Antibiotic Agents

Antibiotics are drugs that are produced by microbes or by chemical methods to produce an antibacterial action. Antibiotics are the second most prescribed group of drugs in dentistry, after local anesthetics. The widespread use of antibiotics has resulted in common bacteria developing resistance to drugs that once controlled them. To reduce the resistance rate, health care providers must prescribe antibiotics judiciously. Antibiotics should be prescribed as soon as possible for optimal healing. If the infection does not respond to the initially prescribed drug, a culture from the infected site is indicated. The duration of drug therapy should extend at least 5 days past the point of substantial improvement or resolution of symptoms. The importance of completing a full course of antibiotic therapy must be emphasized to the patient. Should the antibiotic be discontinued prematurely, the surviving bacteria can restart an infection that may be resistant to the original antibiotic.

Situations that may necessitate the prescription of antibiotics are:

Oral Wound Management

Oral wounds are associated with an increased risk of bacterial contamination. Examples of oral wounds are soft tissue laceration, complicated tooth fracture (pulp exposure), severe tooth displacement (including avulsion), gingivectomy, and severe ulcerations. If the oral wound seems to have been contaminated by extraoral bacteria, antibiotics therapy should be considered.

Dental Infection

Bacteria can gain access to pulpal tissue through caries, exposed dentin tubules and defective restorations resulting in acute dental infection. Treatment of acute dental infection is accomplished by immediate dental treatment (pulpotomy, pulpectomy or extraction). Antibiotic therapy is usually not indicated if the infection is contained within the pulpal tissue or the immediately surrounding tissue and the patient does not exhibit systemic signs of infection (fever and facial swelling).

Patients presenting with facial swelling secondary to a dental infection receive dental treatment accompanied by antibiotic therapy. If the clinician is able to achieve adequate local anesthesia, the dentist may render immediate treatment followed by a regimen of antibiotics. If the infection is of such severity that achievement of adequate local anesthesia is questionable, then prescription of antibiotics for a period of 5‑10 days should be considered before rendering treatment. While oral antibiotics may be the simplest route of administration, in cases of severe infection hospitalization and intravenous administration may be necessary.

Pediatric Periodontal Diseases

Prolonged antibiotic therapy may be prescribed for the management of chronic periodontal disease, especially in patients with an immunodeficiency disease. In pediatric periodontal diseases (neutropenias, Papillon-Fevere syndrome, leukocyte adhesion deficiency) the immune system is unable to control the growth of periodontal microbes. As this is a chronic rather than an acute condition, effective drug selection may be accomplished by culture and susceptibility testing.

Viral Diseases

Antibiotics should not be prescribed for viral conditions (acute primary herpetic gingivostomatitis) unless there is strong evidence to suggest that a secondary infection exists.

Oral Contraceptive Use

It is not uncommon for oral contraceptives to be prescribed for adolescent females to prevent pregnancy. When antibiotics are prescribed in concurrence with oral contraceptives, the patient must be advised to use additional birth control techniques as antibiotics may render the oral contraceptive ineffective for at least 1 week beyond the last dose.

Antibiotics can be categorized by the bacteria they target. They are either narrow or wide spectrum. Narrow spectrum antibiotics are effective specifically against either gram-positive or gram-negative antibiotics. Broad spectrum antibiotics are effective against a wider range of bacteria. The efficacy of an antibiotic against a particular bacteria is determined by culturing the pathogen and testing its susceptibility to a particular antibiotic. Unfortunately, culturing and susceptibility testing may take 24 hours to several days resulting in a delay in initiation of antimicrobial therapy. Thus, until culturing and susceptibility results are available a best guess is made for determining the most effective antibiotic for a specific clinical situation.2