32 This selective barrier prevents direct contact between acids and the tooth surface, thus reducing the dissolution www.selleckchem.com/products/Imatinib-Mesylate.html of hydroxyapatite. Protection of the tooth surface by the acquired pellicle is well-established in the literature and has been demonstrated by several studies.33,34 In this in vitro study, there was no acquired pellicle formation, and the absence of this natural protection may have increased the erosive attack on the enamel slabs. In addition, under clinical conditions, the presence of a salivary pellicle might affect the adhesion of proteins on the enamel surface, increasing the protective effect of the studied foods. In this study, enamel wear was used as response variable since it is able to measure the complete dental loss induced by the pH-cycles, thus reflecting the cumulative effect of the erosive challenges.

It has to be taken into consideration that in the contact profilometry, as done in the present study, the stylus might be able to scratch the acid-softened surface.35 However, even when the stylus might damage the surface to a small extent, it is assumed that this phenomenon can be observed in all groups and might not affect possible differences among the groups. The resolution of the profilometer is 0.4 ��m, allowing highly precise wear measurement because the mean erosion depths of the studied groups were higher than the error limit of the equipment. The results of the present study showed that the food contact previously to the erosive challenge minimized the enamel erosion.

This data could be explained by the fat and/or protein content of the tested foods, which could have acted as a physical barrier, thus limiting the action of the acidic drink.36 Lewinstein et al20 hypothesized several mechanisms for caries inhibition by cheese: protection derived from bufferfat, buffering of dietary acids through metabolism of protein breakdown products, and prevention of demineralisation and/or promotion of remineralisation by casein, calcium lactate, ionisable calcium, and phosphate present in dairy foods. Taking these aspects into account, another hypothesis could be related to the calcium (Ca) present in the studied foods. In agreement with the present study, Weiss and Bibby37 showed that bovine enamel exposed previously to cow��s milk was 20% less soluble in acetic acid than the control enamel.

Another ion that could enhance the protective effect of the foods (liver and broccoli) is iron (Fe). The mechanism involved in this protection of iron against mineral dissolution is not completely understood. It is possible that the formation of a thin acid-resistant coating of hydrous iron oxide on the enamel mineral surface may be a possible factor.38 It has been shown Cilengitide that when the enamel is incubated with solutions of ferric salts, acid-resistant enamel surfaces are established due to the precipitation of ferric phosphate on the surface of the enamel.