Effects of Nicotine and Tobacco Extract on Tooth-Supporting Alveolar Bone

Nicotine has been considered as the major active ingredient related to the pathogenesis of tobacco-related periodontal bone loss. Nicotine-free cigarettes, manufactured from genetically modified tobacco, are supposed to be less hazardous. Objective: This study was designed to evaluate whether and to which extent, nicotine and tobacco extract, used singly or in combination, may affect tooth-supporting alveolar bone in an experimental animal model. Methods: Eighty-eight Wistar male rats were randomly assigned to one of the following groups: nicotine (n=19), tobacco extract (n=21), nicotine + tobacco extract (n=22) and control (n=19). The animals were exposed to nicotine and tobacco extract added to drinking water, singly or in combination according to the treatment group, for a 63-day period, except for the control group who received plain water. After 42 days, a 0.20mm orthodontic ligature wire was ligated around the upper right first molar to induce periodontitis. At the end of the experimental period, the animals were killed and the maxillae removed for marginal bone evaluation.Results: Data analysis demonstrated that nicotine and nicotine + tobacco extract exposed animals presented increased marginal alveolar bone loss as compared to the tobacco and control groups (p<0.01) and this effect was also noticeable on non-ligated teeth (p<0.01). Nicotine intake was also associated with increased loss of body weight and decreased liquid consumption. Conclusion:

Nicotine, and not tobacco extract, plays a leading role on the prevalence and severity of marginal alveolar bone loss often associated with smoking related periodontal disease.