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Endodontics Supporting Your Practice

What is the best antibiotic for orofacial infections of an endodontic nature?

Spilled Pills

Infections of an endodontic nature that are associated with orofacial pain are typically caused by obligate anaerobic bacteria. Given the spectrum of action, penicillins are the preferred antibiotic of choice. Drugs in this class act against the obligate anaerobes but, also affects the substrate interrelationships amongst various bacterial strains within the infection. As some of the strains of bacteria start to die, the others are unable to survive. The penicillins include amoxicillin as well as Augmentin (an amoxicillin and clavulanate combination).

When penicillin is not effective, clindamycin may be used as it acts against anaerobic bacteria. However, clinician’s should use this antibiotic with caution as it has the potential to cause pseudomembranous colitis.

Metronidazole can also be considered alone or in combination with penicillin or amoxicillin. This drug targets gram-negative obligate anaerobes.

Source: Dental Secrets, Elsevier, 2015 


  1. Richard G Graves November 13, 2015

    It has been my understanding that PenV is the best oral antibiotic for infections of an endodontic nature. What is the antibiotic of choice if one is allergic to Penicillin ?

    1. Anonymous November 14, 2015


  2. Robert Kaufmann December 5, 2015

    Based on recent antibiotic susceptibility tests,
    penicillin VK is the drug of choice for periradicular
    abscesses .
    It is effective against facultative and anaerobic
    microorganisms associated with endodontic infections.
    Penicillin VK remains the antibiotic of choice because
    of its effectiveness, low toxicity and low cost. However,
    about 10 percent of the population will give a history
    of allergic reactions to penicillin. To achieve a
    steady serum level with penicillin VK, it should be
    administered every four to six hours . A loading
    dose of 1,000 mg of penicillin VK should be orally
    administered, followed by 500 mg every four to six
    hours for five to seven days. Following debridement of
    the root canal system and drainage of facial swellings,
    significant improvement of the infection should be seen
    within 48-72 hours.
    Amoxicillin is an analogue of penicillin that is rapidly
    absorbed and has a longer half-life. This is reflected in
    higher and more sustained serum levels than penicillin
    VK. Because of these traits, amoxicillin is often used
    for antibiotic prophylaxis of patients that are medically
    compromised . Amoxicillin may be used for
    serious odontogenic infections, however, its extended
    spectrum may select for additional resistant strains of
    bacteria. The usual oral dosage for amoxicillin is 1,000
    mg loading dose followed by 500 mg every eight hours
    for five to seven days.

    From https://www.aae.org/uploadedfiles/…/endodontics…/summer06ecfe.pdf
    and https://www.aae.org/…and…/endodontics…for…/ecfewinter12final.pdf


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