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The effects of adjunctive metronidazole plus amoxicillin in the treatment of generalized aggressive periodontitis: a 1-year double-blinded, placebo-controlled, randomized clinical trial


  • Conflict of interest and source of funding statement

    The authors declare that they have no conflict of interests. This study was supported by Research Grant #2007/55291-9 from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Brazil).


Marcelo Faveri

Centro de Pós-Graduação e Pesquisa-CEPPE

Universidade Guarulhos

Praça Tereza Cristina, 229 Centro

07023-070 Guarulhos, SP





To evaluate the clinical effects of the adjunctive use of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of generalized aggressive periodontitis (GAgP).


Thirty subjects were randomly assigned to receive scaling and root planing (SRP) alone or combined with MTZ (400 mg/TID) and AMX (500 mg/TID) for 14 days. Subjects were clinically monitored at baseline, 6 months and 1 year post-therapies.


Both therapies led to a statistically significant improvement in all clinical parameters at 1 year post-therapy (< 0.05). Subjects receiving MTZ plus AMX exhibited the deepest reductions in mean probing depth (PD) and gain in clinical attachment between baseline and 1 year post-therapy in the full-mouth analysis and in initially intermediate (PD 4–6 mm) and deep (PD≥7 mm) sites (< 0.01). In addition, the antibiotic group presented lower mean number of residual sites with PD≥5 or 6 mm as well as fewer subjects still presenting nine or more sites with PD≥5 mm or three or more sites with PD≥6 mm at the end of the study period.


The non-surgical treatment of GAgP is markedly improved by the adjunctive use of MTZ+AMX, up to 1 year post-treatment.