ACCUMULATION OF FERMENTABLE SUGARS AND METABOLIC ACIDS IN FOOD PARTICLES THAT BECOME ENTRAPPED ON THE DENTITION

Earlier studies (Kashket et al., 1991) showed that particles of high-s tarch snack foods remained longer on the teeth than those of high-sucr ose, low-starch foods. The question arose whether the prolonged presen ce of food particles enhances cariogenicity. A study was undertaken to measure sugars, starches, and metabolic acids in retained food partic les. Subjects consumed portions of different foods, and particles were removed from all bicuspids and first molars at defined times after sw allowing. Dry weights, sugars, and short-chain carboxylic acids were d etermined. High-sucrose foods were cleared rapidly from the teeth, whi le high-starch foods were retained for up to 20 min. Sucrose, glucose, and fructose persisted in the retained particles. Particles of high-s tarch foods accumulated maltose and maltotriose, presumably from the b reakdown of starch by salivary amylase. At maximum, maltose plus malto triose constituted 94% of total sugars in particles of potato chips; c orresponding values in doughnuts, peanut butter cookies, and salted cr ackers were 43, 51, and 61%, respectively. Total fermentable sugars in the particles of high-starch foods were similar to those for the high -sucrose confectionery products. Carboxylic acids accumulated within t he particles, presumably due to the fermentation of the sugars by entr apped salivary micro-organisms. At maximum (5 to 7 min), acetic, formi c, lactic, and propionic acids rose 17-, 30-, 15-, and 1.3-fold, respe ctively, in dough-nuts, and to smaller degrees in potato chips, salted crackers, and chocolate-caramel-peanut bars. In summary, the study de monstrated the persistence of sugars, the progressive accumulation of starch breakdown products, and the fermentation of the accumulated sug ars in retained food particles. The findings support the view that hig h-starch foods contribute to the development of caries lesions.