The prevalence of clinically undetected occlusal dentine caries in Scottish adolescents.

During the third examination of a 3-year anti-caries dentifrice study, bitewing radiographs were read to detect occlusal, as well as approximal caries lesions in 2623 subjects aged 14-15 years. These analyses showed that 1.4% of 2107 upper molars and 7.2% of 2288 lower molars (P less than 0.001), previously scored as clinically 'sound', were carious at a radiographic Grade '3' score (dentinal involvement), and 0.2% had radiographic pulpal lesions. However, for teeth which had been deemed as having a 'suspicion' of caries clinically, but which a 0.6 mm blunted probe would not enter, 29.1% of lower molars had definite radiographic evidence of dentinal caries as compared to only 7.6% of upper molars (P less than 0.001), and a further 0.5% exhibited pulpal extension. In addition, 23.9% of lower premolars also showed dentinal involvement in this group. Overall, 12.1% of lower molars and 3.1% of upper molars showed definite radiographic evidence of occlusal caries in the absence of a firm clinical indication. Thus, the use of bitewing radiographs would appear to be a most helpful adjunct to clinical caries diagnosis, not only of approximal lesions, but also for the detection of early occlusal caries, in these days of generally available topical fluoride.