Background The aim of the present study was to investigate the impact of metal artifact reduction (MAR) algorithm of cone‐beam computed tomography (CBCT) on the diagnostic accuracy of fenestration and dehiscence around dental implants. Methods Twenty‐three dental implants were placed adjacent to the dehiscence and 23 adjacent to the fenestration defects on bovine bone blocks. The blocks were scanned with CBCT unit in two modes, with and without MAR algorithm. The area under the receiver operator characteristic (ROC) curves (Az value), specificity, sensitivity, positive predictive value, negative predictive value, and accuracy were determined for all modes. Results For both defects, the Az values were higher in off MAR condition. The values of sensitivity, positive predictive value, negative predictive value, and accuracy, were higher in off MAR condition for both defects. However, the specificity in both defects in the two modes was equal. Conclusion The MAR algorithm in CBCT unit may not be helpful in increasing the diagnostic accuracy of fenestration and dehiscence around dental implants.

Objectives: Many studies have verified the adverse effects of prolonged emergency department (ED) length of stay (LOS) on outcomes. Patient, physician, hospital, and system factors affect ED LOS. We investigate racial disparities in prolonged ED LOS for admitted patients, controlling for both patients' medical condition and hospital factors that could be responsible for potential disparities. Methods: We studied 6932 hospital admissions from 994 EDs in the National Hospital Ambulatory Medical Care Survey from 2009-2011. The main outcome was prolonged ED LOS, which was defined as triage to transfer to inpatient bed >6 hours. We use the logit model as the maximum likelihood model of choice. Akaike information criterion, Bayesian information criterion as well as the Pregibon's link test are used to test different specifications of the model. Results: The mean age of our sample was 57 years; 65% of patients were white, and 54% of them were female. A total of 58.5% of patients experienced prolonged LOS. Overall, 55.4% of whites stayed for more than six hours in the ED, compared to 64.1% of non-whites (p<0.01). Among the sample of this study, the average predicted probability of prolonged ED OLS was 0.5798, 0.5791, and 0.5989 in 2009, 2010, and 2011 respectively (p<0.01 for each year). On average, compared to white patients, black patients had a 7.3, 1.3, and 6.7 percentage point higher probability of having prolonged ED LOS, controlling for all other variables in 2009, 2010, and 2011 respectively (p<0.01). Conclusions: Non-white patients who are admitted to the main hospital through the ED have a longer ED LOS compared to whites, demonstrating that racial disparities still exist across U.S. hospitals.