Clinical Update

Dental Treatment and Bacterial Endocarditis

Editor's note: Many readers may have seen a recent study indicating that dental treatment is not a significant risk for bacterial endocarditis. To determine implications of the study on the use of antibiotic prophylaxis in certain patients, we contacted Dr. Thomas Pallasch, a co-author of the 1997 Endocarditis Prevention Recommendations, and asked him to clarify the issue.

Considerable interest has been expressed in the recent study by Strom and colleagues in the Annals of Internal Medicine1 indicating that dental treatment procedures may not pose a significant risk for the development of bacterial endocarditis. The authors studied 273 adults who had a definite, probable or possible diagnosis of infective endocarditis with a matched group of control individuals without the disease. Both groups had approximately the same exposure to dental treatment over the three months prior to the diagnosis of endocarditis in the case-control group, from which the authors then concluded that dental treatment was not a factor in the acquisition of endocarditis. Dental extractions were performed in six patients with endocarditis and none of the controls, but the extractions were not included in the study protocol. Interestingly, any endocarditis attributable to viridans streptococci, alpha-hemolytic streptococci (not Group D), anaerobes, and HACEK organisms (Haemophilus influenzae, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens and Kingella kingae) was considered to have originated from the oral cavity, even though most of these organisms also reside elsewhere in the body. The authors did detect a strong relationship between cardiac valvular defects and the development of endocarditis.

This study can now be added to other clinical studies,2,3 analyses4,5 and commentaries6-11 that also either found a low or no correlation between dental treatment and endocarditis or questioned the mass unqualified use of antibiotic prophylaxis in an attempt to prevent endocarditis in dental patients. These studies, analyses and commentaries were considered in preparing the 1997 American Heart Association (AHA) endocarditis prevention guidelines (as was this study by Strom, which was referenced as an abstract). They were also considered in the recommendation for a reduction in dental procedures requiring prophylaxis, as reflected in the following statement: "The vast majority of endocarditis due to oral organisms is not related to dental treatment procedures."12

In an accompanying editorial analyzing the Strom study and the previous analyses and commentaries cited above, David Durack has proposed that future AHA endocarditis prevention guidelines be primarily limited to patients with very high risk medical conditions (cardiac prosthetic valves, previous endocarditis) who undergo any of only three dental procedures (extractions, gingival surgery and/or implants).13 The Strom study did not include children, and it is likely that complex cyanotic congenital heart disease would also be included for prophylaxis. Durack made it clear that "The concept of prophylaxis is valid and should be retained, but in a restricted and better-focused form."

The AHA has prepared the following statement:

"The American Heart Association Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease reviewed 'Dental and Cardiac Risk Factors of Infective Endocarditis,' published in the Nov. 15 issue of the Annals of Internal Medicine, with great interest and appreciation for the extensive clinical data collection that it represents. The committee's ongoing mission is to refine the criteria for endocarditis prophylaxis to maximize benefit and minimize risk. The committee believes that the AHA's published guidelines, which are described in the AHA Medical/Scientific Statement titled 'Prevention of Bacterial Endocarditis' remain valid in the face of these results and does not recommend changes in practice or patient education at this time. This study and others will be assessed in conjunction with previously available data in future discussions regarding prophylaxis guidelines."

Simply put, things remain as they are. Future AHA guidelines may, as they have in the past, be suitably revised as new documented data dictates. Until then, dentists should continue to follow the current 1997 AHA guidelines for the prevention of bacterial endocarditis.12

Dr. Pallasch is a member of the American Heart Association Commmittee on Rheumatic Fever, Endocarditis, and Kawasaki Disease. This article is not an official publication of the American Heart Association.

1. Strom BL, Abrutyn E, et al, Dental and cardiac risk factors for infective endocarditis: A population-based, case-control study. Ann Int Med 129(10):761-9, 1998.

2. Lacassin F, Hoen B, et al, Procedures associated with infective endocarditis in adults: A case control study. Europ Heart J 16(12):1968-74, 1995.

3. Van der Meer JT, Thompson J, et al, Epidemiology of bacterial endocarditis in the Netherlands, II: Antecedent procedures and use of prophylaxis. Arch Int Med 152(9):1869-73, 1992.

4. Bayliss R, Clarke C, et al, The teeth and infective endocarditis. Brit Heart J 50(6):506-12, 1983.

5. Guntheroth WG, How important are dental procedures as a cause of infective endocarditis? Am J Cardiol 54(7):797-801, 1984.

6. Kaye D, Prophylaxis for infective endocarditis: an update. Ann Int Med 104(3):419-423, 1986.

7. Oakley CM, Controversies in the prophylaxis of infective endocarditis: A cardiological view. J Antimicrob Chemother 20(SA):99-104, 1987.

8. Pallasch TJ, A critique of antibiotic prophylaxis. J Cal Dent Assoc 14(5):28-36, 1986.

9. Pallasch TJ, A critical appraisal of antibiotic prophylaxis. Int Dent J 39(3):183-96, 1989.

10. Pallasch TJ, Slots J, Antibiotic prophylaxis and the medically compromised patient. Periodontol 2000 10(1):107-38, 1996.

11. Wahl MJ, Myths of dental-induced endocarditis. Arch Inn Med 154(2):137-44, 1994.

12. Dajani AS, Taubert KA, et al, Prevention of bacterial endocarditis: Recommendations by the American Heart Association. J Am Med Assoc 277(22):1794-1801, 1997.

13. Durack DT, Antibiotics for the prevention of endocarditis during dentistry: Time to scale back? Ann Int Med 129(10):829-30, 1998.