SF-ICP-MS Analysis of Palladium in Fluids of Patients Sensitized to Metal-Based Dental Restorations

Abstract

Palladium (Pd) belongs to the platinum group elements and its use has more than doubled in the past ten years. Encouraged by positive patch test results in some patients suffering from oral syndromes, Pd was included in the routine patch testing for contact dermatitis. In the present study, differences in the trend of sensitization to Pd in a contact dermatitis clinic population between 1996 and 2006 were evaluated. Since many in vitro studies have confirmed the corrosion of dental alloys and indicated that metal components are released in the oral cavity, Pd content was examined in leaching solutions from dental prostheses and in samples of saliva, serum and urine of subjects with adverse reaction to dental prostheses. Measurements were performed by means of Sector Field Inductively Coupled Plasma-Mass Spectrometry (SF-ICP-MS). Results showed that the frequency of mono-reactions to Pd are increased from 1996 (0.11%) to 2006 (1.6%), suggesting that this metal is becoming a "new" potential allergen. The mean values of Pd levels detected in urine were higher than those found in saliva and in serum. All biological samples collected from patients showed significantly higher levels of Pd than controls (saliva, 255 ng/L vs 11; serum, 60 vs 15; urine, 580 vs 20). Moreover, after removal of the prostheses a consistent reduction of Pd content in fluids was observed.

Inductively Coupled Plasma Mass Spectrometry

“…Based on this assumption, Caimi et al determined palladium in urine, saliva and blood. 300 Three Pd isotopes, 105 Pd, 106 Pd and 108 Pd, were quantified by ICP-SFMS in medium resolution mode (R ¼ 3000). The authors present a long list of possible interfering ions for the various isotopes, whereby 108 Cd is of major concern for the determination of 108 Pd.…”

Assessment of exposures and potential risks to the US adult population from the leaching of elements from gold and ceramic dental restorations

“…1 Elements from gold (Au) alloy and ceramic restorations have been observed in saliva at least 6 months after placement, 2 and components of Au alloys continue to be observed in dental patients' blood for at least 15 years post placement. 3 A variety of other surveys of persons with Au alloy restorations [4][5][6][7][8][9][10] have also observed elevated levels of Au, Pd, Pt and other metals in saliva, blood and urine, often years after restoration placement. It is apparent, therefore, that chronic exposure to components of these dental materials does occur, although the relative contributions of leaching versus wear to long-term exposure is not evident from the published literature.…”