Antibiotics for surgical prophylaxis
- R.G. Woods
- Aust Prescr 2005;28:41
- 1 April 2005
- DOI: 10.18773/austprescr.2005.031
The principles set out in the article can readily be applied to oral surgery. Most oral surgery is approached intra-orally although some, for instance open reduction of certain mandibular fractures, is approached externally. In general dental practice, the most common oral surgical procedure requiring an incision would be the removal of unerupted mandibular or maxillary third molars. Removal of these molars often requires removal of bone.
Many unerupted or partly erupted third molars develop a communication with the mouth, and the adjacent tissues are susceptible to infection, often with an anaerobic organism. Anaerobic streptococci and bacteroides are commonly associated with these infections.
Even if the infection associated with erupting or partly erupting third molars has been treated with an antibiotic it is likely that, even in the absence of major symptoms of infection, bacterial contamination will persist. In these circumstances the surgical procedure of third molar removal may be classified 'contaminated' using the criteria of Table 1 of the article.
Appropriate antibiotics for dental surgical prophylaxis include oral or intravenous amoxycillin or intravenous ampicillin or, if there is a history of penicillin allergy, oral cephalexin (if penicillin allergy is mild), oral or intravenous clindamycin or intravenous lincomycin. If oral antibiotics are used, they must be given at least one hour before the procedure to ensure adequate tissue concentrations at the time of the procedure. Intravenous prophylaxis is effective as soon as antibiotic administration is complete. Intravenous administration of some antibiotics, such as lincomycin or clindamycin, should be by slow infusion.1 Whether the antibiotic should be continued following third molar surgery where there has been a history of infection, is a matter of clinical judgement.
Although less frequent, surgery for removal of chronic granulomatous infections in maxillary or mandibular bone is also common. These infections which usually involve bone loss and sometimes development of a cyst are usually associated with infected or non-vital pulp tissue. The surgical procedure would be classified 'contaminated'. The organisms associated with an infection of this sort are not likely to be anaerobic unless they are associated with necrotic tissue, for instance a non-vital dental pulp. The antibiotics recommended for infected third molar surgery would be appropriate where an anaerobic infection is suspected. When there has been no necrotic tissue associated with the development of infection, amoxycillin, or in the penicillin-allergic patient, cephalexin (if penicillin allergy is mild), or clindamycin would be appropriate antibiotics.1
Associate Professor, Australian Dental Association