Interpretation of bitewing radiographs. Part 2. Evaluation of the size of approximal lesions and need for treatment.

OBJECTIVE: The decision to treat initial approximal carious lesions is based mainly on interpretation of bitewing radiographs. In a previous report, it was shown that artificial approximal lesions of uniform size are more readily detected on radiographs in premolars than in molars. The objective of the present study was to compare the ability to evaluate the depth of similar size artificial lesions on radiographs and reach decisions concerning treatment, in premolars and molars.

METHOD: Clinicians were asked to evaluate on radiographs, the size of in vitro prepared artificial lesions, and decide at which point they would perform a restoration.

RESULTS: Significant differences were found in the evaluation of lesion depth between different tooth surfaces. The interaction between lesion depth and tooth surface originated from the examiners' trend to score same size lesions as penetrating deeper into the tooth in premolars than in molars. The probability of the examiners to decide on restorative treatment in shallow lesions (0.25 mm, 0.50 mm) was higher in premolars than in molars.

CONCLUSIONS: The findings suggest that clinicians evaluate initial lesions as being deeper and more prone to treatment in premolars than in molars.