Dental caries disparities in early childhood: A study of kindergarten children in British Columbia.

Objective: The objective of this paper was to describe results of a public health-administered, provincial dental survey of children aged 4-6 years old in British Columbia, and assess the changes in rates of dental caries geographically and by neighbourhood socio-economic status between baseline (2006/07) and follow-up data collection (2009/10).
Method: The study design involved two retrospective cohorts of kindergarten children who received a public health-administered dental assessment in the years 2006/07 and 2009/10. Neighbourhood socio-economic status was measured by an index created from Canadian Census and Tax Filer data sets. The dental outcomes included previous decay experience, untreated visible decay, and urgent treatment needs.
Results: The analysis comprised dental outcomes for 35,602 kindergarten children in 2006/07 and 35,215 children in 2009/10. There was a modest decrease in dental decay rates between surveys, with rates of decay experience - previous and untreated - of 38.9% and 36.7% respectively. However, there were disparities, with almost 50% of children with dental decay in the most socio-economically disadvantaged neighbourhoods, and approximately 30% with dental decay in the least disadvantaged areas.
Conclusion: The kindergarten dental survey had extensive coverage, was at the population level, and enabled analysis of change in early childhood dental decay rates over time and by geography. Although overall rates improved, dental health inequalities persisted in both survey years at both regional and neighbourhood levels.