RESUMO
BACKGROUND: The aim of this study was to evaluate the effect of the association of locally delivered doxycycline 10% and scaling and root planing in the subgingival plaque of smokers. METHODS: Sixteen smokers with chronic periodontitis and a minimum of four pockets (> or = 5 mm) on anterior teeth that bled on probing were selected. Patients were randomly assigned to one of the following groups: scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Subgingival plaque samples were collected from initially moderate (5 to 6 mm) and deep (> or = 7 mm) pockets at baseline and 3 months. Polymerase chain reaction (PCR) analysis was used to detect the frequency of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Tannerella forsythensis (Tf). RESULTS: No statistically significant difference was found in the reduction of Aa in either the SRP-D or SRP group (P > 0.05). The reduction in Tf, Pg, and Tf + Pg was statistically significant for SRP-D only (P = 0.016, 0.027, and 0.027, respectively). The proportion of sites free of Tf at 3 months was 53% for SRP-D and 9% for SRP (P = 0.02). For Pg, this proportion was 82% and 40%, respectively (P = 0.05). CONCLUSION: The use of locally delivered doxycycline may promote the elimination of T. forsythensis and P. gingivalis in a greater proportion of sites compared to conventional scaling and root planing in smokers.
