In vitro cytotoxicity of periodontally diseased root surfaces

The purpose of this experiment was to develop a model system for controlled in vitro testing of root surface toxicity. Human gingival fibroblasts were placed into a depression created in the root surfaces of ten heat sterilized periodontally involved teeth, one half of which were root planed to remove all irritants. The teeth and fibroblasts were incubated in culture medium for 5 days, after which the cells were fixed and stained. Each tooth was examined for migration of cells onto the root planed and non-root planed areas of the tooth, and for evidence of any cytotoxic reaction. No difference in pattern of cell growth, cell migration, or cytotoxic reaction was discernible between root planed and non-root planed areas. Normal fibroblasts could be detected on the surfaces of dentin, calculus, periodontally involved cementum, and enamel. It appears that heat-sterilized periodontally-involved root surfaces, as well as calculus and calculus-laden enamel, were not toxic to human gingival fibroblasts in cell culture.