Morphological cell changes due to chemical toxicity of a dental material: an electron microscopic study on human periodontal ligament fibroblasts and L929 cells.

New endodontic materials with polymer bases may be more difficult to evaluate in cell cultures in vitro than conventional zinc oxide-eugenol cements. In order to study the morphological changes taking place in cells exposed to such materials, L929 cells and human periodontal fibroblasts were observed using scanning electron microscopic and transmission electron microscopic techniques. The morphological changes of the cells were correlated to the quantitative results observed simultaneously in cytotoxicity studies using the radiochromium release method. Results showed there was a relationship between the chromium release and the degree of individual cell damage. The periodontal ligament fibroblasts were more resistant to this kind of chemical injury than the L929 cells. Consequently, it may be proper to use periodontally derived cells for the study of cytotoxic mechanisms of polymer endodontic filling materials.