Concurrent Validity of an Epidemiological Diagnostic System for Caries with the Histological Appearance of Extracted Teeth as Validating Criterion

Abstract

The ability of an epidemiological diagnostic system to distinguish tooth sites with carious cavities from those without was investigated. The diagnostic data were obtained during annual clinical and bitewing radiographical examinations of 551 teenage clinical trial subjects. 109 premolars and permanent molars, extracted during subsequent treatment of the subjects, were kept. Undecalcified serial sections of these teeth were examined in water at × 2.5 magnification under incident light, to compare the original diagnostic findings with the histological extent of caries. Quantitative methods were used to estimate the concurrent validity of clinical diagnosis of pits and fissures and the radiological diagnosis of posterior approximal surfaces. For fissure diagnosis a validity coefficient (r_t) of 0.83 was obtained. 84% of cavities were detected while 22% of sites without cavitation were wrongly diagnosed as having cavities. For radiological diagnosis the validity coefficient (r_t) was 0.95. Although 97% of surfaces without cavitation were correctly identified, only 73% of approximal cavities were detected radiologically. The effect of different factors on the validity findings is considered.