- Antibiotics are used in dentistry for three main purposes: as adjuncts to treat oral infections, to prevent local infections from dental procedures, and to prevent oral bacteria from spreading to susceptible sites. - For high and moderate risk patients, antibiotics are recommended before certain invasive procedures like extractions but not for other procedures like fillings. - Common antibiotics used include penicillin, amoxicillin, and clindamycin which are effective against the streptococcus and anaerobic bacteria usually causing dental infections. Selection depends on factors like allergies and whether only anaerobic infections are suspected.