Outcomes associated with supportive periodontal therapy in smokers and nonsmokers

This study evaluated the effects of smoking status on retrospective clinical and radiographic measures of periodontal disease and compared these to prospective changes in digital radiographic bone height.

Clinical data on moderate (4 to 6 mm) and severe (> 6 mm) periodontal pocket depths, and bleeding on probing, were obtained from 95 subjects on suggested three-month supportive periodontal therapy (SPT) for AAP Class III/IV periodontitis. Standardized radiographic data were obtained concerning posterior interproximal alveolar bone height from 36 of the 95 subjects using computer-assisted digital technology at baseline and one year later. The subjects were divided into groups by smoking status: current, former, and never. Data were evaluated using a general linear statistical model.

Evaluation of clinical data showed that current smokers exhibited a significantly higher percentage of moderate (18%) and severe (1%) periodontal pockets than nonsmokers (10% and 0%, respectively; p < 0.002). Baseline radiographic interproximal bone height loss also was greater in current smokers (5.75 +/- 1.07 v. 4.64 +/- 1.16 mm). Bone loss over one year occurred in 5% of the sites, but was not significantly different among groups.

Clinical periodontal pockets and bone loss accumulated more rapidly in smokers, even though they submitted to regular supportive periodontal therapy. Although this population was clinically compliant over a one year period, digital radiography showed a high incidence of detectable bone loss. The impact of smoking, however, may require longer than one year to show longitudinal changes. It is recommended that a periodic radiographic analysis on bone height be considered during SPT, and longer term studies be conducted in order to accurately identify the outcome of smoking status on this variable.