Antibiotic use in dentistry of bacteria from advanced caries. The first line of treatment is the removal of the source of inflammation or infection by local operative measures. Generally, the abscess can be eradicated through surgical drainage alone; however this is sometimes inadequate. Therefore, systemic antibiotic treatment may be required, but only if there is evidence of spreading infection. As the bacteria involved are known, antibiotic therapy selection can be specific, based on published susceptibilities. Penicillin in the form of amoxicillin is the most common antibiotic to use. However, 3% of the patient population is allergic to penicillin, so erythromycin is often used in
Antibiotic levels in the blood. Women with menstrual irregularities may be at higher risk of failure and should be advised to use backup contraception during antibiotic treatment and for one week after its completion. If patient-specific risk factors for reduced oral contraceptive efficacy are suspected, backup contraception is recommended. In cases where antibiotics have been suggested to affect the efficiency of birth control pills, such as for the broad-spectrum antibiotic rifampicin, these cases may be due to an increase in the activities of hepatic liver enzymes' causing increased breakdown of the pill's active ingredients. Effects on the intestinal flora, which might