Influence of liquid films on mercury vapor loss from dental amalgam.
OBJECTIVE
The aim of this study was to determine the effect of aqueous liquid films on Hg emission from of dental amalgam.


METHODS
Amalgam specimens (4 mm dia. x 4 mm long) made from ten alloys were uniformly abraded on wet ASTM 600 grit SiC paper, quickly dried and covered by liquid films of a thickness that approximated the thickness of saliva films on tooth surfaces in vivo. Distilled water and two formulations of artificial saliva were tested. After abrasion and film placement, the specimens were immediately inserted in a plastic tube which was then closed. After 30 min, the Hg vapor that had collected in the tube was measured using a Jerome 411Hg analyzer. Hg emission from abraded surfaces exposed to air was also measured and used for comparative purposes. The test results were compared using ANOVA and Tukey's contrast test (p=0.05).


RESULTS
Hg emission from abraded surfaces under liquid films was one to two orders of magnitude less than Hg emission from abraded surfaces exposed to air.


CONCLUSIONS
In vitro measurement of Hg vapor emission from abraded surfaces exposed to air should not be used to estimate directly the Hg vapor release from dental amalgam restorations in vivo.
Mahler
David B
DB
Department of Biomaterials and Biomechanics, Oregon Health Sciences University, Portland, OR, USA. mahlerd@ohsu.edu
Adey
Jerome D
JD
Simms
Lisa E
LE
Marek
Miroslav
M
D000393:Air Pollutants / Q000032:analysis; D000704:Analysis of Variance; D019540:Area Under Curve; D003723:Dental Amalgam / Q000737:chemistry*; D003741:Dental Deposits; D006801:Humans; D008452:Maximum Allowable Concentration; D008628:Mercury / Q000032:analysis*; D012044:Regression Analysis; D012463:Saliva / Q000502:physiology; D012464:Saliva, Artificial; D018709:Statistics, Nonparametric; D014835:Volatilization; D014867:Water
D000393:Air Pollutants; D012464:Saliva, Artificial; D014867:Water; D003723:Dental Amalgam; D008628:Mercury