Some alloys used in restorative dentistry may evoke an allergic contact stomatitis in certain persons. In order to protect patients from material's with undesired reactions, and considering corrosion characteristics of different alloys used, it is useful to devise an adequate patch test battery to include the most relevant metals.
Dental alloys are composed of a combination of various metals. 12 different ions of frequent occurrence (Au3+ Pd2+, Zn2+, Mo6+, Sn2+, Ga3+, In3+, Co2+, Cr3+(6+), Ni2+, Fe2+(3+) and Si4+) were epicutaneously tested as the aqueous, solution 6f the respective salt. The concentrations are given in g/100 ml and also in m.mole/l. The 12 different metal ion solutions were patch tested on patients in 3 groups: one group with a positive history of contact stomatitis (30 patients, group 1), one group with a positive history of contact dermatitis (16 patients, group 2), and a control group (17 persons, croup 3). In contrast to the control group, a remarkable high percentage (11%) of positive skin reactions to Pd was found in groups 1 and 2. No allergic or irritant skin reactions were detected to Ga, Sn and Zn. No irritant reaction was observed at pH values as low as 1.5. In the case of SiCl4 (pH = 0.5). 41 % positive irritant reactions were evoked. In the group with a positive history of contact dermatitis (group 1). a positive reaction was found more often (69%) than in the group with a positive history of contact stomatitis (30%) (group 2). The difference between these groups was mainly caused by reactions to Ni and Pd.
It can be concluded in general that it is necessary that a reliable epicutaneous test batten, of metals is developed.