Background: Most of the developed world has seen some substantial improvements in the dental health of children over the past four decades owing to advances in service access, fluoride exposure, socio-economic development and improved diets, with the DMFT score of 12 year-olds dropping from well over 10 down to around one. Aim: To examine the question of advancing dental health for children even further using the same set of tools as we have to date by asking the question: Have we come to a point of diminishing returns? The study examines the long-term, near optimum settings of the known public dental health variables in the Australian Capital Territory. Results: Despite having the most ideal and persistent dental health optimised situation, there remains underlying dental caries at a severity level of just below 1 DMFT (12 year olds), and over the last decade the rate of diminishing incidence and prevalence of decay has slowed and arguably stopped. Conclusion: This suggests that rather than toiling to eliminate dental decay completely, the focus might usefully be reoriented towards those small known pockets of society with persistent higher levels of disease and looking for new ways to address these difficult clusters, while simultaneously advancing the understanding that a small residual level of decay will always exist in society. © BASCD 2017.