Background and Aim: It has been demonstrated that smoking has various detrimental effects on periodontal health. These toxic effects are mediated in large part by nicotine. The purpose of this study is to examine the effect of nicotine on various functions of the periodontal ligament fibroblasts (PDLF), such as cell proliferation, viability as well as metabolic activity after exposure to nicotine.

Materials and Methods: PDLFs were obtained from healthy teeth extracted for orthodontic reasons. PDLF cells were exposed to increasing amounts of nicotine up to 500ng/ml for a duration of 48 and 72 hours. Cell viability was assessed using Crystal Violet dye and then analyzed by microscope imaging. Cell proliferation and metabolic activity was measured using WST-1 assay.

Results: A dose-dependent toxic effect of nicotine was observed, especially with 500ng/ml nicotine exposure. Cell morphology alterations and vacuole formation were observed at 500ng/ml nicotine exposure. A decrease in cell metabolic activity was noticed at the highest nicotine concentration (500ng/ml), below that concentration, no significant decrease was observed.

Conclusions: Our findings suggest that nicotine affects PDLF cell viability in a concentration-dependent manner. Nicotine also detrimentally affects cell morphology and induces vacuolization within cells. We observed drastic changes in cell shape (enlargement) and an accumulation of cytoplasmic vacuoles. This study confirms the toxic effect of nicotine on PDLF cells and corroborates the role of nicotine in periodontitis within smokers.