Amoxicillin and Metronidazole During or After the Periodontal Treatment

This randomized clinical trial aimed to compare the clinical and microbiological effects of different times of administration of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of periodontitis.

Scaling and root planing (SRP) is the most used periodontal therapy for periodontal treatment. Despite leading, in most cases, to an improvement in periodontal clinical parameters, SRP is often insufficient to profoundly modify the pathogenic bacterial profile to a profile related to periodontal health, especially in cases of more advanced and generalized diseases. Thus, other therapies supporting SRP, such as systemic antibiotics, have been proposed with the aim of enhancing the clinical and microbiological effects of this form of therapy. Studies have shown excellent clinical and microbiological results using the association of systemic antibiotics, especially the association of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of severe periodontitis. However, some essential issues associated with the use of these antibiotics remain to be established. Therefore, the aim of this randomized clinical trial was to compare the clinical and microbiological effects of different times of administration of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of periodontitis. Seventy-two subjects with severe periodontitis were selected and randomized into two groups (n = 36 / group) - Test 1 (T1): SRP in 14 days, associated with the concomitant use of AMX (500mg, 3x / day) and MTZ (400mg 3x / day) for 14 days; and Test 2 (T2): SRP in 14 days, associated with the use of AMX and MTZ immediately after the end of the SRP in the following 14 days. All volunteers received clinical and microbiological evaluation at baseline, 3, 6 and 12 months post-SRP. Subgingival biofilm samples were collected by subject and analyzed for counts and proportions of 40 bacterial species by checkerboard DNA-DNA hybridization. Differences in clinical and microbiological parameters between groups and over time were evaluated using the ANOVA, ANCOVA, Chi-square and Tukey tests. Microbiological analyzes were performed using adjustments for multiple comparisons. Statistical significance was set at 5%.

Eligibility Criteria:
Inclusion Criteria:

* 18 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 in the previous 6 months;
* antibiotic therapy in the previous 6 months;
* long-term intake of anti-inflammatory medications;
* need for antibiotic pre-medication for routine dental therapy;
* use of orthodontic appliances;
* extensive dental prosthetic rehabilitation;
* allergy to metronidazole and/or amoxicillin.