Effects of smoking on oral ecology. A review of the literature.

The smoking habit is associated with a variety of deleterious changes in the mouth. In this review, the toxicology of tobacco smoke and its effects on the saliva, oral commensal bacteria and fungi, and oral polymorphonuclear leukocytes, are described. Smoking increases salivary flow rate, but does not alter the composition of plaque or its rate of deposition. Smoking appears to enhance anaerobiosis in the oral cavity, and depress the activity of oral leukocytes. Additionally, tobacco smoke components may have a selective toxic effect on particular species of microbiota. Gingival fluid exudate is reduced in smokers, with the consequence that the carriage of leukocytes and immunoglobulins is likely to be diminished.