Diffusion phenomena during artificial carious lesion formation

Artificial carious lesions were produced in human enamel using lactic acid [HL] buffers plus diphosphonate [MHDP]. Surface layer thickness was related to [MHDP], middle zone (body) and inner zone depths to [HL] and pH. Indications are that diffusion in enamel is predominantly by unionised species such as HL and CaHPO4, and dissolution by H+ and L-.