Objective: The prevalence of caries in Australian children has declined appreciably since recordings commenced at the conclusion of the Second World War. In the period 1945-1955, 12-year-old DMFT scores were recorded as ranging between an average of 7 and 12 teeth. In 1998, children caries experience reached an historical low: 6-year-old mean dmft was 1.51 and 12-year-old mean DMFT was recorded as 0.83 teeth. Despite the dramatic reduction in children caries in Australia there is recent evidence that the decline in children caries may have come to an end. The purpose of this study was to examine the trend in children caries experience for Australia nationally, and for South Australia. Method: Models were constructed from two time series: data starting from 1977, and a restricted sample of more recent data from 1989 onwards obtained as part of a continuous national monitoring survey. All children were sampled during their regular examination conducted by the School dental service, a free service provided throughout Australia to primary school children. Linear and curvilinear regression models were used to estimate the trend between these years and then project that trend to future years to get the medium projection.
Results: For all models quadratic equations showed the best fit for the data. While the Australian data showed a levelling off in caries experience up to 1999, more recent data from South Australia indicated the beginning of an increase in children caries, both in the deciduous and permanent dentition. Effect sizes were very high for South Australia, with model fits based on the quadratic curve up to R2 = 0.99 in the deciduous dentition and R2 = 0.98 in the permanent dentition.
Conclusion: The implications of recent increases and projected trends in children caries experience are significant for Australia and other low-caries prevalence countries.
JM Armfield*, AJ Spencer
Presented at the 81st General Session and Exhibition of the IADR, 25-28 June 2003, Goteborg, Sweden