Capability of Senior Dental Students in Detecting the Presence and Diagnosing the Depth of Proximal Caries on a Bitewing Radiograph

Accurate and early detection of a carious lesioncan prevent its further extension. Therefore, capability to accurately diagnose carious lesions is a must-have qualification for dental graduates. The purpose of this study was to evaluate the ability of senior dental students of a dental university in detecting the presence and diagnosing the depth of proximal caries on a bitewing radiograph.

The present study was a diagnostic assessment and a total of 100 bitewing radiographs of optimal quality were randomly selected from patients’ files. Radiographs were separately observed by 30 senior dental students and 5 university professors from Shahid Beheshti School of Dentistry (in order to determine the gold standard) under similar conditions. The observers were asked to detect presence of carious lesions and diagnose its depth according to the set criteria and mark in the questionnaire. If 3 university professors unanimously agreed on presence or absence of caries, this opinion would be chosen as the gold standard of the study. In order to obtain reliability, radiographs were once again observed and evaluated one month later by the same 5 university professors and 11 students. Data were analyzed using SPSS software and Kappa values were analyzed and compared with t-test.

The mean Kappa value for 2 times observation was 0.777±0.065 among professors and 0.664±0.131 among students. According to Fleiss, this rate was excellent for 3 professors and 3 students. Diagnostic sensitivity, specificity, positive predictive value and negative predictive value of students in caries detection were 78.22%, 82.14%, 79.68% and 80.81%, respectively.

Diagnostic capability of students in differentiating carious lesions from healthy tissue was optimal and their reliability was not significantly different from the gold standard. Students were mostly able to detect the presence of carious lesions but there was an under-estimation about the depth of caries.