Medical-Grade Nano Hydroxyapatite Particle Specs and Enamel Combination The APAGARD PREMIO enamel repair toothpaste with nano hydroxyapatite uses crystalline calcium phosphate bits [Ca10(PO4)6(OH)2] manufactured at nanometer range with typical size of 50-100 nanometers, making it possible for penetration right into enamel micropores and subsurface demineralized areas gauging 1-10 micrometers deepness. This fragment dimension matches the …