Background-Antibiotic prophylaxis recommendations for the prevention of infective endocarditis are based in part on studies of bacteremia from dental procedures, but toothbrushing may pose a greater threat. The purpose of this study was to compare the incidence, duration, nature, and magnitude of endocarditis-related bacteremia from single-tooth extraction and toothbrushing and to determine the impact of amoxicillin prophylaxis on single-tooth extraction. Methods and Results-In this double-blind, placebo-controlled study, 290 subjects were randomized to (1) toothbrushing, (2) single-tooth extraction with amoxicillin prophylaxis, or (3) single-tooth extraction with identical placebo. Blood was drawn for bacterial culturing and identification at 6 time points before, during, and after these interventions. The focus of our analysis was on bacterial species reported to cause infective endocarditis. We identified 98 bacterial species, 32 of which are reported to cause endocarditis. Cumulative incidence of endocarditis-related bacteria from all 6 blood draws was 23%, 33%, and 60% for the toothbrushing, extraction-amoxicillin, and extraction-placebo groups, respectively (PϽ0.0001). Significant differences were identified among the 3 groups at draws 2, 3,4, and 5 (all PϽ0.05). Amoxicillin resulted in a significant decrease in positive cultures (PϽ0.0001). Conclusions-Although amoxicillin has a significant impact on bacteremia resulting from a single-tooth extraction, given the greater frequency for oral hygiene, toothbrushing may be a greater threat for individuals at risk for infective endocarditis. (Circulation. 2008;117:3118-3125.)

Background Infective endocarditis (IE) often is caused by bacteria that colonize teeth. The authors conducted a study to determine if poor oral hygiene or dental disease are risk factors for developing bacteremia after toothbrushing or single-tooth extraction. Methods One hundred ninety-four participants in a study were in either a toothbrushing group or a single-tooth extraction with placebo group. The authors assessed the participants’ oral hygiene, gingivitis and periodontitis statuses. They assayed blood samples obtained before, during and after the toothbrushing or extraction interventions for IE-associated bacteria. Results The authors found that oral hygiene and gingival disease indexes were associated significantly with IE-related bacteremia after toothbrushing. Participants with mean plaque and calculus scores of 2 or greater were at a 3.78- and 4.43-fold increased risk of developing bacteremia, respectively. The presence of generalized bleeding after toothbrushing was associated with an almost eightfold increase in risk of developing bacteremia. There was no significant association between any of the measures of periodontal disease and the incidence of bacteremia after toothbrushing. The oral hygiene or disease status of a tooth was not significantly associated with bacteremia after its extraction. Conclusion Bacteremia after toothbrushing is associated with poor oral hygiene and gingival bleeding after toothbrushing. Clinical Implications Improvements in oral hygiene may reduce the risk of developing IE.

The role of fluorodeoxyglucose F 18 PET in the detection of RCC is limited by low sensitivity. With superior specificity PET may have a complementary role as a problem solving tool in cases that are equivocal on conventional imaging.

Predicting student performance in the classroom is an important area of educational research owing to its potential for helping educators identify students who may have difficulty grasping the material in a course. The goal of this research was to develop a sensitive and specific pre-semester assessment for students enrolled in general chemistry for science majors that would identify students at risk for failing the course. The student pre-semester assessment (SPSA) predicted 40.8% of the students who went on to fail first-semester general chemistry. It was a better predictor of at-risk students than the Toledo exam (27.7%), SAT (16.8%), or predicted grade point index (PGI) (29.4%). The inclusion of demographic variables did little to increase the SPSA's predictive power, but math and chemistry background and age significantly increased the accuracy of predicting at-risk students when combined with either the SAT score or the PGI.