Azithromycin as an adjunct to scaling and root planing in the treatment of Porphyromonas gingivalis-associated periodontitis: a pilot study

P>Objective To evaluate the clinical and microbiological effects of systemic azithromycin as an adjunct to scaling and root planing (SRP) in the treatment of Porphyromonas gingivalis-associated chronic periodontitis. Methods Twenty-nine patients harbouring P. gingivalis were randomized into test and placebo groups. Test patients received SRP plus 500 mg of azithromycin per day (3 days), and control patients received SRP plus placebo. Clinical [plaque and bleeding indexes, probing pocket depth (PPD), clinical attachment level (CAL)] and microbiological data (four-sites pooled samples, processed by culture) were collected at baseline, and 1, 3 and 6 months, post-therapy. Clinical variables were compared by anova, and microbiological variables by chi-square, signed-rank and Wilcoxon tests. Results Fifteen test and 11 placebo patients completed the study. Mean PPD decreased 0.34 mm [95% confidence interval (CI) 0.19-0.49] in the placebo and 0.80 mm (CI 0.57-1.04) in the test group after 6 months. For mean CAL gain, the correspondent figures were 0.29 (CI 0.08-0.49) and 0.76 (CI 0.46-1.05), respectively. The frequency of detection of P. gingivalis decreased significantly (p <= 0.01) in the test group after 1, 3 and 6 months. Conclusions Within the limitations of this study, the adjunctive use of systemic azithromycin in the treatment of P. gingivalis periodontitis demonstrated significant clinical and microbiological benefits when compared with SRP plus placebo.