Hardness changes and mineral loss in enamel during the intra oral cariogenicity test in the presence of 0.125% EHDP with or without 0.1% F-.

The effects of a high EHDP concentration (0.125%) were measured under Intra Oral Cariogenicity Test (ICT) conditions in the presence or absence of F- (0.1%). EHDP as well as EHDP supplemented with F- inhibited the softening of enamel slabs to a similar extent as measured by microhardness. Measurements of the calcium and phosphate levels as a function of depth showed that the addition of F- to the EHDP solution further decreased mineral loss in the deeper layers. The results suggest that the inhibition of demineralization of the enamel by EHDP and F- is due to inhibition of acid production by microorganisms.