Intended for healthcare professionals

Letters Dental procedures, antibiotics, and infective endocarditis

Risk of infective endocarditis after dental procedures is extremely low

BMJ 2017; 359 doi: (Published 16 October 2017) Cite this as: BMJ 2017;359:j4733
  1. Mark Baker, director,
  2. Philip Alderson, consultant clinical adviser
  1. mark.baker{at}

Cahill and colleagues endorse a policy that advocates routinely offering antibiotic prophylaxis to people at high risk of infective endocarditis when they undergo invasive dental procedures.1 They quote their own work to support their view that antibiotic prophylaxis in these patients is very effective but do not acknowledge that their findings were challenged during development of the current NICE guideline.2

They do, however, note that “high risk” patients should be reassured that they have an “extremely low risk” of infective endocarditis after dental procedures—even without antibiotic prophylaxis. They also say that evidence shows that invasive dental procedures are not the main trigger for the majority of cases of infective endocarditis. The large majority of cases of infective endocarditis in the study by Tubiana and colleagues were not associated with any dental procedure.3

As Cahill and colleagues state, no studies show whether a reduction in the incidence of bacteraemia as a result of antibiotic prophylaxis translates into a reduction in the incidence of infective endocarditis. Because the risk of infective endocarditis is extremely low, the number needed to treat would be very high—we estimate that several thousand patients would need to be treated to prevent one case of infective endocarditis.

If the advice of Cahill and colleagues is followed, thousands of patients will be given antibiotics with no chance of benefiting but with the attendant risks of anaphylaxis and increasing antimicrobial resistance.

That the incidence of infective endocarditis is increasing around the world, despite various antibiotic prophylaxis policies, is without doubt. The NICE guideline says that the research community needs to design better epidemiological research to understand the causes of this phenomenon and to propose better preventive strategies. Focusing solely on exposure to invasive dental procedures may distract from that research effort.


  • Competing interests: MB and PA are employees of the National Institute for Health and Care Excellence (NICE), in which capacity they have been directly involved in the development and subsequent review of NICE’s clinical guideline on prophylaxis for infective endocarditis.


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