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
Β-lactam antibiotic lower "c" values (better binding to PBPs). By definition, all β-lactam antibiotics have a β-lactam ring in their structure. The effectiveness of these antibiotics relies on their ability to reach the PBP intact and their ability to bind to the PBP. Hence, there are two main modes of bacterial resistance to β-lactams: If the bacterium produces the enzyme β-lactamase or the enzyme penicillinase, the enzyme will hydrolyse the β-lactam ring of the antibiotic, rendering the antibiotic ineffective. (An example of such an enzyme is New Delhi metallo-beta-lactamase 1, discovered in 2009.) The genes encoding these enzymes may be inherently present