Epithelial-like cells in culture derived from human gingiva: response to nickel

To obtain gingival cell cultures, human gingival tissue was minced and/or subjected to trypsin treatment with or without prior separation into epithelial and connective tissue portions. The tissues were then incubated in Eagle/Earle's MEM with 10% fetal calf serum in a humidified atmosphere of 5% CO2 in air. Fibroblast-like cell cultures were regularly obtained, and one culture showed epithelial-like cell islets that could be transferred and kept in continuous culture. These epithelial-like cells exhibited bone resorption stimulating activity as seen in gingival tissue and retained their growth pattern after prolonged storage. They were able to grow at serum concentrations down to 2.5% and with equal doubling time (about 17h) in rich or minimum essential media. Exposure to nickel gave toxic effects on the growth at concentrations down to 2.5 microgram/ml of nickel. In spite of the affinity of nickel to certain serum components, the serum concentration did not appear to be of specific importance to protect or aggravate the toxicity. It is felt that these cells may be of value for research on cytotoxicity of dental materials.