Elemental analysis of crystal precipitate from gray and white MTA.

Crystal growth and elemental dissolution characteristics of gray Mineral Trioxide Aggregate (GMTA), white MTA (WMTA), and an experimental material, Dentalcrete, were compared. For part A, comparing amount and composition of surface crystal growth, twelve cylinders of each material were suspended in Phosphate Buffered Saline (PBS) solution without Ca. The crystals were analyzed by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Inductively Coupled Plasma--Atomic Emission Spectroscopy (ICP-AES). For part B, three cylinders of each material were suspended in distilled, deionized water. The water was analyzed by ICP-AES for Ca content at 24 h, 72 h, and 5, 7, 10, and 14 days. Data were analyzed using one-way ANOVA and Tukey test. Both MTA materials released more Ca initially, followed by a decline and then rise in elution. GMTA produced the most surface crystal, which may be clinically significant. The crystals on GMTA and WMTA were chemically and structurally similar to hydroxyapatite (HA).