Abstract
In managing dental caries, the ability to distinguish between non-cavitated and cavitated lesions is crucial since the former can be treated by non-surgical methods. Interproximal caries relies mostly on radiographic assessment and current methods are unable to distinguish between non-cavitated and cavitated lesions. The goal of this research was to determine by an in vitro pilot study if a concentrated aqueous solution of sodium iodide applied topically to the interproximal surfaces of extracted teeth can discriminate radiographically between non-cavitated and cavitated natural carious lesions. Human pre-molar extracted teeth stored in thymol were collected in the Omaha area. 12 sound, cavitated, and non-cavitated white spot lesion surfaces were used for the experiment. Control exposures were made using Gendex Gx-770, 70 kVp, 0.1 secs, 7 mA with the digital intraoral sensor, XDR radiology (Cyber Medical Imaging, Los Angeles, CA), 8 cm source to digital sensor, 6 mm center of tooth to sensor. A 9 molar solution of sodium iodide (NaI) in distilled water was made and placed on the interproximal surfaces of the test teeth. Teeth were radiographed and two authors read the images for the presence or absence of opaque regions after NaI application compared to controls. The non-decalcified teeth were sectioned using a diamond saw (Scientific Fabrications, Littleton, CO, USA) and photographed dry (Olympus DP71, 12.5 megapixel camera) mounted on a steriomicroscope. Presence of caries determined visually. It was determined that 11 of 12 cavitated lesions had radiopacities but not the non-cavitated or sound surfaces. The results indicated that a concentrated solution of NaI quickly produces a radiopaque region in cavitated but not in non-cavitated or sound teeth.