title: Morphological and chemical analysis of different precipitates on mineral trioxide aggregate immersed in different fluids.
abstract: The purpose of this study was to analyze the ultrastructures and chemical compositions of precipitates formed on mineral trioxide aggregate (MTA; White ProRoot MTA) immersed in distilled water (DW) or phosphate buffered saline (PBS), based on the attribution that MTA's bioactivity and sealing ability are influenced by its interaction with the external fluid environment. After 1 and 14 days of immersion, precipitates formed on MTA disks were analyzed using wavelength-dispersive X-ray spectroscopy electron probe microanalyzer with image observation function (SEM-EPMA; EPMA1601, Shimadzu, Kyoto, Japan), and Fourier transform-infrared (FT-IR) spectroscopy. On DW specimens, cubic-like crystals containing Ca, O, and C (17, 66, and 17 at% respectively) were produced. State analysis of calcium k(β)spectrum also revealed calcium hydroxide. On PBS specimens, acicular-spherical and lath-like crystals with Ca/P molar ratios of 1.42 and 1.58 respectively were produced. In conclusion, the precipitates formed on DW specimens were identified as calcium carbonate and calcium hydroxide primarily, whereas the precipitates on PBS specimens were inferred to be amorphous calcium phosphate.
authors.affiliation: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, 5274 Gakkocho-dori, 2-ban-cho, Chuo-ku, Niigata 951-8514, Japan. han4378@yahoo.co.jp
authors.forename: Linlin
authors.initials: L
authors.lastname: Han
authors.forename: Takashi
authors.initials: T
authors.lastname: Okiji
authors.forename: Seigo
authors.initials: S
authors.lastname: Okawa
mesh_terms: D017607:Aluminum Compounds / Q000032:analysis / Q000737:chemistry*; D002021:Buffers; D002118:Calcium / Q000032:analysis; D002119:Calcium Carbonate / Q000032:analysis; D017610:Calcium Compounds / Q000032:analysis / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000032:analysis; D002130:Calcium Phosphates / Q000032:analysis; D002244:Carbon / Q000032:analysis; D011232:Chemical Precipitation; D003461:Crystallography; D004338:Drug Combinations; D004577:Electron Probe Microanalysis; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D010087:Oxides / Q000032:analysis / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012387:Root Canal Filling Materials / Q000032:analysis / Q000737:chemistry*; D017640:Silicates / Q000032:analysis / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D002021:Buffers; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D014867:Water; D010758:Phosphorus; D012965:Sodium Chloride; D002244:Carbon; C020243:calcium phosphate; D002119:Calcium Carbonate; D002126:Calcium Hydroxide; D010100:Oxygen; D002118:Calcium