Indications for the use of metronidazole in the treatment of non-periodontal dental infections: a systematic review

Background Dental practitioners are the largest prescribers of metronidazole. Antibiotics should only be prescribed when systemic involvement is clear and should be limited to monotherapy with β-lactams in the first instance. Objectives To determine whether metronidazole used as monotherapy or in addition to a β-lactam antibiotic offers any additional benefit over β-lactam monotherapy in non-periodontal dental infections. Methods Searches of Ovid Medline, Ovid Embase, Cochrane library and trials registries, forward and backward citations, for studies published between database inception and 2 August 2021. All randomized clinical trials (RCTs) and non-randomized trials comparing either systemic metronidazole monotherapy or metronidazole combined with a β-lactam with β-lactam monotherapy for the treatment of non-periodontal dental infections in adults or children in outpatient settings were included. Results Four publications reporting three RCTs comparing metronidazole with a β-lactam antibiotic were recovered. Studies were conducted in the 1970s–80s and aimed to demonstrate metronidazole was as effective as penicillin for the treatment of acute pericoronitis or acute apical infections with systemic involvement. Meta-analysis of results was not possible due to differences in measurement of infection signs. All studies concluded that metronidazole and penicillin are equally effective for the treatment of non-periodontal dental infections with systemic involvement. Conclusions Metronidazole does not provide superior clinical outcomes (alone or in combination with a β-lactam) when compared with a β-lactam antibiotic alone for the treatment of non-periodontal dental infections in general dental practice. Guidelines should reinforce the importance of surgical interventions and if appropriate the use of a single agent narrow-spectrum β-lactam.