Biomaterial Database

Comparative electrochemical investigation of the effect of aging on corrosion of dental amalgam. 2007

Wala M Amin

Department of Conservative Dentistry and Prosthodontics, Faculty of Dentistry, University of Jordan, Amman, Jordan. wami@ju.edu.jo <wami@ju.edu.jo>

OBJECTIVE To investigate corrosion in dental amalgam and evaluate the effects of composition and long-term aging on the alloy's corrosion behavior. METHODS A sample of high-copper and low-copper formulations was employed. Corrosion tests were performed using a 3-electrode polarization cell. Anodic polarization curves were drawn, and the potential and the current density corresponding to the first anodic peak were registered. Scanning electron microscopy was performed, and the different metallurgical phases of the alloy's microstructure were examined and analyzed chemically using an energy-dispersive x-ray technique. The amalgams' corrosion behavior was evaluated at 1 week and after aging in a simulated oral environment for 6 months, 1 year, and 2 years. Data were analyzed using analysis of variance (ANOVA)Scheffe post hoc test at a .05 significance level. RESULTS The potential values recorded by the high-copper amalgam were higher (P <.05) than those scored by the low-copper alloy. This was attributed to the presence of a tin-mercury, g2, phase in larger quantities in the low-copper amalgam than in the high-copper alloy. For both formulations the potentials increased significantly (P <.05) by about 70 mV after 2 years. This was ascribed to the gradual elimination of the corrosion-susceptible g2 phase and formation of a tin-copper, h, phase, particularly in the high-copper amalgam. CONCLUSIONS High-copper amalgam exhibited better resistance to corrosion than the low-copper alloy. Aging in a simulated oral environment improved corrosion behavior for both high- and low-copper amalgams.

UI	MeSH Term	Description	Entries
D008628	Mercury	A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200.59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to MERCURY POISONING. Because of its toxicity, the clinical use of mercury and mercurials is diminishing.
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003343	Corrosion	The gradual destruction of a metal or alloy due to oxidation or action of a chemical agent. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Corrosions
D003723	Dental Amalgam	An alloy used in restorative dentistry that contains mercury, silver, tin, copper, and possibly zinc.	Amalgam, Dental,Amalgams, Dental,Dental Amalgams
D004572	Electrolysis	Destruction by passage of a galvanic electric current, as in disintegration of a chemical compound in solution.	Electrolyses
D004577	Electron Probe Microanalysis	Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.	Microscopy, Electron, X-Ray Microanalysis,Spectrometry, X-Ray Emission, Electron Microscopic,Spectrometry, X-Ray Emission, Electron Probe,X-Ray Emission Spectrometry, Electron Microscopic,X-Ray Emission Spectrometry, Electron Probe,X-Ray Microanalysis, Electron Microscopic,X-Ray Microanalysis, Electron Probe,Microanalysis, Electron Probe,Spectrometry, X Ray Emission, Electron Microscopic,Spectrometry, X Ray Emission, Electron Probe,X Ray Emission Spectrometry, Electron Microscopic,X Ray Emission Spectrometry, Electron Probe,X-Ray Microanalysis,Electron Probe Microanalyses,Microanalyses, Electron Probe,Microanalysis, X-Ray,Probe Microanalyses, Electron,Probe Microanalysis, Electron,X Ray Microanalysis,X Ray Microanalysis, Electron Microscopic,X Ray Microanalysis, Electron Probe
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D012834	Silver	An element with the atomic symbol Ag, atomic number 47, and atomic weight 107.87. It is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. Long-continued use of silver salts can lead to a form of poisoning known as ARGYRIA.
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor