Emingil G, Han B, ozdemir G, Tervahartiala T, Vural C, Atilla G, Baylas H, Sorsa T. The effect of azithromycin, as an adjunct to nonsurgical periodontal treatment, on microbiological parameters and gingival crevicular fluid biomarkers in generalized aggressive periodontitis. J Periodont Res 2012; 47: 729739. (c) 2012 John Wiley & Sons A/S Background and Objective: To study the effectiveness of azithromycin in combination with nonsurgical periodontal therapy on clinical and microbiological parameters, and on the MMP-8 and TIMP-1 levels in gingival crevicular fluid, over a 6-mo time-period in patients with generalized aggressive periodontitis. Material and Methods: Thirty-two patients with generalized aggressive periodontitis were included in this randomized, double-blind, placebo-controlled, parallel-arm study. They were randomly assigned to azithromycin or placebo groups (500 mg once daily for 3 d). Probing depth, clinical attachment levels, presence of bleeding on probing and plaque were recorded. Gingival crevicular fluid samples were obtained from one single-rooted tooth, while microbiological samples were obtained from two single-rooted teeth, all with a probing depth of = 6 mm. Microbiological parameters were analyzed by quantitative real-time PCR for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia and total bacteria. Gingival crevicular fluid biomarkers were determined by immunofluorometric assay and ELISA. Results: All clinical parameters improved, and microbiological parameters and gingival crevicular fluid MMP-8 levels significantly decreased, over the 6-mo period (p < 0.05); both groups demonstrated similar improvements. The azithromycin group presented a higher percentage of deep pockets resolved (probing depth reduction of = 3 mm from baseline) compared with the placebo group at 1 mo (p < 0.05). Conclusion: Adjunctive azithromycin therapy provides no additional benefit over nonsurgical periodontal treatment on clinical parameters, microbiological parameters and gingival crevicular fluid biochemical markers investigated in patients with generalized aggressive periodontitis.