Dose and Duration of Metronidazole and Amoxicillin for Treatment of Chronic Periodontitis

Impact of Different Dosages and Time of Administration of Metronidazole and Amoxicillin in the Treatment of Generalized Chronic Periodontitis: A Randomized Clinical Trial

The aim of this study was to compare the clinical and microbiological outcomes of different dosages of metronidazole (MTZ) and of the duration of the systemic administration of MTZ and amoxicillin as adjunct to scaling and root planing (SRP) in the treatment of generalized chronic periodontitis (GChP).

Randomized clinical trials and systematic reviews have shown that the use of the combination of metronidazole (MTZ) and amoxicillin (AMX) significantly improves the benefits of the SRP in the treatment of subjects with periodontitis. However, the optimal dosage and interval of administration of these antibiotics are still unclear. Therefore, the aim of this study was to compare the clinical and microbiological outcomes of different dosages and duration of the systemic administration of the combination of MTZ and AMX as adjunct to scaling and root planing (SRP) in the treatment of generalized chronic periodontitis (GChP). One hundred ten subjects will be randomly assigned to receive SRP plus placebo, or SRP combined with 250 mg or 400 mg of MTZ, plus AMX (500 mg) TID, for either 7 or 14 days. Subjects will be clinically and microbiologically monitored up to 1 year post-therapy.

Inclusion Criteria:

• ≥30 years of age;
• at least 15 teeth (excluding third molars and teeth with advanced decay indicated for extraction)
• a minimum of 6 teeth with at least one site each with probing depth (PD) and clinical * attachment level (CAL) ≥5 mm;
• at least 30% of the sites with PD and CAL ≥4 mm and bleeding on probing (BOP).

Exclusion Criteria:

• pregnancy
• breastfeeding
• current smoking and former smoking within the past 5 years;
• systemic diseases that could affect the progression of periodontitis (e.g. diabetes, immunological disorders, osteoporosis);
• scaling and root planing an in the previous 12 months;
• antibiotic therapy in the previous 6 months;
• long-term intake of anti-inflammatory medications;
• need for antibiotic pre-medication for routine dental therapy;
• allergy to metronidazole and/or amoxicillin.