Clinical and microbial evaluation of dental scaling associated with subgingival minocycline in chronic periodontitis subjects.

The aims of this double-blind randomized clinical trial were to evaluate the presence of periodontal pathogens and the clinical response of periodontal pockets treatment to scaling and root planing (SRP) associated with subgingival minocycline (SM). A total of 36 subjects, 26 to 60 years old (40.7 +/- 9.1), who had been previously diagnosed with chronic periodontitis, were included in the present study. Eighteen subjects were selected for the test group (TG), who were treated with SRP plus SM (new treatment), and 18 subjects for the control group (CG) who received SRP plus vehicle (current treatment). Two homologous sites in each subject with a probing depth (PD) > or = 6 mm were chosen. To evaluate the clinical response after treatment, PD was measured at baseline and at 90 days. Microbiological evaluation was performed to detect 7 periodontal pathogens using polymerase chain reaction at baseline, 30, and 120 days. A mean reduction in PD of 2.8 and 2.1 mm was observed in the TG and CG, respectively. At baseline, P. gingivalis was the most prevalent organism in both test (65.8%) and control (48.6%) groups. After 120 days it fell to 30.8% in TG and to 23.1% in CG. There were no statistically significant differences between the test and control groups concerning PD (p > 0.05 by Wilcoxon test) or presence of periodontal pathogens (p > 0.05 by Wilcoxon and chi-square; p > 0.01 by Signal test). The results observed showed that the new treatment was as effective as the current treatment in reducing periodontal pathogens and PD among chronic periodontitis subjects.