The cariogenic potential of foods--a critical review of current methods.

Current methods used in examining the cariogenic potential of foods are plaque pH measurements, measurements of adhesiveness of foods, experimental caries models and animal tests. pH measurements can be used for separating the non-acidogenic foods from the acidogenic ones but they are not suitable for separating foods with different levels of caries inducing potential. This is illustrated by the fact that virtually all foods which contain carbohydrates cause the pH of human plaque to fall below 5.5. Cooked rice and beans also give such a pH drop but these foods have a very low caries-inducing potential, as shown in studies of persons with hereditary fructose intolerance. Furthermore, experimentation has shown that acid formation and enamel dissolution are not directly correlated. Animal models exist in which various test foods can be examined under identical conditions. By using the same microbial challenge and a reference food, for example sucrose, the relative cariogenic potential of a test food can be calculated. One limitation with these animal models is that the foods have to be given in powdered form and not in the physical form in which they are consumed by humans. The main objection against most of the current methods is that they reflect important factors in our concept of the pathogenesis of dental caries only to a limited extent. For example, only the animal tests can be used to illustrate the extent to which foods support the colonization of S. mutans on teeth. The qualitative composition of the plaque is practically never considered. A series of tests can, however, be combined to give more relevant information about the caries-inducing potential of foods.(ABSTRACT TRUNCATED AT 250 WORDS)