Systemic azithromycin as an adjunct to scaling and root planing in patients with stage III/IV periodontitis: 12-month results of a randomized controlled clinical trial.

OBJECTIVES: To determine whether azithromycin (AZI) as an adjunct to scaling and root planing (SRP), when compared to placebo, decreases the number of sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 12 months post-treatment in stage III/IV periodontitis patients. MATERIALS AND METHODS: In a double-blind randomized parallel-arm placebo-controlled trial, 40 stage III/IV periodontitis patients received steps 1 and 2 of periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20; AZI 500 mg/day, 3 days) or placebo (n = 20). Additional instrumentation of residual diseased sites (DS) - sites with PD ≥ 5 mm and BOP - was performed at the 3-, 6- and 9-month follow-ups. The primary outcome variable was the number of DS at the 12-month re-evaluation. Using a multivariate multilevel logistic regression model, the effects of gender, age, antibiotic therapy, presence of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated. RESULTS: The number of DS after 12 months was similar in the test (median (Me) = 4, interquartile range (IQR) = 0-6) and control (Me = 3, IQR = 1-6.5) groups. Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroup differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio (OR) for the healing of DS on molars (OR = 0.29; p < 0.001) and in smokers (OR = 0.36; p = 0.048). CONCLUSION: Stage III/IV periodontitis patients showed significant but comparable improvements in periodontal parameters and the number of residual DS at the 12-month revaluation regardless of treatment type. This may have been the result of the additional instrumentation received by patients at residual DS in both treatment groups. CLINICAL RELEVANCE: Treatment with AZI + SRP provided no additional benefits after 12 months in terms of periodontal parameters or the number of persisting sites with PD ≥ 5 mm + BOP as compared to SRP plus placebo. TRIAL REGISTRATION: EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.

Influence of adjunctive azithromycin on microbiological and clinical outcomes in periodontitis patients: 6-month results of randomized controlled clinical trial.

BACKGROUND: Our aim was to determine if azithromycin therapy, as an adjunct to scaling and root planing (SRP), decreases the number of pathobiontic subgingival plaque species and sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 6 months post-treatment. METHODS: In a double-blind randomized parallel-arm placebo-controlled trial, 40 patients received nonsurgical periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20, azithromycin 500 mg/day for 3 days) or placebo (n = 20). Pooled microbiologic samples were taken before and 6 months after therapy and analysed by established culture methods. The primary outcome variable was the number of sites with PD ≥ 5 mm and BOP at the 6-month re-evaluation. Using multivariate multilevel logistic regression, the effects of gender, age, antibiotic therapy, presence of P. gingivalis or A. actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated. RESULTS: The number of sites with PD ≥ 5 mm and BOP after 6 months was similar in the test (Me = 4, IQR = 0-11) and control (Me = 5, IQR = 1-22) group. Adjunctive azithromycin treatment, compared to SRP alone, resulted in more frequent eradication of A. actinomycetemcomitans (p = 0.013) and C. rectus (p = 0.029), decreased proportion (p = 0.006) and total counts (p = 0.003) of P. gingivalis, and decreased proportion of C. rectus (p = 0.012). Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroups differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio for healing of diseased sites on molars (OR = 0.51; p <  0,001). CONCLUSION: Despite significant changes in numbers of A. actinomycetemcomitans, P. gingivalis and C. rectus, patients with periodontitis do not benefit from adjunctive systemic azithromycin in terms of number of persisting sites with PD ≥ 5 mm and BOP. TRIAL REGISTRATION: EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.