Benefits of additional courses of systemic azithromycin in periodontal therapy.

The use of systemic antimicrobials such as doxycycline, metronidazole, and azithromycin in conjunction with debridement has achieved results superior to those produced by debridement alone. The purpose of the present study was to determine if previous results could be improved upon by administering repeated doses of azithromycin during the hygiene phase. One hundred patients with moderate to advanced periodontitis were treated with scaling and root planing plus three courses of azithromycin during the hygiene phase. All patients then were re-evaluated and periodontal surgery and/or extractions involving 96 teeth were performed in 32 patients. All patients then entered a maintenance program that lasted up to 192 weeks, with four-month recalls. Clinical parameters were recorded at baseline, at re-evaluation (week 6 after baseline), and at 96 and 192 weeks into maintenance. The results indicated that probing depths, bleeding upon probing, and suppuration were reduced significantly at re-evaluation. In addition, 14 teeth that displayed a Class III mobility at baseline improved to either Class I or Class II . There was no relapse during the maintenance phase. Multivariate analysis after 192 weeks indicated no change in the number of sites that bled upon probing, or had pockets that were 5.0-6.0 mm or ≥ 7 mm. Ninety-five percent of the sites that initially bled upon probing did not do so four years post-treatment. The results indicate that three courses of azithromicin in conjunction with root instrumentation during the hygiene phase led to long-lasting beneficial effects on all clinical parameters for at least 192 weeks.