A critical evaluation of the acute systemic toxicity test for dental alloys using histopathologic criteria.
The A.D.A. acute systemic test for type II, class 11 materials defines compliance on the basis of fewer than 50% mortality at 2 weeks. Histopathologic criteria were developed from pilot study data to evaluate the effects of these materials. In this double blind study, the frequency of histopathological changes in lung, liver, small intestine, and kidney were rated at 2 and 5 weeks, for six dental crown and bridge alloys ranging from 44% to 97% (Au, Pt, and Pd). Two positive 360 mg/kg and 1 g/kg of cadmium and two negative, a blank capsule and untreated control groups were used. There was significant difference (chi square test, X2 = 0.95) between the positive and negative controls at 2 and 5 weeks. The lung, liver, kidney showed the highest level of histopathological changes. Significant changes occurred in the four tissues for all alloys at two and five weeks. At five weeks, alloys with a lower noble metal content (44-62%, Au, Pd, and Pt) elicited significant chronic changes, while higher noble metal content (78-97%) showed healing and no significant difference from the negative controls. Applying histopathologic criteria and statistical parameters independent examiners can examine experimental animals and arrive at conclusive and reproducible results.
D000818:Animals; D001672:Biocompatible Materials; D003722:Dental Alloys / Q000633:toxicity*; D007421:Intestine, Small / Q000473:pathology*; D007668:Kidney / Q000473:pathology*; D008099:Liver / Q000473:pathology*; D008168:Lung / Q000473:pathology*; D051381:Rats; D014116:Toxicology / Q000379:methods
D001672:Biocompatible Materials; D003722:Dental Alloys