Degradation of tooth enamel leading to dental cavities is a common health concern as 32% of the worlds’ adult population has had cavities at some time in their lives. Zinc and stannous ions are commonly used in oral care to reduce tooth enamel degradation. However, mechanistic understanding of the role of these ions in the protection of enamel against acid insults remains inadequate due to limitations of experimental techniques to validate interfacial interactions at the atomic scale. This team has overcome this challenge through the examination of adsorption and subsurface exchange of the ions on common hydroxyapatite surfaces in contact with electrolytes at pH values of 5 and 7 through use of molecular dynamics simulations in unprecedented accuracy. The results provide the first quantitative insights into enamel surface stabilization and the methods can be applied to other mineral phases.