Inside Dentistry
January 2008
Volume 4, Issue 1

Question: Is antibiotic therapy indicated for necrotic teeth?

Ken Koch, DMD; Gregori M. Kurtzman, DDS; Michael Siegel, DDS, MS

Dr. Koch

This question remains a bit controversial in endodontics but let me share the opinion of the American Association of Endodontists as stated in their publication “Antibiotics and the Treatment of Endodontic Infections.”1 

The key issue in differentiating between the use and non-use of antibiotics in necrotic teeth is whether the patient has systemic signs and symptoms associated with a severe endodontic infection. Some of these symptoms would be: a fever higher than 100º F, lymphadenopathy, increased swelling or cellulitis, trismus, osteomyelitis, or a persistent infection. These patients should receive a course of adjunctive antibiotics.

Conditions not requiring adjunctive antibiotics (according to the AAE) would be: pain without signs and symptoms of infection, asymptomatic teeth with necrotic pulp and radiolucency, teeth with a sinus tract, and a small localized swelling without systemic signs and symptoms of infection or spread of infection.

When using antibiotics, the drug of choice for periradicular abscesses remains penicillin VK. A loading dose of 1,000 mg should be orally administered, followed by 500 mg every 4 to 6 hours for 5 to 7 days. However, about 10% of the population will report an allergy to penicillin. In these cases, clindamycin is a good choice; it is also a good choice when a change in antibiotics is indicated. Both penicillin and clindamycin have been shown to produce good results in treating odontogenic infections. According to the AAE, the oral adult dose of clindamycin for serious endodontic infections is a 600-mg loading dose followed by 300 mg every 6 hours for 5 to 7 days.

Clinicians must understand that endodontic infections are polymicrobial in nature and the prescribing of antibiotics should be considered adjunctive to the clinical treatment of the patient; antibiotics should not be substituted for proper root canal debridement and drainage of purulence from a periradicular swelling (when indicated). The pulp status of a tooth does not indicate, by itself, the use of antibiotics.

Dr. Kurtzman

Antibiotics are indicated to assist the body in eliminating infection that the immune system is unable to cope with on its own. Endodontic treatment helps to reduce the bacteria and the cause of the infection within the tooth that is feeding the periapical lesion to allow the body to eliminate any infection outside the canal system. With regard to necrotic teeth, in the absence of: periapical lesions that are larger than apical PDL widening; swelling; significant exudate within the canal; or continuing pain after debridement of the canal system, antibiotic administration does not serve a true benefit to the patient. Because antibiotics are carried by the circulatory system to the areas of infection and a necrotic pulp is no longer connected to the circulatory system, orally administered antibiotics serve no benefit within the tooth. Their benefit is in helping the body reduce bacteria in periapical lesions that the patient’s immune system alone cannot manage. Unfortunately, the over-prescribing of oral antibiotics has led to antibiotic-resistant strains of bacteria and has made treatment when an antibiotic is required more difficult. The body is capable of dealing with minor infections and antibiotic use with regard to necrotic teeth should be reserved for cases when swelling is noted, significant exudate is present in the canal system, or when symptomatology is worsening despite endodontic intervention.

Dr. Siegel

As a general rule, the answer to this question is “absolutely not” as there is no indication to do so. The majority of necrotic teeth drain through the canal or a sinus tract and are, therefore, draining outside the body. Moreover, up to 10% of Americans who have been tested are allergic to the “cillin” antibiotics and unwarranted prescription is more likely to lead to an allergic reaction than to prevent an acute infection in a chronically infected site.

Indications for antibiotic coverage for patients with necrotic teeth might include:
1. Signs of active infection to include swelling, fever, purulence, edema, and difficulty breathing and/or swallowing.
2. Patients who are immunocompromised at the time of extraction of the affected teeth, including:

• Poorly controlled diabetic patients who have an HbA1c above 7, a random blood sugar above 126 mg/dL, or who do not take their medication. Because these patients would be expected to have poor wound healing, antibiotics would be indicated at the time of extraction.
• Patients with HIV/AIDS with a neutrophil count below 500 neutrophils per mm3 and/or a CD4 count below 200.
• Patients on chemotherapy known to cause neutropenia, such as Leukeran® (chlorambucil).

3. Patients who will need extractions of the necrotic teeth and need antibiotics for other reasons, such as prosthetic heart valves or total prosthetic joint replacement (hips, knees).


1. Antibiotics and the treatment of endodontic infections. American Association of Endodontists. Colleagues for Excellence Newsletter. Summer 2006. Available at: www.aae.org. Accessed November 12, 2007.

Ken Koch, DMD
Real World Endo
Wilmington, Delaware
Gregori M. Kurtzman, DDS
Private Practice
Silver Spring,Maryland
Michael Siegel, DDS, MS
Professor and Chair
Department of Diagnostic Sciences
Nova Southeastern University
College of Dental Medicine
Fort Lauderdale, Florida

© 2021 AEGIS Communications | Privacy Policy