Introduction: Bisphosphonates have been therapeutically used for the management of lytic bone diseases. Their use has been increased nowadays and besides that associated adverse effects have been amplified. Jaw osteonecrosis induced by this drug is perhaps the most important complication because of the great morbidity and difficulty to deal with.

Aims: This study aimed to evaluate the effect of sodium alendronate on the viability and proliferation of osteoblasts (OSTEO 1) and fibroblasts (FMM1) in culture.

Methods: Cell viability and proliferation were determined with the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. The cells where submitted to different concentrations of sodium alendronate range from 10 ⁻² M to 10 ⁻⁸ M.

Results: After being subjected to tests with concentrations of sodic alendronate ranging from 10 ⁻⁸ M to 10 ⁻² M fibroblasts showed a significant decrease in cell viability at the concentration of 10 ⁻² M ( p < 0.01). Osteoblasts showed that the cell viability in the control group was significantly higher than all other groups, the group treated with alendronate at a concentration of 10 ⁻⁴ M had similar cell viability with all groups except the group of 10 ⁻² M concentration and the cell viability of other groups was similar between groups ( p < 0.01). The concentrations of alendronate greater than 10 ⁻⁵ M prevented the proliferation of osteoblasts.

Conclusions: Sodium alendronate were cytotoxic to osteoblast-símile cells and fibroblasts in culture due to its concentration. The fibroblasts were less sensitive to higher concentrations of alendronate than osteoblasts.

Conflict of interest: None declared.