Mechanical defects in dental enamel vs. natural dental caries: observer differentiation using Ektaspeed Plus film.

The value of imaging modalities in enabling the observer to detect proximal dental caries has been tested previously using both natural carious cavitations and mechanical defects. This study compared the ability of dentists to detect mechanically created defects and natural dental carious cavitations on the proximal surfaces of extracted teeth, and to differentiate between the two. Detection rates according to lesion depth were also investigated. There was a difference in the ability of readers to detect natural proximal dental carious cavities and mechanical defects in the proximal enamel. The odds of detecting artificial cavities was 2.92 times the odds of diagnosing natural caries cavitations. There was great variation in the ability of the dentists to identify natural and artificial lesions. According to logistic regression, when the cavity depths are equal, the mechanical defects in the proximal dental enamel are easier to identify than are natural enamel dental caries cavitations. The odds ratio charts provided from this study show the depths of mechanical and natural lesions that are comparable in diagnostic challenge. These charts might permit rough approximations to be made when comparing previously published papers that variously use both mechanical defects and natural caries. Use of poorly designed in vitro models for testing can produce a false guide to the clinical performance of diagnostic systems.