Clinical and microbiological efficacy of systemic roxithromycin as an adjunct to non-surgical periodontal therapy in treatment of chronic periodontitis. A randomized, double-blinded, placebo-controlled clinical trial.

Purpose: The objective of this randomized clinical trial was to evaluate the clinical and microbiological effects of systemic administration of roxithromycin (RXM) as an adjunct to non-surgical periodontal therapy (NSPT) in the treatment of individuals with moderate to severe chronic periodontitis (CP).

Methods: 70 individuals (38 males and 32 females, aged 25 to 60 years) with moderate to severe CP were randomly allocated into two groups. 35 individuals were allocated to full mouth SRP+RXM while 35 individuals were allocated to SRP+ Placebo group. The clinical parameters evaluated were probing depth (PD), clinical attachment level (CAL), gingival index (GI), plaque index (PI) and % bleeding on probing sites (%BOP) at baseline (B/L), 1-, 3- and 6-month intervals while microbiologic parameters included percentage of sites positive for periodontopathic bacteria A. actinomycetemcomitans, P. gingivalis and T. forsythia at B/L, 3 and 6 months using polymerase chain reaction. RESULTs: Both groups showed improved clinical and microbiologic parameters over 6 months. RXM group showed a statistically significant reduction in mean PD and CAL gain as compared to the placebo group (P < 0.0001). There was reduction in percentage of sites positive for periodontopathic bacteria over the duration of the study in both groups and a statistically significant reduction in the number of sites positive for A. actinomycetemcomitans in RXM group (P < 0.001).