As she has gotten older, Liz has begun to dread her twice-annual visit to the dentist for an exam and routine cleaning. Years ago, her discharge papers for hip replacement surgery indicated she should expect her dentist to prescribe antibiotics before each visit to prevent infection in her prosthetic joint, a use of antibiotics called antibiotic prophylaxis (AP). When her dentist said she no longer needed AP, it was a relief. Liz had developed a penicillin allergy, and the preferred alternative (clindamycin) gave her cramps and mild diarrhea (1). She was glad to know that her dental visits would focus on her oral health, not her artificial joint.
Last year, Liz had heart valve surgery. Her surgeon told her she was at risk for developing an infection in her heart called infective endocarditis (IE) and that AP was vital before any dental visit. IE is fatal 30% of the time, so prevention is a priority (2). The surgeon explained that, while a dental cleaning is important to maintaining oral health, it allows bacteria such as Staphylococcus aureus and viridans group streptococci that normally live in our mouth, to migrate into the bloodstream. These bacteria travel through the body and can cause IE (3). The use of AP to prevent IE became the standard of care in 1955 (4). For similar reasons, orthopedic surgeons prescribed AP to prevent these bacteria from infecting prosthetic joints (5). This is why Liz was prescribed AP in the years following her hip replacement and was now being prescribed antibiotics to protect her heart. Liz found these changes rather confusing and contradictory and asked her dentist why the rules kept changing.
Her dentist explained that as antibiotic usage became more and more common, doctors have increasingly focused on the impact of AP on the natural gut microbiome, the occurrence of adverse drug reactions, and the rising prevalence of antibiotic-resistant bacteria (6,7). For all of these reasons, efforts were made to quantify the risk of IE and eliminate unnecessary use of AP.
From 2005 through 2010, dentists were responsible for about 10% of all antibiotic prescriptions in the US (8). In 2007, the American Heart Association, in partnership with the American Dental Association and similar groups, released new guidelines that recommended AP only in high-risk patients (9). High-risk patients include those with prosthetic heart valves, previous history of IE, a history of congenital heart disease, and individuals who received a heart transplant and developed heart valve disease (10).
Scientists reasoned that eliminating unnecessary use of antibiotics would reduce the selective pressures that give rise to antibiotic-resistant bacteria. Limiting antibiotic use also reduces the risk of adverse drug reactions and protects the intestinal microbiome. Given the rarity of IE, the risks from AP were actually greater than the risks of IE.5 In fact, there is limited evidence that AP is effective at preventing IE.9,11 There is no evidence even quantifying the risk of IE resulting from a dental procedure.9,10 There is also no evidence that AP protects prosthetic joints.5 Scientists now know that AP is potentially beneficial to a very small group of patients.
Many studies have traditionally assessed the presence of bacteria in the blood (bacteremia) as a way to determine the risk of IE and prosthetic joint infections (5,9), but there are no double-blinded controlled studies showing that bacteremia is predictive of developing IE (9). In fact, bacteremia is commonly caused by routine activities like eating and tooth brushing, so using bacteremia assays after dental procedures to predict infection risk are falling out of favor (9,11). Since bacteremia is a poor predictor of IE and the risks of antibiotic overuse are well understood, the use of AP has changed not just in the United States, but around the world.
While the United States was adopting new guidelines for AP, which were issued 2007, other countries were making similar changes to prescribing habits. Unfortunately, given the rarity of IE and ethical concerns, there are no prospective, controlled studies proving a link between dental procedures and IE, much less the effectiveness of AP at preventing these infections (10). Even so, these policy changes provide an opportunity to evaluate AP effectiveness in different countries. That information is useful to scientists who update the guidelines used in the United States.
The American Dental Association currently recommends AP only for high-risk patients.10 High-risk patients include individuals with prosthetic heart valves or other heart material, some types of congenital heart defects that were treated with prosthetics, and individuals with previous instances of IE. These guidelines are based on information collected from around the world, as different institutions adopted different AP policies. In the United Kingdom, the elimination of all AP correlated with an increase of IE cases, but a directly causative link was not established (2,12). In Taiwan, AP is no longer recommended before dental visits even in high-risk patients (5), and the incidence of IE has remained stable (13). As AP has decreased in the US, data show no increased risk for IE in low and moderate-risk patients (14). All of these studies and results were considered when the American Heart Association reviewed the 2007 AP guidelines in 2021, and the policy of limiting AP to high-risk patients was affirmed (10).
At her last dental visit, Liz talked to her dentist about how much the guidelines have changed over time and questioned whether AP was truly necessary. She dreaded the side effects of clindamycin. Her dentist assured her that the changing practices were reflective of new understanding. If her only risk factor was her artificial hip, AP would not be appropriate. Since Liz had undergone heart valve surgery, she is now a high-risk patient. However, clindamycin is no longer the preferred alternative to penicillin (10), and her dentist prescribed a different antibiotic that would not interfere with other medications Liz was taking.
If you are like Liz and have received conflicting instructions or are concerned about your risks of developing IE following a dental procedure, talk to your healthcare provider about your personal health history. Your healthcare provider will explain the current guidelines and determine whether AP is appropriate for you.
- Jacalyn Newman, Ph.D.
References
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2. Thornhill MH, Crum A, Rex S, et al. Infective endocarditis following invasive dental procedures: IDEA case-crossover study. Health Technol Assess. May 2022;26(28):1-86. doi:10.3310/nezw6709
3. Rajani R, Klein JL. Infective endocarditis: A contemporary update. Clin Med (Lond). Jan 2020;20(1):31-35. doi:10.7861/clinmed.cme.20.1.1
4. Prevention of rheumatic fever and bacterial endocarditis through control of streptococcal infections. Pediatrics. May 1955;15(5):642-6. doi:10.1542/peds.15.5.642
5. Goff DA, Mangino JE, Glassman AH, Goff D, Larsen P, Scheetz R. Review of Guidelines for Dental Antibiotic Prophylaxis for Prevention of Endocarditis and Prosthetic Joint Infections and Need for Dental Stewardship. Clin Infect Dis. Jul 11 2020;71(2):455-462. doi:10.1093/cid/ciz1118
6. Lange K, Buerger M, Stallmach A, Bruns T. Effects of Antibiotics on Gut Microbiota. Dig Dis. 2016;34(3):260-8. doi:10.1159/000443360
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8. Suda KJ, Roberts RM, Hunkler RJ, Taylor TH. Antibiotic prescriptions in the community by type of provider in the United States, 2005-2010. J Am Pharm Assoc (2003). Nov-Dec 2016;56(6):621-626.e1. doi:10.1016/j.japh.2016.08.015
9. Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. Oct 9 2007;116(15):1736-54. doi:10.1161/circulationaha.106.183095
10. Wilson WR, Gewitz M, Lockhart PB, et al. Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association. Circulation. May 18 2021;143(20):e963-e978. doi:10.1161/cir.0000000000000969
11. Glenny AM, Oliver R, Roberts GJ, Hooper L, Worthington HV. Antibiotics for the prophylaxis of bacterial endocarditis in dentistry. Cochrane Database Syst Rev. Oct 9 2013;(10):Cd003813. doi:10.1002/14651858.CD003813.pub4
12. Thornhill MH, Crum A, Campbell R, et al. Temporal association between invasive procedures and infective endocarditis. Heart. Jan 11 2023;109(3):223-231. doi:10.1136/heartjnl-2022-321519
13. Chen TT, Yeh YC, Chien KL, Lai MS, Tu YK. Risk of Infective Endocarditis After Invasive Dental Treatments: Case-Only Study. Circulation. Jul 24 2018;138(4):356-363. doi:10.1161/circulationaha.117.033131
14. Bergadà-Pijuan J, Frank M, Boroumand S, et al. Antibiotic prophylaxis before dental procedures to prevent infective endocarditis: a systematic review. Infection. Feb 2023;51(1):47-59. doi:10.1007/s15010-022-01900-0
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