Evaluation of salivary thiocyanate as an indicator of smoking behavior.

Salivary samples from three placement sites and under stimulated and unstimulated flow-rate conditions were collected from 36 participants (18 smokers, 18 nonsmokers) on each of 3 days. These samples were used to determine the best collection methodology for discriminating smokers from nonsmokers, the reliability of salivary thiocyanate (SCN) over days, and the stability of SCN given varying storage treatments. Results showed that SCN levels were significantly higher in smokers than in nonsmokers, in parotid site collections than either sublingual or mixed collections, and in unstimulated collections. Stimulated, mixed samples were reliable across days and were the best discriminator of smokers and nonsmokers. SCN levels did not differ under varying storage treatments. It is recommended that a standard methodology for collecting stimulated, mixed saliva be used when measuring SCN levels.