CARIOGENIC POTENTIAL OF FOODS .2. RELATIONSHIP OF FOOD COMPOSITION, PLAQUE MICROBIAL COUNTS, AND SALIVARY PARAMETERS TO CARIES IN THE RAT MODEL

A series of rat caries experiments was carried out to test the relativ e cariogenic potential and to identify the major cariogenic elements o f 22 popular snack foods. Parameters that were measured included rat c aries, number of cariogenic bacteria in plaque, salivary parameters in cluding flow rate, buffering capacity, total protein, lysozyme and amy lase content, and composition of test foods including protein, fat, ph osphorus, calcium, fluoride, galactose, glucose, total reducing sugar, sucrose, and starch. Many interesting relationships were observed bet ween food components, numbers of plaque bacteria, salivary components, and specific types of carious lesions. Protein, fat, and phosphorus i n foods were all associated with inhibition of both sulcal and buccoli ngual (smooth-surface) caries. Food fluoride was associated with inhib ition of buccolingual caries, whereas calcium was related to inhibitio n of sulcal caries. Glucose, reducing sugar, and sucrose in foods were all related to promotion of both sulcal and smooth-surface caries. Th e numbers of Streptococcus sobrinus in plaque were associated with pro motion of smooth-surface caries only, whereas lactobacilli, non-mutans bacteria, and total viable nora were related to promotion of both smo oth-surface and sulcal caries. The salivary flow rate was associated w ith inhibition of both buccolingual and sulcal caries. Salivary buffer ing capacity (at pH 7) and salivary lysozyme delivery were associated with inhibition of number and severity of sulcal caries, while the sal ivary amylase content was related to the promotion of the number of su lcal lesions.