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, 500mg) + metronidazole (MET, 250mg) or placebos, TID for 10days. 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.