nucleolar organizer regions of oral epithelial cells in crack cocaine users

background: the health risks of crack cocaine smoking on the oral mucosa has not been widely researched and documented. objective: the purpose of this study was to analyze the proliferative activity of oral epithelial cells exposed to crack cocaine smoke using silver nucleolar organizer region (agnor) staining. methods: oral smears were collected from clinically normal-appearing buccal mucosa by liquid-based exfoliative cytology of 60 individuals (30 crack cocaine users and 30 healthy controls matched for age and gender) and analyzed for cytomorphologic and cytomorphometric techniques. results: crack cocaine users consumed about 13.3 heat-stable rocks per day and the time consumption of the drug was of 5.2 (± 3.3) years. mean values of agnor counting for case and control groups were 5.18 ± 1.83 and 3.38 ± 1.02 (p<0.05), respectively. agnor area and percentage of agnor-occupied nuclear area were increased in comparison with the control (p<0.05). there was no statistically significant difference in the mean values of the nuclear area between the groups (p>0.05). conclusion: this study revealed that crack cocaine smoke increases the rate of cellular proliferation in cells of normal buccal mucosa.