Dental caries-protective agents in milk and milk products: investigations in vitro

Objectives: To characterise and identify the anti-dental caries components that exist in milk and milk products. Methods: Standard enamel or hydroxyapatite demineralisation tests were devi sed to simulate the action of acid on tooth mineral, and they were used to show which constituents of milk possessed a potential protective action aga inst acid attack. Results: Milk and milk products were fractionated and tested. revealing tha t minerals, including calcium and phosphorus, played a part in this protect ive process. The findings also drew attention to the effectiveness of minor milk protein or protein-associated components, the structures of which are mostly known, which were separated and characterised by gel electrophoresi s as proteose-peptone fractions 3 and 5. The strength of adsorption of the protein or polypeptides in these fractions to dental enamel was measured an d found to be sufficient to reduce the extent of demineralisation of enamel by acid buffer solutions. Conclusions: The removal of lactose, fat, casein and other proteins had lit tle influence on the protective effect of the milk fractions. Besides calci um and phosphorus, milk contains other more powerful protective factors, wh ich were identified as proteose-peptone fractions 3 and 5. Details of their composition and the strength of their adherence to the surface of dental m ineral are given. (C) 2001 Elsevier Science Ltd. All rights reserved.