Dental aspects of the consumption of xylitol and fructose diets.

126 voluntary test persons, divided into three groups, were put for two years on a strict diet with regard to the sweetener used (sucrose, fructose, and xylitol). The test persons were investigated in the frame of a versatile clinical, radiographical, biochemical, microbiological, and medical research plan. The consumption of the fructose and xylitol diets did not result in any pathological changes in the test persons' whole saliva, plaque, blood, and urine samples. The consumption of the xylitol diet reduced the incidence of dental caries by approximately 90 per cent when compared to sucrose consumption. In the fructose group the reduction was 30 per cent. Xylitol consumption reduced the growth of dental plaque by 50 per cent during the whole two-year period. It also reduced the concentration of lactate in plaque and whole saliva and the ability of plaque and whole saliva to yield reducing sugars from sucrose. Simultaneously, the activity of the salivary lactoperoxidase was strongly increased. These and certain other dentally advantageous chemical changes indicated that the mechanism of the xylitol effect is dual, being partly systemic and related to a selective effect on the production of salivary enzymes and on the electrolyte concentration of whole saliva, and partly local, depressing the growth of cariogenic and certain other microorganisms.