Human InterestInfectious DiseasesOffice Practice InfoPreventive MedicineWellness


Twice-yearly visits to the dentist have been my routine since childhood when my mother took me to Dr. Donagh in the Odd Fellows Building in downtown Indianapolis. Regular cleaning and “prophylaxis” have positive benefits, just as did the invention of fluoride toothpaste and the inclusion of fluoride in drinking water. But even with the best preventive care, patients still have problems that require intervention. Crowns, bridges, extractions, fillings, infections, endodontic procedures, biopsies, and the vast array of modern cosmetic dentistry are performed often. These procedures have the potential to seed the bloodstream with bacteria and cause serious infections in the heart or artificial joints in susceptible individuals.

For the past fifty years, physicians and dentists have been concerned that manipulation of the teeth and gums could allow bacteria to get into the bloodstream. The high concentration of blood vessels in the mouth makes it a real possibility. Bacteria in the bloodstream tend to settle in places in the body susceptible to infection. The two most likely places are the inner lining of the heart (more specifically, the surface of the heart valves) and in joints that have been replaced with artificial components. Circulating bacteria find these sites to be an accommodating environment. They can grow and multiply and cause major problems.

Infection of the inner lining of the heart is called endocarditis. It is rare, but it causes severe damage to the heart and heart valves, and may result in the need to replace a damaged valve. Severe endocarditis causes heart failure and can be fatal. Giving the patient antibiotics right before any dental procedure theoretically kills circulating bacteria and prevents endocarditis. 

The same was thought to be true about knees and hips that had been surgically replaced. They were thought to be susceptible to infection from bacteria in the bloodstream after dental work, as well. An infected prosthetic joint is a disaster and always requires removing the “hardware” and months of IV antibiotics. Prophylactic antibiotics given before dental work were intended to prevent such infections. But a “high quality, prospective,….study found that antibiotic prophylaxis does not affect the incidence of prosthetic hip or knee infections.” In 2015, the American Dental Association (ADA) changed their recommendation.

So, what is recommended in today’s medical world? When and why should antibiotics be given before dental work? Current indications are listed below.

Endocarditis:  Pre-procedure antibiotics are recommended only for the following situations:

     1. Patients who have artificial heart valves or valves repaired surgically

     2. Patients with a previous history of infectious endocarditis

     3. Patients with un-repaired congenital heart disease

     4. Patients with previous congenital heart disease surgery—shunts, patches

     5. Heart transplant patients with abnormal heart valve function

Essentially, prophylactic antibiotics are not recommended for heart infection prevention unless you have one of the circumstances listed above. 

Prosthetic Joints:  Because of the study cited above, the ADA and the American Academy of Orthopedic Surgeons jointly recommended discontinuing the routine use of prophylactic antibiotics in patients with prosthetic joints. No longer is it necessary to take antibiotics before dental work if you have had a hip or knee replacement. 

Dr. G’s Opinion: These recommendations are a big change from a policy in place for fifty years. I agree with the joint replacement recommendation, but have reservations about the endocarditis conclusion. Here’s why:

Joint replacement justification—“9 studies….showed very low quality of evidence….that the use of antibiotic prophylaxis reduces the incidence of [infection]…..and concluded that [it] should be discouraged in dental proceedings.” ie. It doesn’t help so why do it. 

Endocarditis justification—“36 studies were reviewed….[scientists] used bacteremia (bacteria in the bloodstream) as an endpoint….[results] indicate that antibiotic prophylaxis is effective in reducing the incidence of bacteremia, but….this may not translate to…significant protective effect against endocarditis in patients at low risk of disease.” They’re saying antibiotics reduce bacterial spread in the bloodstream, but this doesn’t directly correlate with fewer cases of endocarditis. That places an asterisk next to the endocarditis recommendation. However, the patients with heart disease for whom antibiotics are recommended are the ones most at risk and most in need. With this recommendation, it then seems like little has changed. Antibiotics were always recommended in these situations. Whereas, those patients with murmurs, stents, coronary bypasses, heart failure and coronary disease, who were recommended for prophylactic antibiotics before, no longer need them. They are now recommended to do without. Anything that disrupts the flow of blood through the heart, or causes turbulence in the heart, has the potential to cause endocarditis, so I still wonder if antibiotics are needed. But wiser folks than I have looked at this subject in detail. If they say “no,” who am I to disagree.

References: Herrick KR, Terrio JM, Herrick C. Medical Clearance for Common Dental Procedures Am Fam Phys 2021 Nov;104(5):476-483.

Dayer M, Thornhill M. Is antibiotic prophylaxis to prevent endocarditis worthwhile? J Infect Chemotherapy 2018 Jan;24(1):18-24.

Rademacher WMH, et al. Antibiotic prophylaxis is not indicated prior to dental procedures for prevention of periprosthetic joint infections. Acta Orthop 2017 Oct;88(5):568-574.

Cahill TJ, et al. Antibiotic prophylaxis for infective endocarditis: a systematic review and meta-analysis. Heart 2017 Jun;103(12):937-944.

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