Objective: Non-utilisation of dental care during adolescence can result in poorer oral health and subsequently higher expenditures on dental services. This study examined the geospatial and epidemiological factors associated with the utilisation of the publicly funded Adolescent Oral Health Services (AOHS) in Canterbury, Aotearoa New Zealand (NZ).

Methods: A secondary analysis of prospectively collected routine data from AOHS visits of adolescents in school Year 9 (13-14 years) for the financial year 2019-2020. Geographic Information Systems examined distance from home address to dental practices. Multilevel mixed- effects Poisson regression models investigated associations between geospatial, demographic and clinical factors and non-utilisation of dental services. Models were adjusted for sex, ethnicity, area- level deprivation, rural/urban classification, previous caries experience, and the distance from home address to dental practice referred.

Results: Dental practices were concentrated in large urban areas and in the least deprived neighbourhoods, with several service area gaps identified. Rural areas and the most deprived areas of Christchurch City had the highest non-utilisation rates. After adjustment, adolescents residing in the most deprived areas had a higher risk of non-utilisation (adjusted risk ratio [aRR]=1.38 (95% CI 1.26-1.51) compared to adolescents in the least deprived areas. Adolescents in remote areas also had an increased risk of non-utilisation (aRR=1.36; 95% CI 1.20-1.54) compared to adolescents in urban core areas. Finally, Māori (aRR=1.37; 95% CI 1.29-1.46) and Pasifika (aRR=1.46; 95% CI 1.35-1.59) adolescents had significantly higher risks of non-utilisation compared to their NZ European counterparts.

Conclusion: Inequitable access to publicly funded dental care exists among adolescents in Canterbury, NZ, which negatively impacts Māori, Pasifika, and those living in rural and most deprived areas. Adolescents at the greatest oral health risk are geographically underserved by current oral health services. The current health system could explore the possibility of partnering with Māori and Pasifika communities to provide services within culturally appropriate settings.