Cytotoxic effects of dental desensitizers on human gingival fibroblasts

The purpose of this study was to evaluate the effects of three different desensitizers on the cell viability and morphology of human gingival fibroblasts (HGF). Human gingival tissues were obtained from individuals who have clinically, healthy periodontium. HGF were grown at 37 degrees C in humidified atmosphere of 5% CO2 in Dulbecco's modified eagle's medium, supplemented with glutamine, penicillin, streptomycin, and 10% fetal bovine serum. The cells were treated with different concentrations (0.1, 0.3, and 0.5 microL/mL) of desensitizers (Gluma Desensitizer, Seal&Protect, and MicroPrime). After 24- and 48-h exposure to the desensitizer solutions, the viable cells were examined using a hemocytometer. To monitor HGF viability, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used and cell morphology was also observed at 48 h. Following exposure to concentrations of 0.1 microL/mL of test materials for 24 h, cell survival rates for Gluma Desensitizer (106%) and Micro Prime (62%) were not significantly different from the control, while it was significant for Seal&Protect (50%). Growing cells were significantly inhibited by all tested materials for 48 h (p < 0.05) in survival rates of 51, 47, and 31%, respectively. On the basis of the MTT assay, the cytotoxic effect of MicroPrime was more prominent, especially at high concentrations, than does Gluma Desensitizer and Seal&Protect. After exposure to Seal&Protect and MicroPrime, HGF became retracted, rounded in appearance and had loss of normal organization, leading to enlargement of intercellular space when compared with Gluma Desensitizer. As a conclusion, taking the limitations of an in vitro experiment into consideration, the cytotoxic effects were varied, depending on the chemical composition and exposure periods of the tested desensitizers.