THE EFFECT OF SMOKING ON MECHANICAL AND ANTIMICROBIAL PERIODONTAL THERAPY

THE AIM OF THIS INVESTIGATION was to evaluate the effect of smoking on the outcome of periodontal therapy. The study consisted of 54 patient s who participated in a 4-group parallel-arm clinical trial on the eff icacy of three locally delivered antimicrobial systems as adjuncts to scaling and root planing in the treatment of sites with persistent poc keting after a course of scaling and root planing. These groups includ ed scaling and root planing either alone (S) (n = 3), or in conjunctio n with the application of 25% tetracycline fibers (S&T) (n = 13), 2% m inocycline gel (S&Mi) (n = 14), or 25% metronidazole gel (S&Me) (n = 1 4). In each patient four pockets > 5 mm with bleeding on probing (BOP) and/or suppuration were studied. The number of subjects who smoked wa s: 8 (61.5%) in the S&T group, 8 (57.1%) in the S&Mi group, 6 (42.9%) in the S&Me group, and 6 (46.2%) in the 8 group. The probing depth, at tachment level and other clinical parameters were assessed at baselin e and 6 weeks after treatments. The clinical results of this comparati ve study have been previously reported. Regardless of the type of trea tment, the change in the probing depth (Delta PD) and attachment gain (Delta AL) were greater in non-smoker subjects than smoker subjects. D elta PD was 1.14 mm versus 0.76 mm (P = 0.019), and Delta AL was 0.52 mm versus 0.50 mm at (P = 0.845) for non-smokers and smokers respectiv ely. The analysis of variance using the general linear model (GLM) was used for Delta PD and Delta AL and took into account the variations i n the treatments, number of smoker subjects per group, and baseline pr obing depth. There was a significant interaction between the ''smoking '' and the ''baseline PD.'' Further analysis using linear regression i ndicated that, while there was a significant relationship between the baseline PD and the Delta PD or Delta AL among the non-smokers, weak a nd insignificant relationship existed among the smoker subjects. Thus, smoking may have an important role in determining the prognosis of pe riodontal treatment, particularly in persistent and deep pockets.