Associations between ethnicity, socioeconomic status and dental caries in children: A population-based record linkage longitudinal cohort study.

This study aims to examine the associations of ethnicity and socioeconomic factors with obvious dental caries and assess longitudinal changes between 5 and 11-years of age. A retrospective longitudinal design was employed, linking individual-level health and education records for children aged 5 and 11-years living in Scotland between 2004 and 2018 (n = 155,737). At age five, Polish and Gypsy/Traveller children had around four times higher odds for developing obvious caries compared to White Scottish peers (OR = 4.37, 95% CI: 3.87-4.94) and (OR = 3.47, 95% CI: 2.52-4.79) respectively. By age 11, African, Chinese, Indian, and White British children showed lower odds of developing obvious caries, while Gypsy/Traveller (OR = 2.70, 95% CI: 1.98-3.70), and Polish (OR = 1.34, 95% CI: 1.18-1.52) children remained at elevated risk compared to White Scottish children. Longitudinal analysis revealed limited overall ethnic differences in new obvious caries development, though African (OR = 0.51, 95% CI: 0.39-0.67) and Chinese (OR = 0.58, 95% CI: 0.38-0.90) children were less likely to develop new obvious caries compared to White Scottish children. Several minority groups, including Polish, Gypsy/Traveller, Pakistani, and Arab children, demonstrated improvements in caries status between ages five and 11 compared to White Scottish children. Obvious caries presence at age five is strongly associated with caries at age 11 (OR = 3.24, 95% CI: 3.16-3.33). Ethnic disparities in obvious dental caries were evident at age 5 and independent of socioeconomic status. By age 11, these inequalities diminished for most groups, with socioeconomic factors emerging as the primary drivers of oral health inequalities, except among Gypsy/Traveller and Polish children.