"Incidence of Post-Operative Infection after Oral Osseous Surgery". Diabetes mellitus is an increasingly common disease, and is often encountered in dental practice. Although it is a significant risk factor for post-operative infections after thoracic surgery, it is not known whether diabetes also confers risk for infection after oral surgery. Unique features of the oral environment prevent generalizing the thoracic surgical experience to oral surgery. In addition, the rate of infection in general dental patients, regardless of diabetes, is not well-defined but may be as low as 3%; the rate in diabetes patients undergoing oral surgery has not been reported. Despite the lack of evidence, a common current dental practice is to administer prophylactic antibiotics to diabetic patients undergoing invasive oral surgical procedures. With the rise of antibiotic resistance, any use of antibiotics should be justifiable with rigorous evidence, including this practice. We propose to conduct a prospective cohort study of 4100 patients presenting for periodontal osseous surgery, or surgical extractions to carry out the following Specific Aims:

1. Among all patients presenting for dental osseous surgery, to examine the incidence of post-operative infection and its risk factors; specifically, to test the hypothesis (H1) that diabetes is an independent risk factor for post-operative infection. 2. Among the estimated 1050 diabetes patients in this cohort, to test the following hypotheses: H2: Glycemic control and diabetes complications are independent risk factors for post-operative infection. H3: Administration of prophylactic antibiotics will be associated with lower risk for infection.

Consecutive patients scheduled for either of the two types of surgical procedures in a DPBRN general or specialty practice will be eligible to enroll in this study. Patients will provide demographic and medical information and dentists will record the type, duration, and complexity of the procedure on standardized forms. The dental staff will also assess finger stick glucose level using a glucose home monitoring device, and obtain finger stick blood for HbA1c before the procedure. The DPBRN Regional Coordinator will contact participants at 7 and 20 days after the procedure and administer a standardized short questionnaire screening for symptoms of infection and side effects of antibiotics, if given. Patients reporting any symptoms will be re-examined and presence or absence of infection will be confirmed. We will use multi-variable analysis, accounting for clustering by practice, to analyze the results of the study. We will have 80% power to detect differences infection rates as low as 3% in normal individuals and 5% among diabetes patients. This study will contribute missing evidence to inform guidelines for antibiotic prophylaxis in oral surgical patients, and form the basis for a future trial testing strategies to reduce infectious risks.