Clinical and microbiological effects of systemic antimicrobials combined to an anti-infective mechanical debridement for the management of aggressive periodontitis: a 12-month randomized controlled trial.

Aim: To compare the 1-year clinical and microbiological outcomes of an enhanced anti-infective therapy with versus without systemic antimicrobials in patients with generalized aggressive periodontitis (GAP).

Methods: In this 12-month randomized, double-blinded, placebo-controlled trial, 35 individuals assigned to a control (n = 17) or test group (n = 18) received full-mouth supra and subgingival ultrasonic debridement followed by scaling and root planing with chlorhexidine rinsing, brushing, and irrigation. Subjects received either amoxicillin (AMX, 500 mg) + metronidazole (MET, 250 mg) or placebos, TID for 10 days. Subgingival samples were obtained and analysed for their composition by checkerboard. Data were subjected to non-parametric tests.

Results: Both therapeutic protocols resulted in similar significant clinical improvement for most parameters at 1 year (p < 0.01). The AMX + MET group exhibited shallower residual pockets than the placebo (p = 0.05). Most periodontal pathogens decreased, whereas beneficial bacteria increased in counts in both groups over time (p < 0.0012). High levels of some periodontal and other microbial pathogens were associated with disease persistence regardless treatment.

Conclusions: The enhanced anti-infective mechanical therapy is comparable with its combination with systemic AMX+MET for most clinical parameters and for maintaining low levels of periodontal pathogens for up to 1 year after treatment of GAP.