsply Tulsa Dental, U.S.A.). Methods: Root canals of bovine incisors were instrumented using a #140 K file and irrigated with 17% ethylenediaminetetraacetic acid followed by 3% sodium hypochlorite for 1 minute each. These canals were immediately washed in distilled water, dried, and filled with either BD or MTA mixed according to the manufacturer's instruction. The filled specimens were stored at a relative humidity of 100% for 4 hours, and then immersed individually in a plastic vial containing 20 ml of a Ca- and Mg-free phosphate-buffered saline solution (PBS, pH 7.2) for 1, 7, 30 and 90 days (n = 3, each). After given periods, the specimens were sectioned longitudinally into two symmetrical pieces and processed for morphological observation and chemical composition analysis of the dentin-material interfacial area with a wavelength-dispersive X-ray spectroscopy electron probe microanalyzer with image observation function (SEM-EPMA). Results: Both BD- and MTA-filled specimens showed a layer of high Ca concentration in the outermost layer of the dentin in contact with the materials. A narrower Si-concentrated layer was also detected. The width of the Ca- and Si-concentrated layer was larger in BD-filled specimens than MTA-filled specimens, and increased with the prolongation of the immersion period. Conclusion: Both BD and MTA caused the incorporation of Ca and Si in the adjacent root canal dentin in the presence of PBS. This may contribute to the biomineralization ability and sealing ability of this material.