Effect of Pd and In on Mercury Evaporation from Amalgams

• Published in: Dental Materials Journal Vol. 16; no. 2; pp. 191 - 199,226
• Main Authors: OKABE, Toru, OHMOTO, Kazuhiro, NAKAJIMA, Hiroshi, WOLDU, Margaret, FERRACANE, Jack L.
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society for Dental Materials and Devices 01.12.1997
• Subjects: Amalgam; Calorimetry, Differential Scanning; Dental Amalgam - analysis; Dental Amalgam - chemistry; Dentistry; Dose-Response Relationship, Drug; Indium - analysis; Indium - chemistry; Mercury; Mercury - analysis; Mercury - chemistry; Microscopy, Electron, Scanning; Palladium; Palladium - analysis; Palladium - chemistry; Powders; Time Factors; Volatilization; X-Ray Diffraction
• ISSN: 0287-4547; 1881-1361
• DOI: 10.4012/dmj.16.191

The amount of Hg vapor released from “synthesized” γ1 with 1% (wt) Pd was reported to be less than 30% of that from γ1 with no Pd. This study tested the hypothesis that Hg evaporation from Pd-containing amalgams decreases with Pd concentration and that In also reduces Hg vapor. Specimens (4mm dia, 8mm long) were prepared by triturating Ag-Sn(25%)-Cu(12%) alloy powder containing 0.5-9.0% Pd with pure Hg and by triturating 3% Pd alloy powder with Hg containing 1-5% In (all residual Hg≅62%). The total amount (ng/mm2) of Hg vapor released at 37°C from freshly prepared amalgams was measured. Pd (3-9%) in the powder significantly (p<0.05) decreased Hg vapor release from amalgams during setting. Use of In-containing Hg also reduced Hg vapor release (5% In, p<0.05). The reduction in the Hg vapor pressure by adding Pd and the rapid oxide film formation on the In-containing amalgam appear to work together to reduce Hg vaporization from these amalgams.