The percentage data was expressed as proportion and the square root of each value was arcsine transformed. However, the change has not been directional, and the proportion of children with disease appears to have remained constant. Beneath this overall uniformity, changes in the make-up of the disease have occurred. Discussion Dental caries among five year olds appears to be changing in Great Britain. At the same time, less of the extant disease is being treated restoratively.
Sufficient data is now available to examine changes in epidemiological measures through time.
Complete records of D3MFT and its components are available for 131 health districts in England, all 9 districts in Wales and all 15 health boards in Scotland for twelve year olds in 1988 and 1992. Complete records of D3MFT and its components are available for 151 health districts in England, all 9 districts in Wales and all 15 health boards in Scotland for fourteen year olds in 1990 and 1992. Analyses were undertaken using paired t-tests. However, the change has not been common to all components. D3T has increased, while both MT and FT have fallen.