Reasons for local differences in mean DMFT-score

Methods: Four pairs of bite-wing radiographs and a form were sent to 13 PDS units. The dentists were asked to analyse the radiographs three times, thinking in each case of one of the following patient situations: 1. no previous caries experience; 2. recall patient with caries risk; 3. new patient with poor oral hygiene. Participants were asked to analyse each tooth surface (173 surfaces) and choose one of the given alternatives: 1. sound; 2. caries lesion to be observed; 3. caries lesion to be actively prevented; 4. caries lesion to be restored. A chi-square test was used and the level of significance set at 0.05. Ninety-two dentists answered; 49 worked in PDS-units reporting low (≤1.5) and 43 high (>1.5) annual mean DMFT-scores for 12-year-olds.

Results: Of all patient cases, the participants suggested a mean of 131 surfaces to be sound, 12 surfaces to observe, 14 surfaces needing active prevention and 16 surfaces to be filled. Dentists working at “high” DMFT PDS units suggested significantly fewer sound surfaces and more carious lesions to be restored. When analysing the patient cases separately, no difference between the dentists in “high” and “low” DMFT PDS units were found.

Conclusions: Dentists working in “high” DMFT PDS-units tended to diagnose fewer sound surfaces and suggest more restorations than those in “low” DMFT PDS-units.