THE EFFECT OF RESIDENCE AND SOCIAL-CLASS ON DENTAL-CARIES EXPERIENCE IN 15-16-YEAR-OLD CHILDREN LIVING IN 3 TOWNS (NATURAL FLUORIDE, ADJUSTED FLUORIDE AND LOW FLUORIDE) IN THE NORTH-EAST OF ENGLAND

Caries experience in 1374 children aged 15-16 years from three towns in the north east of England with varying concentrations of fluoride in drinking water, was determined. The mean DMFT values for 15-year-old continuous residents was 1.7 in Hartlepool (natural F 1.0-1.3 ppm), 2.5 in Newcastle (F adjusted to 1.0 ppm) and 3.3 in Middlesbrough (F = 0.2 ppm). Forty per cent of Hartlepool 15-year-olds were caries free, compared with 30% in Newcastle and 24% in Middlesbrough. Caries prevalence for both Hartlepool and Newcastle 'continuous residents' was lower than for non-continuous residents, whereas in Middlesbrough, the low fluoride area, non-continuous residents had a lower DMF value than those who had lived in Middlesbrough all their lives. There was a slight trend in both Newcastle and Middlesbrough for DMFT values to increase from social class I to social class V, but no discernable trend was observed in Hartlepool. The results for Hartlepool 15-year-olds were very similar to those reported by Weaver in 1949.