No evidence on whether antibiotic prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who need invasive dental procedures

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Bacteraemia is common following dental procedures and it was believed that this could lead to bacteria endocarditis a severe infection of the lining of the chambers of the heart with a high mortality rate.  Until 2008 when National Institute for Health and Care Excellence (NICE) recommended that antibiotics were not required guidelines in many countries had recommended their use prior to invasive dental procedures.  This update of a Cochrane review aims to determine whether prophylactic antibiotic administration, compared to no such administration or placebo, before invasive dental procedures in people at risk or at high risk of bacterial endocarditis influences mortality, serious illness or the incidence of endocarditis.

Searches of the Cochrane Oral Health Group’s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE  were conducted with the US National Institutes of Health Trials Register  and the metaRegister of Controlled Trials being searched for ongoing studies.  There were no language restrictions.mIn addition to Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) Cohort and case-control studies were included where suitably matched control or comparison groups had been studied.

  • This update do not identify any new studies so only one case control study met the criteria.
  • This study collected all the cases of endocarditis in the Netherlands over two years.  24 cases were identified who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines, and who were at increased risk of endocarditis due to a pre-existing cardiac problem. Controls were matched for age (within the same five year age category) and had undergone a medical or dental procedure within 180 days of their interview. A random sample of potential controls was drawn, and where there were at least four controls per case all were contacted.
  • No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes.

The authors concluded

There remains no evidence about whether antibiotic prophylaxis is effective or ineffective against bacterial endocarditis in people at risk who are about to undergo an invasive dental procedure. It is not clear whether the potential harms and costs of antibiotic administration outweigh any beneficial effect. Ethically, practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.


There is little evidence to support the use of antibiotic prophylaxis but as the authors note this has led to variations in the guideline recommendations from different groups.  In the UK the impact of the NICE recommendations will be monitored using Hospital Episode Statistics  (HES) but this will only provide limited information. The authors estimate that a two-year RCT would require about 60,000 patients with a cardiac risk factor or a 10-year cohort study with 18,000 participants!


Glenny AM, Oliver R, Roberts GJ, Hooper L, Worthington HV. Antibiotics for the prophylaxis of bacterial endocarditis in dentistry. Cochrane Database of Systematic Reviews 2013, Issue 10. Art. No.: CD003813. DOI: 10.1002/14651858.CD003813.pub4.

Antimicrobial prophylaxis against infective endocarditis, NICE Clinical Guideline (March 2008)

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