Social inequality in dental caries and changes over time among Indigenous and non-Indigenous Australian children.

OBJECTIVE: This paper describes and compares magnitudes of socioeconomic (SES) inequalities in oral health among Indigenous and non-Indigenous children over a 10-year period.

METHODS: We analysed annual oral health survey data from NSW, NT and SA. Data were extracted for time period 1 (2000-2002, N=215,317) and time period 2 (2007-2010, N=34,495). Oral health outcomes were untreated decayed deciduous teeth (dt) and cumulative dental caries experience (dmft). Postcode-level Socioeconomic Index for Areas was used to assess SES. Age standardisation and complex survey weights were used. Indices of socioeconomic inequality in health (Slope Index of Inequality, Relative Index of Inequality, Absolute and Relative Concentration Index) were used to quantify inequality in dental caries and its changes over time.

RESULTS: Oral health outcomes deteriorated in both Indigenous and non-Indigenous populations over time. Indigenous children experienced higher levels of disease at both times. Untreated dt increased in both populations. The cummulative disease (dmft) increased at higher rate among children in low-SES areas in both populations. Over time, there was an increase in socioecononomic inequalities in dmft in all children and in dt in non-Indigenous children.

CONCLUSION: Area-level socioeconomic inequality in child oral health has widened due to deterioration in low-SES children.