Relationship of the macroscopic, histological, and radiographic appearance of interproximal lesions in human teeth: in vitro study using artificial caries technique

Introduction It is well accepted that the use of bitewing radiography is an important adjunct in the diagnosis of interproximal caries. However, the relationships between the macroscopic, clinical, and radiographic appearance of a carious lesion and its true extent in the tissues may not be fully realized by the clinician, especially since there is both confusion and controversy in the literature. In a detailed in ~itro investigation on 580 extracted teeth, Marthaler and Germann1 found that when radiolucencies were limited to the outer enamel, frank cavities were present in 34 percent of the teeth. When the bitewing radiolucencies extended into the inner aspects of the enamel, cavities were present in 66 percent of the teeth. This demonstrates just how advanced lesions really are in spite of what can appear to be "early" detection by radiography. These workers also showed that when a radiolucency was visible in the outer half of the dentin, small cavities were present in 87 percent of the surfaces. All of the radiographs in the above study were taken without using a soft tissue simulator and therefore represented a greater degree of sensitivity than could be achieved clinically. It was also reported by Leijon~ that a greater number of carious lesions could be detected by extraoral inspection with the unaided eye compared with dental radiographs taken extraorally, even without using a soft tissue simulator. When radiographs were taken clinically, an additional number of radiolucencies were masked by soft tissues. Of 169 approximal surfaces diagnosed as sound enamel by in ~4tro radiography, macroscopic inspection revealed 50 white spot lesions. 3