J Endod. 2006 May;32(5):425-8. Epub 2006 Feb 17.
Elemental Analysis of Crystal Precipitate from Gray and White MTA T.B. BOZEMAN1, R. LEMON2, P.D. ELEAZER1, and X. XU3, 1University of Alabama, Birmingham, USA, 2Louisiana State Unviversity Health Science Center School of Dentistry, New Orleans, USA, 3Louisiana State University Health Sciences Center School of Dentistry, Center of Excellence of Craniofacial and Oral Biology, New Orleans, USA
Abstract 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). Objectives: To compare the elemental dissolution characteristics and crystal growth characteristics of gray Mineral Trioxide Aggregate (MTA), white MTA, and an experimental material called Dentalcrete. Methods: Part A: Three circular samples (12mm diameter, 4mm thick) of each of three materials (9 samples total) were suspended in 40ml deionized water. The water samples were collected and changed for six time intervals: 1,3,5,7, 10, and 14 days. The collected water samples were analyzed by ICP-AES for Ca and other elements. Part B: Twelve circular samples (12mm diameter, 4mm thick) of each of the three materials (36 samples total) were suspended in 40ml Phosphate Buffered Saline (PBS) solution without calcium for 40 days to study the crystal growth characteristics of the materials. The crystals were analyzed by SEM, XRD and ICP-AES. Data from part A and B were analyzed using one-way ANOVA and Tukey test. Results: For each time interval, variations were noted in the amount of Ca released between the three materials and between each sample within a material group. Generally, both MTA materials released more Ca initially, followed by a significant decline and then rise in elution. White MTA released statistically the same amount (47Âą8mg/L) of Ca as gray MTA (55Âą12mg/L) in 14 days (p>0.05). Dentalcrete released less Ca than both MTA materials, (p<0.05). The crystals grown on the surface of gray and white MTA were determined to be chemically and structurally similar to hydroxyapatite (HA), with gray MTA producing the greatest amount of crystal (0.82g). Dentalcrete produced no detectable crystal growth. Conclusion: White MTA and gray MTA release statistically the same amount of Ca, whereas both MTA
materials released a statistically significant greater amount of Ca than Dentalcrete. Gray and white MTA both show growth of HA crystal in PBS. Supported by Dentsply/Tulsa Dental. PMID: 16631841 [PubMed - indexed for MEDLINE]