These researchers analysed national aggregated data collected from children’s routine child oral health service dental examinations during the period 2004–2013, to analyse patterns in the prevalence of no obvious decay experience (caries-free) and mean decayed-missing-filled teeth indices over time. The researchers obtained demographic information from Statistics New Zealand for children aged 5 years and in school year 8 (generally aged 12–13 years), as well as information on the children’s community water fluoridation (CWF) status, which was defined by the public water supply status of their school. Dental examination data were available from 417,318 children aged 5 years and 471,333 year 8 children; of whom 93,715 (22.5%) and 94,001 (19.9%), respectively, were Māori. Dental examination coverage of Māori children was significantly less than their non-Māori counterparts (approximately 11% for children aged 5 years and 14% for year 8 children). In regression analysis, caries-free prevalence and mean decayed-missing-filled teeth indices significantly improved over the study period for both age groups. Significant and sustained differences were observed between Māori and non-Māori children, and between CWF and non-CWF exposed groups. In contrast, dental profiles converged between non-Māori children in CWF and non-CWF regions.
