Adjunctive Effect of the Metronidazole: Amoxicillin Antibiotic Combination in the Treatment of GAP

Introduction

The first step in the treatment of generalized aggressive periodontitis (GAP) is a cause-related treatment phase aimed at the reduction and/or elimination of the pathogenic microflora. Adjunctive systemic antibiotics may benefit aggressive periodontitis patients during non-surgical therapy.

Aim

A randomized placebo-controlled, parallel-design, double-blind clinical trial with 6-month follow-up study assessed the adjunctive clinical effect of the administration of systemic amoxicillin and metronidazole in the non-surgical treatment of GAP.

Patient Profile

• Forty-one patients referred to the periodontal clinic of the Eastman Dental Hospital, London
• GAP (according to the criteria of the 1999 international classification (Armitage 1999)
• at least 20 teeth present
• good general health
• age between 16 and 35 when first diagnosed with aggressive periodontal disease

Methods

Patients received a course of full-mouth non-surgical periodontal treatment delivered over a 24 h period using machine-driven and hand instruments

Clinical parameters were collected at baseline, and at 2- and 6-months post-treatment

Intervention

The adjunctive course of systemic antibiotic consisting of 500 mg amoxicillin and 500 mg metronidazole three times a day for an adjunctive day.

Study Outcomes

• Primary outcomes:  Probing Pocket Depth (PPD) reduction in sites with initial PPD >7 mm
• Secondary outcomes: Differences between groups for the

• changes in mean full-mouth PPD and the changes in PPD and life cumulative attachment loss (LCAL) at different initial PPD categories
• changes in Full-mouth plaque score (FMPS) and full-mouth percentage bleeding score (FMBS)
• percentage of sites with PPD reduction or LCAL gain of >2 mm
• percentage of sites that showed LCAL loss >2mm (disease progression)
• percentage of sites with PPD changing from >5 to <4mm and the percentage of sites with PPD changing from <4 to <3mm (need for re-treatment)
• description and frequency of adverse events
• compliance with the systemic medication

Results

• In both the test and the placebo groups, all clinical parameters improved at 2 and 6 months
• Highly significant treatment effects for full-mouth PPD reduction, PPD reduction at 4–6mm pockets and PPD reduction at<7mm pockets at 2 and 6 months

• In addition, the 6-month data showed LCAL gains > 2mm at 25% of sites in test patients compared with 16% in placebo (p=0.028)

• Similarly, PPD reductions of 2mm or more were observed in 30% of sites in test and 21% of sites in placebo patients
• Seventy-four percent of pockets with PPD > 5mm at baseline were 4mm or shallower at 6 months in the test group compared with 54% in the placebo group (p=0.008)
• The effects of both treatments had a large impact on bleeding, and these changes were statistically significant at 2 and 6 months (p<0.001)
• Disease progression at 6 months was observed at 1.5% of the test and 3.3% of sites in test and placebo, respectively (p=0.072)

Conclusions

• The study findings indicated that a 7-day adjunctive course of systemic metronidazole and amoxicillin significantly improved the short-term clinical outcomes of full-mouth non-surgical periodontal debridement in subjects with GAP
• Adjunctive use of systemic amoxicillin plus metronidazole, during full-mouth non-surgical cause-related periodontal treatment (FSR), performed within 24 h, has resulted in significant additional improvements in the clinical conditions of GAP patients when compared with FSR alone
• Patients with generalized aggressive periodontitis may benefit from the adjunctive administration of amoxicillin and metronidazole during the initial phase of periodontal treatment

J Clin Periodontol.2005;32:1096–1107.doi:10.1111/j.1600-051X.2005.00814.x