Abstract
This study was undertaken to evaluate the comparative reaction of oral mucous membrances to topical exposure to selected liquid dental materials. Elven adult mongrel dogs and five different liquid dental materials (50% citric acid, mercury, 50% phosphoric acid, eugenol and methyl methacrylate) were selected for this study. Each material was applied bilaterally to a specific area of the ventral surface of the tongue for 5 min. Sites were examined at 30 min and visual observations recorded. Animals were sacrificed 24 hr after application. hematoxylin and eosin stained microsections were examined without knowledge of the material used. Citric acid and phosphoric acid were associated with the most severe response, characterized clinically by surface necrosis and histologically by a dense, diffuse, neutrophilic infiltrate. Eugenol was associated with erythema, and in some cases, ulcers, with a moderate diffuse inflammatory infiltrate, histologically. Methyl methacrylate resulted in immediate surface dehydration followed by mild erythema with mild local inflammatory infiltration. Mercury produced no observable clinical or microscopic tissue response. This is a simple method for evaluating acute mucous membrane toxicity which may be used for screening liquid dental materials.