Cariogenicity of three foods in rats receiving essential nutrients by gastric intubation.

The objective of this study was to determine the cariogenicity of 3 foods similar in texture, but varying in their sucrose concentration. The foods were evaluated in rats in which essential dietary nutrients were administered by gastric intubation. A modified Scow diet was used for the intubation procedure, administered twice daily over a 21-day experimental period. The test foods (Kellogg’s Corn Flakes, Kellogg’s Frosted Flakes, and Kroger’ s Vanilla Wafers), each were provided ad libitum to 3 groups containing 20 weanling Wistar (Harlan) rats each. The evaluation of sulcal caries was performed according to the methods of Keyes. The vanilla wafers group containing 45% sucrose had significantly fewer carious lesions (9.4 +_ 1.4) than did the presweetened corr,, flakes group (14.3 +_ 1.0) containing 35% sucrose (p < 0.05). The unsweetened corn flakes group (12.7 +0.7) containing 8% sucrose was not significantly different from the other 2 groups in caries scores (p > 0.05). With regard to growth, the vanilla wafers group had a significantly higher weight gain than did the other 2 groups during the experimental period. Various methods have been used to predict the cariogenicity of human foods. These methods include human clinical studies and investigations of the following: food acid produced in incubated saliva, acid formation in dental plaque, food retention in the mouth, enamel decalcification by foods, in vitro caries, and animal caries. Each of these methods has its inherent strengths .and weaknesses. If practical recommendations are to be made so that consumers can choose foods that are less likely to produce caries, information must be obtained on the caries-producing potential of a great variety of sugaror starch-containing foods, especially the new types of presweetened foods which appear almost daily in the food market. ~ A fast, economical method of evaluating cariogenicity of foods is needed. As a result of the widespread incrimination of sucrose, 2 the opinion sometimes has arisen that other sugar sweeteners such as fructose and high-fructose corn syrups are either noncariogenic or are significantly less cariogenic than sucrose. Recent investigations in primates have shown that mixtures of glucose and fructose are as cariogenic as sucrose and that little benefit would be derived by substituting fructose for sucrose. However, in a normal human diet, sucrose and other sugars per se seldom are consumed on their own and usually are ingested as an ingredient of food or applied directly to food by the user. Consequently, attempts have been made to avoid a total condemnation of sugar-containing products and to assess the cariogenic potential of each product on its own merit. For ethical and pragmatic reasons, it is impossible to determine the cariogenicity of a wide range of food in humans. Likewise, although primates 3 give caries results which may be directly applicable to man, they are expensive, large, difficult to work with and thus are not appropriate for large-scale screening of the cariogenicity of foods. As a result, the rodent may be the most appropriate animal caries model in view of its small size, relatively low cost, and susceptibility to rapid development of caries. With regard to the cariogenicity of foods, ready-toeat breakfast cereals, especially the presweetened forms, have been suggested to have a high cariogenic potential on the basis of high sugar content and their retentive nature in the oral cavity. However, results are inconclusive and sometimes contradictory. 4 278 CARIOGENICITY OF THREE FOODS: Beiraghi et al. Based on the results of past experience, it appears that the caries-producing capability of food could be evaluated better if it could be consumed as the only food item to pass through the oral cavity. Otherwise, the results of tests might be in response to other dietary factors rather than the specific food tested. Also, it has been recognized for several years that rats which consumed their entire diet by gastric intubation remain caries-free and can be kept in good health. 3 This study evaluated the caries-producing capability of the following 3 specific food items when they were provided as the sole food to pass through the oral cavity of rats: unsweetened corn flakes cereal, a vanilla wafers, b and presweetened corn flakes cereal. c Methods and Materials Sixty inbred male Wistard rats 40-50 g were distributed randomly into 3 equal groups. All animals in each group were housed in pairs in sanitized stainless steel, raised-wire cages so that all animals of I group were together. The rats were maintained on a common commercial diet e and deionized drinking water ad libitum until they were 3 days old. All animals were provided a modified Scowf diet administered by gastric intubation at 7 AM and 5 PM daily. The diet tubing apparatus consisted of a 10.0 ml Luer-lok syringe fitted with polyethylene tubing. Water was added to the dry diet daily in a ration of 1.3 g of water/1.0 g of diet. The 3 groups and food items were as follows: Group Test Food Item A Corn flakes cereal