Hydroxyapatite-coated titanium alloy test strips were treated with chlorhexidine gluconate, stannous fluoride, citric acid, tetracycline HCl, polymyxin B, hydrogen peroxide, and a plastic Cavitron tip: untreated sterile strips served as controls. The strips were incubated with cultured human gingival and periodontal ligament fibroblasts. Image analysis of three photomicrographs of each test strip (original magnification ×350) indicated that the tetracycline HCl treatment resulted in significantly greater cellular surface area coverage compared with the other treatments. Citric acid and the plastic Cavitron tip also stimulated cell attachment, although the results from the Cavitron tip were not significantly different from citric acid or the other treatment groups. The remainder of the modalities and the untreated cellular controls experienced similar cellular coverage. (Implant Dent 1992;1:189-191)