Considering the in vitro nature of this study, it can be concluded that, for enamel, calcium lactate pentahydrate and sodium polyphosphate provided the best results regarding erosion reduction and their association seemed to enhance their individual effects. On root dentine, some protection against surface loss was achieved only by the association of calcium lactate pentahydrate and sodium polyphosphate. None of formulations tested achieved the degree of erosion protection found with the commercially prepared orange juice with added calcium.