In vitro comparison of chlorhexidine and povidone-iodine on the long-term proliferation and functional activity of human alveolar bone cells.

This work reports the behaviour of osteoblastic human alveolar bone cells (first subculture) in the presence of chlorhexidine (CHX) and povidone-iodine (PI). Short contact (2 min) of 24-h cultures with CHX, at 0.12 and 0.2%, and PI, at 5 and 10%, caused cell death within minutes; contact with 1% PI resulted in loss of the elongated characteristic cell shape. Cell adhesion was adversely affected at concentrations higher than 5 x 10(-5)% CHX or 0.05% PI. Long-term exposure to CHX at 10(-5) and 10(-4)% or PI at 10(-4)% had little effect on cell growth and caused an induction in the synthesis of alkaline phosphatase (ALP). Concentrations of CHX and PI similar and higher than, respectively, 5 x 10(-4)% or 0.05% caused dose-dependent deleterious effects. CHX affected mainly the cell growth, whereas the effects of PI were observed mostly in ALP production and matrix mineralization. Considering the levels of CHX and PI used routinely in the oral cavity, results suggest that CHX has a higher cytotoxicity profile than PI. This observation might have some clinical relevance regarding the potential utility of PI in the prevention of alveolar osteitis.