Cariogenic potential of fruits in rats after programmed feeding and dietary intubation

The potential cariogenicity of commonly consumed fruits was evaluated with a programmed feeding regime using gastric intubation. After infection with a pure strain of S. Mutans 6715, seventy 22-day old, Sprague Dawley rats were randomly assigned to groups receiving the following foods 17 times per day: I. sucrose, II. fresh apples, III. freeze-dried apples sifted through a No. 20 sieve, IV. fresh bananas, and V. fresh oranges. All groups received 2 mls of National Caries Program No. 2 liquid diet twice daily. Intake of test foods was measured daily while weight and length of animals were measured twice weekly. After 35 days, the animals were decapitated and the mandibles stained and scored following the Keyes technique. Total caries appeared in the groups in the following decreasing order: bananas, oranges, apples, freeze-dried apples, sucrose.