Evaluation of examiner variability and the use of radiographs in determining the efficacy of community fluoridation

Abstract

DMF tooth and surface data of 11- and 12-year-old children living in a fluoridated and a low fluoride community have been obtained by two examiners, working independently. One examiner (A) used only visual findings and the other examiner (B) used visual and visual-plus-radiographic findings in making an evaluation of fluoridation. A slight but consistent difference in the level of caries-detection was demonstrated in the visual findings of the two examiners; examiner A tended to record more carious surfaces than examiner B. Very similar percentage differences were shown, however, in the caries prevalence of the children in the two communities by each examiner's sets of data. Approximately 25 per cent more carious teeth and one-third more carious surfaces were diagnosed in each community when examiner B's radiographic findings were added to his clinical findings, but the addition of radiographic findings did not appreciably alter the relative difference in caries prevalence in the two communities based on his visual findings alone. The dental benefits of community fluoridation are apparent in this report. An average of the results obtained by the two examiners showed that children in the fluoridated community had 40 per cent fewer DMF teeth and 50 per cent fewer DMF surfaces than their counterparts in the low fluoride community. According to examiner A's visual findings, 18 per cent of the 12-year-olds in Fargo had zero DMF surfaces, whereas only 1 per cent of children that age in Moorhead were free of carious surfaces. The protective effect of fluoride was found to be strikingly more apparent on approximal surfaces than on occlusal or buccal-lingual surfaces.