Sir, we should like to draw readers' attention to a point in the paper by Scully and Felix (BDJ 2005; 199: 565) on oral white patches. The brown discolouration of teeth or lesions in tobacco smokers was referred to as 'nicotine staining' but more accurately it should be referred to as 'tar staining'. Although nicotine is the addictive component of tobacco smoke it is not responsible for the staining or most of the injurious effects of smoking. Tobacco smoke contains at least 4,000 components, some examples of which are given in Table 1. The tar component is responsible for the staining and contains many of the harmful chemicals that are highly carcinogenic. Therefore we should like to reinforce the message that nicotine is not the most harmful component of tobacco smoke, and indeed nicotine replacement therapy has been shown to be very safe. It is probably legitimate to retain the term 'stomatitis nicotina' to describe the changes induced in the palate by smoking, but rather than blame the 'nicotine' one should implicate the combustion products of the tobacco plant Nicotiana.

Table 1 Some constituents of tobacco smoke (http://www.ash.org.uk/)
Full size table