Antibiotic Prophylaxis for Dental Procedures

In 2007, the American Heart Association (AHA) developed the current guidelines for antibiotic prophylaxis in the dental setting for patients with a high risk of developing IE. These guidelines provide evidence-based recommendations for the provision of antibiotic prophylaxis for patients with certain cardiac conditions that have been deemed to be of the highest risk, including those with a history of IE, prosthetic heart valves, a history of cardiac transplant with valvulopathy, and certain congenital heart conditions.⁵ The AHA has not found quality evidence to support antibiotic prophylaxis in the dental setting for patients with nonvalvular cardiac devices, such as indwelling vascular catheters or cardiovascular implantable electronic devices.⁶ Although the AHA and the American College of Cardiology have revised the aforementioned guidelines throughout the years,^7,8 the recommendations for dental settings have remained unchanged since 2007. In the most recent iteration,⁸ the authors explicitly stated that the level of evidence for these recommendations was relatively low but made no recommendations for change. The recommendations for dental settings and recommended prescribing regimens are summarized in Table 1 through Table 3.⁵

Historically, recommendations for antibiotic prophylaxis for high-risk patients undergoing dental procedures date back to the 1950s, when similar recommendations were made for patients undergoing gastrointestinal, genitourinary, and respiratory procedures. These early guidelines were not heavily evidence-based but, instead, relied on empirical data and expert opinion.⁹ The American Dental Association (ADA) first endorsed recommendations in 1972, which included pre- and postoperative antibiotic regimens as well as an explicit emphasis on maintaining good oral hygiene as a protective measure against IE.¹⁰ The broad scope of dental procedures for which prophylaxis was recommended included all that elicited bleeding. Beginning in 1977, newer guidance was released that stratified cardiac patients into different risk groups and identified particularly high-risk dental procedures.^5,11-14 The AHA guidelines that were issued in 1997 eliminated the use of postoperative antibiotics and introduced the use of a single preoperative dose, which is still recommended today. Importantly, clindamycin replaced erythromycin as the drug of choice for patients with penicillin allergies.
The 1997 guidelines also narrowed the scope of the procedures for which antibiotic prophylaxis was required and explicitly questioned the dental connection to IE, suggesting that "the vast majority of endocarditis due to oral organisms is not related to dental treatment procedures."

Guidelines aside, there has been and still is great conflict within the healthcare community about whether dental procedures cause IE, whether prophylaxis reduces bacteremia, and whether reduced bacteremia results in reduced IE.⁹ Variability exists within the literature regarding to what extent specific dental procedures contribute to bacteremia. Transient bacteremia has been measured following 10% to 100% of extractions, 8% to 80% of scaling and root planing procedures, up to 40% of hygiene prophylaxis procedures, 36% to 88% of periodontal surgeries, and as many as 20% of endodontic procedures.⁵ However, the annual cumulative exposure to bacteremia from everyday activities has been shown to be 5 to 6 million times greater than the exposure from the extraction of one tooth.⁹

Direct reports question dental treatment as a risk factor for developing IE.¹⁵ In a case-control study, Strom and colleagues found no relationship between dental treatment and IE.¹⁵ In addition, Pallasch estimated that fewer than 1 out of every 14 million visits to a dental office led to IE.¹⁶ The 2007 AHA guidelines suggested that focusing on the frequency of bacteremia in dental patients and the development of IE has yielded too great an emphasis on antibiotic prophylaxis and an insufficient emphasis on proper oral hygiene and access to regular prophylactic care, which, in all likelihood, are more effective means of mitigating the risk of IE.⁵ The lack of supporting evidence regarding antibiotic prophylaxis, as well as the inherent risks of antibiotics, led to changes in the 2007 guidelines, in which premedication is recommended only for cardiac patients with the highest risk of developing IE.⁸

The efficacy of antibiotic prophylaxis in reducing bacteremia in dentistry is also debated.⁵ Some studies have reported that prophylaxis reduced the duration, magnitude, and frequency of bacteremia after dental procedures,¹⁷ whereas others have found that prophylaxis had no effect on bacteremia.¹⁸ Using real-time quantitative polymerase chain reaction (qPCR), a 2016 study found that there was a low incidence of bacteremia after endodontic procedures and that, even when administered, antibiotic prophylaxis did not appear to affect the magnitude of bacteremia during or after such procedures.¹⁹ Furthermore, there is a surprising lack of evidence that antibiotic prophylaxis prevents IE resulting from dental procedures in high-risk patients.²⁰

The most updated guidelines regarding antibiotic prophylaxis for patients with prosthetic joints undergoing dental treatment were released in 2015 by the ADA's Council on Scientific Affairs in conjunction with the American Academy of Orthopaedic Surgeons. The recommendation is simple: antibiotic prophylaxis prior to dental procedures for these patients is generally not recommended to prevent infections of prosthetic joints, except for those who have experienced prior complications related to their joint replacement surgery.²¹ The decision to prescribe antibiotics prophylactically should be made by the patient and orthopedic surgeon after a thorough health history. For cases in which antibiotics are considered necessary, the guidelines recommend that the orthopedic surgeon should both determine the specific antibiotic regimen and provide the prescription.

The new recommendations are evidence-based and founded upon the notion that, for the majority of patients, the risks of antibiotic use outweigh any potential benefits.²¹ These risks include anaphylaxis,²² antibiotic resistance,²³ and opportunistic infections.²⁴ The guidelines state with "moderate certainty" that the evidence demonstrates no association between dental procedures and prosthetic joint infections.^21,25-28 Interestingly, microbes cultured from transient bacteremia that are presumed to be dental in origin (eg, viridans group streptococci, nonpathogenic gonococci, β-hemolytic streptococci, and gram-positive anaerobes) differ from those cultured from prosthetic joint infections (eg, staphylococci).²⁷ Furthermore, current evidence suggests that antibiotic prophylaxis does not prevent prosthetic joint infections in patients undergoing dental procedures and that older studies suggesting otherwise were of poor quality.²⁷ There are no data supporting premedication for partial joint replacements or other surgically implanted orthopedic hardware, including pins, plates, and screws.

Antibiotic premedication is utilized for patients who present for dental care with a myriad of conditions for which there is no routine guidance regarding their utility and use. Patients with compromised immune systems from certain conditions, such as human immunodeficiency virus (HIV), neutropenia, and solid organ transplantation with antirejection medication use, as well as those undergoing chemotherapy or dialysis or those with uncontrolled diabetes, might be advised to premedicate prior to dental procedures due to their excessive risk of postoperative infection. Whenever a question arises regarding the potential need for antibiotic premedication, consultation with medical providers is warranted.

Current guidelines have narrowed the field of clinical situations in which antibiotic prophylaxis is recommended. Only when the benefits outweigh the risks and its use is within the scope of existing guidelines should premedication be considered. The overuse of antibiotics puts individual patients and society as a whole at undue risk of developing sensitivities, resistance, and opportunistic infections. Providers should educate their patients and colleagues so that evidence-based choices regarding antibiotic prophylaxis can be made. 

Jonathan Shapiro, DMD
Private Practice
Manhattan Beach, California

Brooke Blicher, DMD
Upper Valley Endodontics
White River Junction, Vermont

Assistant Clinical Professor
Department of Endodontics
Tufts University
School of Dental Medicine
Boston, Massachusetts

Rebekah Lucier Pryles, DMD
Upper Valley Endodontics
White River Junction, Vermont

Assistant Clinical Professor
Department of Endodontics
Tufts University
School of Dental Medicine
Boston, Massachusetts