Effect of 10% Carbamide Proxide on Mercury Release from Two Types of Dental Amalgam

Statement of problem: the chemical reactions occur at the amalgam surfacewhen exposed to bleaching agents. mercury ion is released from dental amalgamwhen bleached.purpose: the aim of this in vitro study was to investigate the effect of carbamideperoxide (cp) on the release of mercury ion from two types of sphericaldental amalgam.materials and method: two commercial brands of dental amalgam, cinaluxand gs-80, were selected. 18 amalgam discs of any brand were prepared insilicon moulds according to the manufacturer's instructions. after 60 minutes, thediscs were removed and individually immersed in artificial saliva (as) for 24 hat 37 0c. then, the discs of any amalgam were divided into two equal test group(a) and control group (b). each specimen in the test group was treated in eighthourcycles with 10% cp. the specimens of the control group was treated insimilar cycles with as. all of the solutions were taken for hg ion release determination,using cold-vapor atomic absorption mercury analyzer system. the datawere analyzed using general linear model followed by repeated measuresanova.results: the results indicated that the bleaching agent significantly caused moremercury ion to be released into the solutions ( p <0.05) but artificial saliva didnot show this effect. the release rate of mercury from the cinalux during the twoweeks of treatment period with 10% cp showed an increase from 11.63 ìg/lit inthe first day to 228.85 ì g/lit in the last day. the release rate from gs-80 showeda decrease from 130.96 ìg/lit in the first day to 80.68 ì g/lit in the last day.conclusion: treatment with %10 carbamide peroxide increased mercury releasefrom dental amalgam in comparison with the artificial saliva. the release of hgfrom 2 brands of dental amalgam was in a safe range.