[Usefulness of collagen gel matrix culture for biological evaluation of dental materials (in vitro)].

Cytotoxicity of zinc oxide-eugenol cement was investigated using collagen gel matrix culture. Diffusibility of the main components into the collagen gel was measured by either atomic absorption or ultraviolet spectroscopy. The agar overlay culture method was also carried out for comparison. Results from solution cultures containing diluted collagen were similar to those with diluted agar. Longer culture with either cement liquid, eugenol, or zinc chloride solution, resulted in more depressed cell growth. The lower the powder/liquid ratio for mixing, the higher the cytotoxicity for all the materials tested in gelled collagen. Also, cytotoxicity levels were always lower in cultures with collagen than in those with agar. Diffusibility of the materials into collagen gel was similar to that into agar, but the of diffused components in collagen gel was less. Thus, the usefulness of collagen gel matrix culture for biological evaluation of dental materials was equivalent to that of agar overlay culture. However, it is suggested that collagen as a tissue matrix might provide a favorable environment for cell culture, and hence allow biocompatibility testing of biomaterials under simulated conditions.