Detection of lesions on contacting approximal surfaces (ie, the sides of adjacent teeth that are touching each other) of posterior teeth is also a challenge, and the inadequacy of clinical visual and tactile methods is the reason that use of ionising radiation for bitewing radiographs is still sanctioned. However, the same systematic review of high quality studies showed that, for approximal surfaces, radiographs had an overall sensitivity of 50% and a specificity of 87%.
Thus, using conventional clinical and radiographic methods, the dentist will detect only about half the lesions present and, could misclassify sizeable numbers of sound surfaces as decayed. Radiographs are not very helpful for anything but advanced dentinal lesions on occlusal surfaces (sensitivity 39%, specificity 91%).
The consequence of diagnostic errors depends on the treatment strategy used.