Methods: Sixty-two interproximal carious lesions (30 molars; 32 premolars) planned for restorative treatment were included in the study. Preoperative F-speed film (Insight™) bitewing radiographs were taken and the extension of caries was scored independently by two experienced clinicians using an 8-point lesion severity scale, resulting in two sets of radiographic scores; an aggressive and a conservative diagnosis for each lesion. Sequential intra-oral photographs were made during stepwise dissection of the lesion at the time of cavity preparation. A novel reference device placed on the teeth during photographs allowed for accurate measurement of the clinical lesion depth in the axial direction and at its greatest depth. Conversion of the measured values to categorical scores using the same 8-point scale allowed for comparison of the radiographic data with an absolute value or gold standard. Cavitation status of the proximal enamel surface was also noted during treatment, along with the findings of visual, tactile and FOTI examinations.
Results: Both conservative and aggressive radiographic interpretation significantly underestimated the true clinical extension of the carious lesions (p<0.0001) by 1.81 and 1.31 mean categories (0.91 and 0.66 mm) respectively. No significant differences were observed between molars and premolars or maxillary vs. mandibular teeth. Sixteen of the 62 lesions were cavitated (26%).
Conclusions: Diagnoses made from Insight™ film underestimated the true axial extension of interproximal caries by approximately 0.66-0.91 mm. No significant differences existed between tooth types or arch locations. Supported by Delta Dental of Michigan