Systemic antimicrobials adjunctive to a repeated mechanical and antiseptic therapy for aggressive periodontitis: a 6-month randomized controlled trial

J Periodontol. 2011 Aug;82(8):1121-30. doi: 10.1902/jop.2011.100656. Epub 2011 Jan 14.


Background: The purpose of this study is to compare the additional benefit of systemic antimicrobials versus placebos to a repeated mechanical instrumentation combined with comprehensive local chemical plaque control for the periodontal treatment of generalized aggressive periodontitis (GAgP).

Methods: This was a 6-month randomized, double-masked, placebo-controlled clinical trial. All GAgP patients received full-mouth disinfection followed by staged scaling and root planing without (placebo group; n = 17) or with (test group; n = 18) systemic antimicrobials (500 mg amoxicillin [AMX] + 250 mg metronidazole [MET]; three times a day for 10 days). Clinical parameters were measured at baseline and 3 and 6 months post-therapy. Significant differences between groups at baseline were sought by using the Mann-Whitney U test, whereas comparisons over time were examined by using a general linear model repeated measures procedure.

Results: Both groups demonstrated similar improvements in most parameters over time. The test group presented a greater mean probing depth (PD) reduction and clinical attachment level (CAL) gain at sites with initially moderate PD at 6 months (P <0.03). No differences were seen between groups regarding mean reductions and mean gains, respectively, for PD and CAL initially ≥7 mm. The test group presented a higher percentage of sites that improved ≥2 mm and ended up with PD ≤4 mm or a lower percentage of sites that worsened ≥2 mm and remained with PD >4 mm at 3 months (P <0.01). No differences were noticed between groups for these parameters at 6 months.

Conclusion: AMX + MET brought additional clinical effects to the repeated mechanical and antiseptic treatment of GAgP in a very short time (3 months), which tended to fade away over time (6 months).

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aggressive Periodontitis / complications
  • Aggressive Periodontitis / therapy*
  • Amoxicillin / therapeutic use
  • Anti-Infective Agents / therapeutic use*
  • Combined Modality Therapy
  • Dental Plaque / complications
  • Dental Plaque / prevention & control*
  • Dental Scaling*
  • Double-Blind Method
  • Drug Combinations
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Metronidazole / therapeutic use
  • Retreatment
  • Statistics, Nonparametric
  • Time Factors
  • Treatment Outcome
  • Young Adult


  • Anti-Infective Agents
  • Drug Combinations
  • Metronidazole
  • Amoxicillin