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.

Fissure sealant presence was recorded at baseline and annually during a 3-year, double-blind clinical caries trial which involved 3005 children aged 12-13 years at outset. At baseline, initially, 2002 sealants were noted in 431 subjects (14.3%), a figure not dissimilar to that found for Scottish 12-year-olds in the UK National Survey completed in the same year. By the fourth examination, 400 (17.3%) children had 2209 surfaces sealed. After one year, 14%, and at 3 years, 26% of baseline sealants were missing. Overall, at the last examination, 25% of baseline unsealed surfaces were carious compared to 15% of those originally sealed (P less than 0.001), although for molars, the equivalent figures were 49% and 24% (P less than 0.001). Finally, analysis showed that at baseline, as few as 15% of sealants had been placed by general dental practitioners, and this low proportion was maintained throughout the study period. While sealant placement in the Scots' age group was low, nevertheless the prevalence recorded was greater, at least by a factor of three, than has been reported elsewhere in the UK.