Substantially aqueous-free, enamel protectant and enamel repair toothpastes containing: stannous fluoride, calcium and a substantivity agent comprising: an emulsion of polydimethylsiloxane in a nonionic surfactant, wherein: (a) substantivity of said stannous fluoride and calcium into biofilm present on enamel is enhanced through calcium binding shifting from bidentate to monodentate in the presence of stannous fluoride； and (b) said toothpastes indicate substantially improved, enamel protectant factor (EPF) and enamel repair factor (ERF) values compared to fluoride brushing treatments with comparable or higher fluoride levels.
