Abstract
In order to assess the prevalence of untreated caries in two groups of Danish 7th grade (13‐ to 14‐year‐old) schoolchildren in a blind study, a radiographic investigation was carried out. Only half of the children (394) had received regular school dental care during their years of attendance of primary school; the other children (368) had not. A bitewing radiograph of the right side of the mouth of each child was taken, employing a standardized technique. The radiographs were read without the examiner knowing the group identity of the radiographs. The criteria for discarding poor radiographs, teeth, and tooth surfaces are described. Some of the radiographic results are compared with the clinical caries score of the same group. Most of the radiographs without untreated caries were found among those of the children who received school dental service. Uncertainly of method in connection with radiographic investigation is discussed.