The aim of this study was to determine the additional diagnostic value of bitewing radiographs compared to clinical examination, with respect to the presence of dentine lesions and inadequate restorations for different age groups. Subjects were 14-, 17-, 20-, 23-years-old, or were in the age groups of 25-34 and 35-54 years, who participated in 2 clinical epidemiological surveys. After obtaining informed consent, bitewing radiographs were made of approximately 25% of the participants (n = 663). The extra diagnostic yield of the bitewing radiographs varied between a factor 1,6 and 7,2 for approximal dentine caries diagnosis of untreated surfaces, and between 2,3 and 5,9 for inadequate restorations. In conclusion, a considerable increase in the numbers of approximal dentinal lesions and inadequate restorations for all age groups was found.