Erosion of Molar Teeth by Acid Beverages

Abstract

In the case of the rat, erosion of the molar teeth can be detected after the consumption of 10 ml of acid solutions of the same strength used in cola beverages. A comparative test of acid erosion during a period of 6 months indicated that tomato juice had the least effect and 0.055% phosphoric acid the most. Rat teeth subjected to phosphoric acid for this period were eroded nearly to the gum line and erosion was too severe for scoring in the conventional manner. Human teeth suspended in cola beverage or its equivalent in sucrose-phosphoric acid gradually lose calcium in the course of two weeks. The buffer capacity of the human mouth against cola beverages differs widely but is fairly consistent for a given individual. Even after a half minute's exposure some mouths cannot buffer the solution to a pH higher than 3.5, which is considered marginal for erosion. A series of tests indicates that sodium oxalate ingested with food deposits patches on the teeth but is not as effective in the prevention of erosion as oxalic acid dissolved in an acid beverage. Rhubarb juice combined with equal parts of lemon juice protects the teeth against erosion. Neither stearic nor phytic acids prevented erosion by acid beverages. Oxalate patches could not be deposited on the teeth of steers during a period of one month's feeding of sodium oxalate. No evidence of injury or stone formation was found after feeding adult dogs 100 mg of sodium oxalate daily for 15 months.