A radiographic method for distinguishing noncavitated from cavitated proximal carious lesions: A proof of concept clinical trial.

Objectives: We propose a new topical radiographic contrast method for distinguishing noncavitated from cavitated radiolucencies. Laboratory tests and a pilot clinical trial were designed to test the feasibility and efficacy of the method.

Study Design: Twenty-two adults with 27 proximal radiolucencies had conventional bitewing (BW) examinations. After exclusion, 21 surfaces were evaluated. A concentrated solution of sodium iodide was placed in the interdental spaces via a microsyringe and BWs were again exposed. A class II cavity preparation was made in the adjacent tooth and polysiloxane impressions were made of the study surfaces. The impressions were scanned by visible light, creating a high resolution 3D replica. Cavitations, if present, were measured.

Results: Nine surfaces were noncavitated and 12 surfaces were cavitated. The microsyringe dispensed a variable volume of liquid, which affected the accuracy of the test. The sensitivity for cavitation was 50%, specificity was 88.9%, and accuracy was 66.7%. This compares to a reported 60% sensitivity, 62% specificity, and 62% accuracy for BW examinations. Intraexaminer reliability for classifying noncavitated or cavitated lesions using the kappa test was 0.649.

Conclusions: This method needs improvement but was an advance over conventional BWs and could result in reduction of restorations in low- and high-risk patients.