Dental Hypotheses

ORIGINAL HYPOTHESES
Year
: 2012  |  Volume : 3  |  Issue : 2  |  Page : 76--78

Antibiotic prophylaxis in infective endocarditis: Use or abuse?


Nisha Thakur, Narotam Ghezta 
 Department of Dental Health Services, Deen Dayal Upadhaya Hospital, Shimla, Himachal Pradesh, India

Correspondence Address:
Nisha Thakur
Room No-30, Dental OPD, Deen Dayal Upadhaya Hospital, Shimla, Himachal Pradesh
India

Abstract

Introduction: The American Heart Association (AHA) recommendations for antimicrobial prophylaxis for infective endocarditis (IE) are controversial. According to the new guidelines released by the AHA now, the only patients to receive antibiotics will be those at highest risk, i.e. those with a prosthetic heart valve, a history of endocarditis, certain forms of congenital heart disease or valvulopathy after heart transplantation, and only before certain dental procedures. Unfortunately, these guidelines are still based largely on expert opinion, with very little hard evidence to show that antibiotic therapy actually prevents IE. The Hypothesis: The reported incidence of bacteremia during dental intervention ranges from 10% to 100% and, with daily brushing and flossing, from 20% to 68%. Because bacteremia also occurs during brushing and flossing of teeth, why give prophylaxis just for dental procedures? Moreover, the risks of causing adverse or anaphylactic reactions from antibiotics as well as contributing to the nationwide antibiotic resistance problem are issues not to be taken lightly. Evaluation of the Hypothesis: The hypothesis discusses the AHA recommendations for antimicrobial prophylaxis for IE, indicating some inherent limitations associated with it, and stresses upon the fact that these recommendation should also be updated, if not completely changed, to cope up with the advancements in the proper treatment plan.



How to cite this article:
Thakur N, Ghezta N. Antibiotic prophylaxis in infective endocarditis: Use or abuse?.Dent Hypotheses 2012;3:76-78


How to cite this URL:
Thakur N, Ghezta N. Antibiotic prophylaxis in infective endocarditis: Use or abuse?. Dent Hypotheses [serial online] 2012 [cited 2019 Jul 22 ];3:76-78
Available from: http://www.dentalhypotheses.com/text.asp?2012/3/2/76/100393


Full Text

 Introduction



The American Heart Association (AHA) recommendations for antimicrobial prophylaxis for Infective Endocarditis (IE) are controversial. According to the new guidelines released by the AHA now, the only patients to receive antibiotics will be those at highest risk, i.e. those with a prosthetic heart valve, a history of endocarditis, certain forms of congenital heart disease or valvulopathy after heart transplantation, and only before certain dental procedures. Unfortunately, these guidelines are still based largely on expert opinion, with very little hard evidence to show that antibiotic therapy actually prevents IE [1] [Table 1].{Table 1}

Several mechanisms have been proposed to describe the manner in which antibiotics prevent bacterial endocarditis. One hypothesis postulates that antibiotics may confer protection against bacterial endocarditis by reducing the incidence and the magnitude of bacteremia after certain procedures thus decreasing the chances that circulating bacteria will colonize the damaged valvular endothelium in subjects at risk of developing endocarditis. [2]

Human oral cavity is colonized by a larger variety of bacterial flora than any other anatomic area. More than 700 species of bacteria have already been identified, 400 of which were found in the periodontal pocket adjacent to teeth. Streptococci represent a significant proportion of the flora around the teeth, especially in the supragingival plaque, and they are frequently associated with IE. [3]

Over the past 30 years, the overall incidence of IE has remained between 2 and 6 per 100,000 individuals in the general population per year, and the associated mortality has remained between 10% and 30%, depending on the type of pathogen (e.g., oral streptococci are less aggressive than Staphylococcus aureus), the underlying condition, and whether the infection occurs on a native or prosthetic heart valve. [4]

Any breach in the oral mucosal barrier places the internal body environment in contact with a highly contaminated ecosystem, resulting in the penetration of microorganisms into the bloodstream. [5] There are many reports that address bacteremia from dental extractions, which is considered the most invasive of dental office procedures. Bacteremia is also produced by routine daily activities such as tooth brushing, dental flossing, tooth picks and other routine daily events like chewing food, chewing gums, etc. [3],[5]

A sequential relationship between dental procedures and IE can be demonstrated in only 4-7.5% of the cases. Most cases of IE are not preceded by dental procedures. [1]

The aim of our article is to calls into question the appropriateness of antibiotic prophylaxis for dental procedures.

 Hypothesis



At first glance, the recommendations of antimicrobial prophylaxis for IE given by the AHA look justified, but close screening points out some of the inherent drawbacks associated with these recommendations.

Antibiotic prophylaxis recommendations for the prevention of IE are based in part on studies of bacteremia from dental procedures, but tooth brushing may pose a greater threat. [3]

Transient bacteremia occurs commonly, not only during dental procedures that cause trauma to the mucosal surfaces or tissue but also with daily activities such as brushing teeth and chewing. The reported incidence of bacteremia during dental intervention ranges from 10% to 100%, and, with daily brushing and flossing, from 20% to 68%. [1]

Bacteria commonly gain entrance to the circulation through ulcerated gingival crevicular tissue that surrounds the teeth. [3] Some oral microorganisms pass into the bloodstream and colonize areas of valvular endothelium on an earlier sterile incipient vegetation made up fibrin and platelet deposits and cause damage. [6] Of a great variety of gingival microorganisms circulating in the blood after dental manipulation, only those able to attach to damaged valves (streptococci and S. aureus) produced IE. Bouts of transient bacteremia also occur during normal activities such as chewing and tooth-brushing. These instances of bacteremia are usually of low grade and short duration (1-100 colony-forming units [CFU]/mL of blood for less than 10 min), but they are recurrent. The cumulative exposure to circulating bacteria (in CFU/mL of blood per year) has been calculated to be more than 100,000-times greater during physiological activities than after a single tooth extraction, which could explain why most cases of IE occur independently of prior medico surgical procedures. [4]

Because bacteremia occurs also during brushing and flossing of teeth, why give prophylaxis just for dental procedures? Moreover, the risks of causing adverse or anaphylactic reactions from antibiotics, as well as contributing to the nationwide antibiotic resistance problem, are issues not to be taken lightly. [1]

 Evaluation of the Hypothesis



The hypothesis discusses the AHA recommendations for antimicrobial prophylaxis for IE and indicates some inherent limitations associated with it, stressing upon the fact that these recommendation should also be updated, if not completely changed, to cope up with the advancements in the proper treatment plan.

The intention of these recommendations is laudable. Of course, there will continue to be controversies with the new rules. Nevertheless, we believe they should be followed until there is more persuasive evidence to the contrary.

References

1Kim A, Keys T. Infective endocarditis prophylaxis before dental procedures: new guidelines spark controversy. Cleve Clin J Med 2008;75:89-92.
2Malinverni R, Overholser CD, Bille J, Glauser MP. Antibiotic prophylaxis of experimental endocarditis after dental extractions. Circulation 1988;77:182-7.
3Lockhart PB, Brennan MT, Sasser HC, Fox PC, Paster BJ, Bahrani-Mougeot FK. Bacteremia associated with toothbrushing and dental extraction. Circulation 2008;117:3118-25.
4Que YA, Moreillon P. Infective endocarditis. Nat Rev Cardiol 2011;8:322-36.
5Poveda-Roda R, Jiménez Y, Carbonell E, Gavaldá C, Margaix-Muñoz M, Sarrión Pérez G. Bacteremia originating in the oral cavity. A review. Med Oral Patol Oral Cir Bucal 2008;13:E355-62.
6Carmona IT, Dios PD, Scully C. An update on the controversies in bacterial endocarditis of oral origin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93:660-70.