Systemic Antimicrobials Adjunctive to a Repeated Mechanical and Antiseptic Therapy for Aggressive Periodontitis: A 6‐Month Randomized Controlled Trial

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).