Inequalities in dental caries in children within the UK: Have there been changes over time?

To examine any change over time in the association between deprivation and caries experience between 2003 and 2013 in a nationally representative sample of UK children.

Data from UK Children's Dental Health Surveys, 2003 and 2013, were used. The target population was 5-, 8-, 12- and 15-year-olds. A total of 9604 children in 2003 and 9866 in 2013 were included in the surveys. Outcome variables were any active caries, caries experience and total number of carious teeth. Family socio-economic position (SEP) or deprivation level was measured at school level using eligibility for free school meals (FSM) to identify children from low-income families. Incidence rate ratios (IRR) and pooled standardized incidence rates ratios were calculated to measure dichotomous outcome variables by year, age group and status of deprivation. The study continuous outcome was modelled using a zero-inflated Poisson regression while the dichotomous outcomes were modelled using logistic regressions. The multivariable analyses were run by age groups accounting for year, sex and deprivation status.

The percentage of those identified as deprived was significantly higher in 2013 (35.8% in 2013 vs 26.0% in 2003, P < 0.001). Among both deprived and non-deprived children, the prevalence of any active caries significantly dropped over the years, observed in all age groups. Comparing 2013 with 2003 and accounting for sex, deprivation level, "any active caries," "any caries experience" and "total number of carious teeth" significantly dropped were observed in all age groups. Comparing the years, the association of deprivation with caries outcomes mostly remained the same or decreased. This decrease was predominantly seen in "any caries experience." Only among the 5-year-olds, did the association between deprivation and total number of carious teeth over the years significantly increase. For all age groups, the likelihood of "any active caries" and "total number of carious teeth" by deprivation remained the same comparing the two points in time: 2003 and 2013. However, irrespective of year, deprivation was significantly associated with caries observed in all age groups.

In the UK, the prevalence of active dental caries and caries experience has decreased in the period between 2003 and 2013. Similarly, the likelihood of having dental caries by deprivation in 2013 was predominantly lower than that observed in 2003.