Near-patient test for nicotine and its metabolites in saliva to assess smoking habit.

Smoking is a major risk factor for periodontal disease, causing bone and tooth loss. Effective management of many oral conditions requires accurate information about smoking. We describe a disposable, 10-min, near-patient saliva test to monitor cigarette smoking. A plastic device contains the dried reagents to measure nicotine and its metabolites by a colorimetric assay. The device can be used to give a semi-quantitative assessment of tobacco consumption by observing a colour change and comparing it to a reference chart. Alternatively, the test can be quantified by measuring the light absorbance with a colorimeter and determining the concentration of nicotine metabolites by reference to a cotinine standard. This method correlates with reported daily cigarette consumption (r=0.62, P<0.0001) and nicotine yield of cigarettes smoked (r=0.35, P<0.01) and compares favourably with cotinine, as measured independently by radioimmunoassay (r=0.57, P<0.005). The method provides a simple-to-use, inexpensive way of monitoring tobacco consumption in dental surgeries.