Dental gold alloys and contact allergy

Abstract

Contact allergy to gold as demonstrated by patch testing is very common among patients with eczematous disease and seems to be even more frequent among patients with complaints from the oral cavity. There is a positive correlation between gold allergy and the presence of dental gold. Gold allergy is often found in patients with non-specific stomatitides as well as in those with lichenoid reactions or with only subjective symptoms from the oral cavity. The therapeutic effect of substituting other dental materials for gold alloys is conspicuous in casuistic reports but less impressive in larger patient materials. The amount of dental gold is correlated qualitatively and quantitatively to the blood level of gold and the effects if any of circulating blood gold are unknown. There is clearly a need for prospective studies in the field and gold sodium thiosulfate is considered an important item in the dental series for patch testing.Key words: contact allergy; dental gold; gold alloy; lichenoid reaction, oral disease; stomatitis. C Blackwell Munksgaard, 2002. Accepted for publication 12 July 2002 DefinitionsThe term dental gold covers alloys containing gold as a component and included in the ISO standards (1, 2). Allergy to gold alloys implies contact allergy, i.e. the T-cell mediated, immunological state which is not expressed as a clinical reaction until a renewed contact with the hapten. A prerequisite for the induction as well as the elicitation of this allergy is dissolution and ionization of the metal followed by penetration of the hapten into the skin or mucous membrane. Dissolution of metallic gold is notoriously difficult but the process is facilitated by the presence of other metals in the alloy -the lower carat, the greater solubility of the gold (3) -but also by metals in the neighbourhood, e.g. amalgam through galvanism (4). Furthermore, dissolution and ionization are promoted by a high pH, an oxidative environment and the presence of amino acids, particularly sulfur-containing ones (3, 5). Diagnosis

Effect of Sintering on the Marginal and Internal Fit of CAD/CAM-fabricated Zirconia Frameworks

“…For the dual purpose of meeting patient expectations for good esthetic results and circumventing allergy concerns arising from contact with metallic frameworks [1][2][3][4][5][6][7][8] , all-ceramic restorations have become both a necessary alternative as well as a preferred choice. Against this background, all-ceramic fixed partial dentures (FPDs) using CAD/CAM-fabricated alumina and zirconia frameworks are now available and aplenty in clinics.…”

Oral Lichenoid Lesions and Allergy to Dental Materials

“…Other signifi cant corrosive products in amalgam include copper and tin, which may also be a cause of lichenoid mucosal changes 6,20 . Aside from amalgam, other metals, such as gold, palladium, nickel, chrome and cobalt may induce oral lichenoid mucositis [23][24][25] . In our set of patients, the greatest frequency of sensitization was to dental metals.…”

Gold und seine anorganischen Verbindungen [MAK Value Documentation in German language, 2006]

“…Daher ist die klinische Relevanz der in Fallberichten oder bei der Testung größerer Kollektive beschriebenen positiven Reaktionen zumeist unklar (siehe Tabelle 1). Dies gilt auch für Untersuchungen an größeren Kollektiven von Patienten mit Verdacht auf Unverträglichkeit von Zahn(ersatz)materialien (Alanko et al 1996;Möller 2002;Räsänen et al 1996), obwohl in mehreren Untersuchungen eine Korrelation der Häufigkeit für Gold-haltige Zahnrestaurationen und für eine positive Reaktion auf Goldverbindungen beobachtet wurde Schaffran et al 1999;Vamnes et al 2000). Über eine beruflich bedingte Sensibilisierung gegen Gold oder Goldverbindungen wurde nur selten berichtet.…”