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A Clinician’s Guide to Clinical Endodontics

Course Number: 562

Pain Medication and Antibiotics

The most consistent predictive factor for postoperative endodontic pain is the presence of preoperative hyperalgesia (spontaneous pain, reduced pain threshold, and/or increased perception of noxious stimuli).48 A clinical study by Ali et al49 showed that postoperative pain was present in 54.5% of patients treated. A common clinical mistake in endodontic-treatment pain management is prescribing drugs after treatment without critically assessing whether the drugs are pharmacologically treating inflammation and/or infection. An example would be prescribing antibiotics for tooth pain that has an inflammatory rather than an infection etiology. Fouad50 reported that antibiotics do not have an analgesic effect on odontogenic inflammatory pain. The pretreatment endodontic and periradicular diagnosis is a clinical guide for determining inflammation and/or infection. If the treatment diagnosis is irreversible pulpitis with or without symptomatic apical periodontitis, the condition is strictly inflammation, and anti-inflammatory drugs (NSAIDs) are the medication of choice.

Significant reduction in odontogenic pain from inflammation can be seen from 400 mg to 800 mg of ibuprofen.51 A recent study by Taggar et al52 reported that ibuprofen sodium dihydrate provided faster pain relief than ibuprofen acid. In cases when ibuprofen alone is not effective in reducing postoperative pain for an endodontic patient, administering a combination of ibuprofen and acetaminophen can produce significantly effective pain management for odontogenic-type inflammation.53 Acetaminophen, alone or in combination with an opioid (eg, hydrocodone), is a good alternative analgesic for a patient who cannot take NSAID medication.35

There will be cases in which NSAIDs do not relieve a patient’s odontogenic postoperative pain. Although opiate medications are commonly prescribed in these scenarios, a dentist also should consider prescribing dexamethasone, a synthetic adrenocortical steroid.54

If there is an odontogenic infection, a patient should additionally be placed on an antibiotic because steroids can block or mask the body’s response to infection. When dexamethasone is prescribed, the patient should stop taking NSAIDs if they are currently being taken for pain because they can lead to an increased risk of developing stomach problems, such as a bleeding stomach ulcer.

The current trend in prescribing antibiotics in endodontic treatment is as adjunctive treatment to conventional or surgical endodontic treatment. Adjunctive antibiotic treatment may be necessary for preventing the spread of infection, in acute apical abscesses with systemic involvement, and for progressive and persistent infections.55 Systemic involvement in clinical infection can appear as fever, swelling, malaise, a compromised airway, or cellulitis, as well as in a medically compromised patient.

Penicillin V potassium (pen VK) has been documented in the scientific literature as the antibiotic of choice for endodontic infections.56 It has been demonstrated that the pen VK spectrum of antimicrobial activity includes many of the bacteria that have been isolated in endodontic infections.57 Segura-Egea et al55 reported that amoxicillin or amoxicillin with clavulanic acid showed a better absorption, higher blood levels, better tissue penetration, and fewer adverse side effects than pen VK. Amoxicillin and amoxicillin with clavulanic acid have a wider spectrum of activity than pen VK.58 This spectrum includes many species of bacteria found elsewhere in the body and may increase the risk of selecting bacteria resistant outside the oral cavity. However, amoxicillin and amoxicillin with clavulanic acid are indicated for the treatment of immunocompromised patients who may have odontogenic infections containing non-oral bacteria.57 

For the patient allergic to penicillin/amoxicillin or if penicillin/amoxicillin has been ineffective, clindamycin is the second antibiotic of choice. Clindamycin is beta-lactamase resistant (unlike pen VK) and has a good spectrum against gram-positive and gram-negative bacteria.58 Another option if pen VK is ineffective is to add metronidazole along with the pen VK. Metronidazole should not be given as the sole antibiotic, but rather in combination with pen VK. Metronidazole has a narrow therapeutic spectrum against obligate anaerobic bacteria.59

When prescribing antibiotics, it is important to use a loading dose. Antibiotics with long half-lives can require several days of therapy to achieve effectiveness. In addition, the most critical time for antibiotic effectiveness is the first 24 hours, which is typically when inoculum of infection is high and likely to harbor resistant subpopulations of bacteria.60,61

Scientific literature has stated that clinicians prescribe antibiotics in courses of 3 to 7 days.62 Some evidence suggests that perhaps shorter courses (2 to 3 days) of antibiotic therapies may be as successful.63 The use of amoxicillin for 7 days has been shown to increase the population of resistant strains of bacteria.64 In addition, the dentist should be in close contact with the patient who is taking antibiotics in the event that clinical symptoms worsen or there is a drug allergy.65 Finally, if an endodontic patient presents with an intraoral fluctuant swelling, the clinician should perform an incision-and-drain procedure.66