This guidance is based on the Scottish Dental Clinical Effectiveness Programme guide to drug prescribing in dentistry.
To provide evidence for the guidance a literature review using Medline and Cochrane has been conducted, by Dr Joanne Hooker, up to October 2011 searching for Gingivitis; Antibiotics & dental abscess; Mucosal ulceration; Metronidazole; Oral Inflammation; Microbial flora & oral cavity; Oral hygiene; Oral microbial pathogens; Acute necrotising ulcerative gingivitis; Ludwig’s angina; Dentoalveolar abscess; Mucositis; Odontogenic infection; Antimicrobials & dentistry; Pericoronitis; Periodontal disease; Mouthwash/mouthrinse; Periodontitis; Chlorhexidine; Anti-plaque/anti-gingivival; Hydrogen peroxide; Antimicrobial susceptibility; Saline solution. The rationale was written by Dr Joanne Hooker under the guidance of Dr Cliodna McNulty and reviewed by stakeholders. Where only expert opinion was available, the guidance was based on the literature on the main pathogens and their antimicrobial susceptibility profiles in the UK.
Dosage of antimicrobials recommended in this guidance:
The Scottish Dental Clinical Effectiveness Programme 2011 recommends doses of 250mg amoxicillin or 200mg metronidazole when antimicrobials are appropriate. We recommend a higher dose of 500mg amoxicillin and 400mg metronidazole. The rationale for this is when antimicrobials are considered appropriate, it is important to have sufficient concentrations at the site of infection. For β-lactams such as amoxicillin this is time-dependent (i.e. the time period above the MIC) and 500mg TDS amoxicillin is more likely to attain this. For metronidazole, the killing effect is dose-dependent and the greater the concentrations above the MIC the better. AUC/MIC >70 is only attainable against Bacteroides fragilis with a 400mg dose.
Pericoronitis is the inflammation and infection of perimolar soft tissue, often provoked by emerging molar teeth. Formal expert opinion from the Scottish Dental Clinical Effectiveness Programme 2011 indicates that this condition should be managed by referral to a dentist for local surgical treatment primarily with irrigation or incision and debridement of the lesion. Antibiotics can be added where there is systemic involvement or on-going symptoms. The HPA recommends metronidazole 400mg TDS for 3 days. If metronidazole is not tolerated an alternative is amoxicillin 500mg TDS for 3 days (in adults the dose can be doubled in severe infections). See note above references.
Ellison SJ. The role of phenoxymethylpenicillin, amoxicillin, metronidazole and clindamycin in the management of acute dentoalveolar abscesses – a review. Br Dent J 2009;206:247-62. Drawing from conclusions derived from this British literature review and literature search of over 5,000 references worldwide using Embase, Medline and Cochrane (search criteria antibiotics and dental) this review recommends the use of metronidazole 200mg TDS for 3 days as first line treatment in pericoronitis. The HPA, however, recommends 400mg TDS. See note above references.
Sixou J-L, Magaud C, Jolivet-Gougeon A, Cormier M, Bonnaure-Mallet M. Evaluation of the mandibular third molar pericoronitis flora and its susceptibility to different antibiotics prescribed in France. J Clin Microbiol 2003;12:5794–5797. This French study looked at the microbial flora isolated from samples taken from 35 patients with pericoronitis and evaluated their susceptibility to amoxicillin, pristinamycin (a macrolide) and metronidazole (alone or in combination with the macrolide spiramycin). Obligate anaerobes were isolated in 91% of cases and resistance to metronidazole was not evident in any species. Amoxicillin was highly active against 91.5% of aerobes and anaerobes isolated and therefore in severe
infections amoxicillin can be added to metronidazole.
Dahlen G. Microbiology and treatment of dental abscesses and periodontal-endodontic lesions. Peridontol 2000 2002;28:206-239. (Sweden) This informal expert review evaluated 7 studies looking at the microbial findings in pericoronitis and concluded that anaerobic species predominate, sharing a similar microbiological profile to that of a dental abscess.