Using cross‐sectional near whole population‐level data on 318,321 four‐year‐olds attending NZ’s national health and development “B4 School check”, these researchers investigated ethnic‐specific deprivation gradients in early childhood dental caries experience across 6 fiscal years (2010/2011 to 2015/2016). Deprivation gradients were assessed with the Index of Multiple Deprivation, which measures 7 domains of deprivation across 5,958 geographical areas (“data zones”). Ethnicity was categorised as Māori, Pacific, Asian, Middle Eastern, Latin American and African, or European & Other (combined). The “lift the lip” screening tool was used to estimate experience of any caries and severe caries. Reports of any caries experience fell from 15.8% in 2010/2011 to 14.7% in 2015/2016; reports of severe caries experience increased from 3.0% to 4.4% from 2010/2011 to 2015/2016. This varied by ethnicity; Pacific children had larger increases in severe caries – from 7.1% to 14.1%. A random intercepts model estimating mutually adjusted associations between deprivation, ethnicity, age, fiscal year, and evidence of any dental caries experience revealed deprivation gradients in dental caries experience with considerable variation by ethnicity and by domain of deprivation. The association between deprivation and dental caries experience was weakest for Asian children and was most pronounced for Pacific and Māori children.
