ULTRAMICROANALYSIS OF DENTAL PLAQUE FILMS BY TOTAL-REFLECTION X-RAY-FLUORESCENCE

Microgram quantities of dental plaque were taken near amalgam fillings , gold crowns and intact teeth. Such extremely small samples can be an alysed by total reflection X-ray fluorescence (TXRF), a fairly new var iant of energy dispersive X-ray fluorescence (EDXRF). More than sixty samples were examined directly without chemical pretreatment. Fifteen elements of interest were detected simultaneously within a wide range of mass fraction and with detection limits of several mg/kg. A signifi cant correlation of the Hg-accumulation in plaque and the amalgam fill ings was established. Near these fillings Hg mass fractions can reach a level of 300 mg/kg. The results for other elements, e.g. Au, are les s significant.