Dental infections, part 2 — prophylaxis: help avoid antimicrobial resistance

Wiyanna K. Bruck, PharmD, and Jessica Price continue their discussion of concepts surrounding antibiotic prophylaxis in dentistry

Introduction

Use of antimicrobials in the field of dentistry is not limited to treating active dental infections. Many dentists prescribe antibiotics as a onetime dose prior to performing procedures. In fact, in the United States, general and specialty dentists are the third-highest prescribers of antibiotics in all outpatient settings.¹ Moreover, looking at data from 2017 to 2019, it is estimated that somewhere between 30% to 85% of dental antibiotic prescriptions are “suboptimal or not indicated.”^2-4 Appropriate use of antibiotics for prevention of infections surrounding dental procedures has received a lot of attention recently, which was illustrated by the American Dental Association (ADA) updating its antibiotic stewardship recommendations in the fall of 2020.⁵ It is well-known that antibiotics are one of the greatest medical advances that laid a foundation for an area of medicine, which has allowed once deadly infections to be readily treatable.⁶  However, excessive antibiotic use, even if it is just one dose, comes with consequences of side effects, antibiotic resistance, and superinfections like Clostridioides difficile.

Being attentive to appropriate antimicrobial prescribing is vital in all fields of healthcare, including dentistry, which is not limited to treatment, but also applies to antimicrobial prophylaxis.^7,8 To aid in considering the threats of overusing antibiotics, but also being able to recognize when antibiotics are warranted, the Centers for Disease Control and Prevention (CDC) has constructed a Checklist for Antibiotic Prescribing in Dentistry (see Table 1). This checklist serves as an excellent supplement to concepts surrounding antibiotic prophylaxis in dentistry that will be discussed in further detail.⁹

Prevention of transient bacteremia from dental procedures

There are antibiotic prophylaxis recommendations for two types of patients undergoing invasive dental procedures, which include those with heart conditions who may be at an increased risk of infective endocarditis and those with prosthetic joint(s) who may be predisposed to the development of a hematogenous infection at the site of the prosthetic(s). The oral cavity is colonized with numerous microorganisms that comprise between 300 to 600 species of bacteria, fungi, and protozoa. The rationale for antibiotic prophylaxis is to reduce or eliminate transient or intermittent bacteremia (bacteria in the bloodstream) caused by invasive dental procedures that might result in more severe infections for these high-risk patients.¹⁰ Theoretically, patients with certain conditions and/or a compromised immune system might not be able to mount an immune response adequate to clear intermittent bacteremia originating from their oral flora. However, the exact risk is unknown as transient bacteremia from everyday activities (e.g., brushing teeth, chewing) might pose a higher risk for closed-spaced infections in these populations than transient bacteremia after a dental procedure in a patient without an active dental infection.^11,13

Antibiotic prophylaxis: infective endocarditis

In 2008, the American Heart Association (AHA) published guidelines related to the prevention of infective endocarditis, which included guidance from the American Dental Association (ADA).¹³ The first iteration of the guidelines were supplemented with an updated scientific statement by the AHA in 2021.^14,15 The scientific statement reaffirmed previous recommendations that prophylaxis is warranted in only a small subset of patients at highest risk of adverse outcomes. The recommendations consider the available evidence, weighing the benefits of preventing infective endocarditis with the risks, which include undue adverse effects as well as contribution to antimicrobial resistance. Moreover, these recommendations only apply to invasive dental procedures in which there is manipulation of the gingival tissue or periapical region of teeth, or perforation of the oral mucosa.^16-18 The four broad categories of underlying conditions for which antimicrobial prophylaxis is advised are summarized in Table 2. The antibiotics suggested for use in those who are deemed to be at highest risk have empiric activity against the most common oral bacterial pathogens, most notably viridans group streptococci. The antibiotic regimen is chosen based on patients’ age, history of antibiotic allergy, and whether they can take oral medications (see Table 3). The antibiotic is given as a onetime by mouth dose 30 to 60 minutes prior to the invasive dental procedure; hence, prior to the dental appointment, patients would need to have a prescription written with enough time to have it filled and administered. If the prescription is inadvertently not taken by patients before the procedure, then it can be given up to 2 hours after the procedure.¹⁹

One notable change in the 2021 AHA recommendations is that clindamycin has been removed from the options for prophylaxis because it may cause more frequent and severe reactions than other antibiotics used for prophylaxis.¹⁹ Clindamycin used to be the recommended prophylactic agent for patients with severe penicillin allergies. However, clindamycin has a listed a black box warning for Clostridioides difficile infection (CDI), which can be seen with onetime doses. The Minnesota Health Department found that patients were significantly more likely to have received a prescription for clindamycin in comparison to patients who received prescriptions from other non-dental providers. In this same study between the years of 2009 to 2015, it was found that 15% of patients with community-acquired CDI were treated by their dentist showing that a onetime prescription can produce undue downstream effects.²⁰ The suggested alternatives for individuals unable to tolerate penicillin and β-lactam agents are azithromycin, clarithromycin, or doxycycline. If a patient has a non-IgE mediated allergy to penicillin or ampicillin, first- or second-generation cephalosporins can be chosen.¹⁹

Antibiotic prophylaxis: prosthetic joint Infections

In contrast with antibiotic prophylaxis to prevent infective endocarditis, the ADA Council on Scientific Affairs concluded that “Evidence fails to demonstrate an association between dental procedures and prosthetic joint infections or any effectiveness for antibiotic prophylaxis.” Given this information in conjunction with the potential harm from antibiotic use, using antibiotics before dental procedures is not recommended to prevent prosthetic joint infections. Additional case control studies are needed to increase the level of certainty in the evidence to a level higher than moderate.²¹ Due to the paucity of available literature in this area, there may be individual scenarios when it is not apparent if antibiotic prophylaxis is indicated. In these cases, all patients, their risk of invasive infection due to oral pathogens after a dental procedure, as well as the risks and the benefits of antibiotic prophylaxis should be carefully weighed.^21-26 However, the ADA guidelines cite that in cases where antibiotics are deemed necessary, it is most appropriate that the orthopedic surgeon recommend the appropriate antibiotic regimen and, when reasonable, write the prescription.

Pediatric considerations in antimicrobial prophylaxis

Pediatric dosing considerations for antimicrobial prophylaxis are also found in the AHA guidelines as seen in Table 3. Recommendations for pediatric patients are similar to adults with respect to empiric pathogen coverage, type of dental procedure warranting prophylaxis, and the use of a single oral prophylactic antibiotic dose. Clinicians should ensure the pediatric weight-based dose does not exceed a single adult dose.²⁶ Pediatric patients are approached with less concrete guidance than adult patients, which has been described in separate documents. More discussion regarding pediatric patients with a compromised immune system who may be at an increased risk of complications of bacteremia are discussed in the Reference Manual of Pediatric Dentistry.^16,27 In the Best Practice Report provided by the ADA Council on Scientific Affairs, it is mentioned that there is a lack of data to fully support antimicrobial prophylaxis as well which high-risk patients should be considered for antimicrobial prophylaxis. Several additional conditions could also warrant prophylaxis for pediatric patients, including the following:

• immunosuppression secondary to human immuno-deficiency virus (HIV)
• severe combined immunodeficiency (SCIDS)
• neutropenia
• cancer chemotherapy
• stem cell or solid organ transplantation
• history of head and neck radiotherapy
• autoimmune disease
• sickle cell anemia or other asplenia
• chronic high dose steroid use
• uncontrolled diabetes
• bisphosphonate therapy
• hemodialysis²⁷

Additionally, if a patient undergoing an invasive dental procedure has a vascular shunt, a consultation with the child’s physician is warranted to guide the need for and selection of antibiotic prophylaxis.

Summary

It is not only imperative to be cautious with antibiotic overprescribing for the intended treatment of dental infections, but also equally important that careful consideration is taken prior to prescribing antibiotics for dental infection prophylaxis. Although prophylaxis is generally a onetime dose of antibiotics, there is still the potential for negative downstream effects of antimicrobial resistance and/or undue side effects. Table 1 provides a summary of tools that can be utilized to assist dental practitioners in curbing antimicrobial threats surrounding dental prophylaxis as well as dental infection treatment.