Come to think of it, I agree. Regarding the experiment with eggs, I distinctly remember the soda laden egg being submerged in the liquid for 24/7, where as the other egg received water and toothpaste. Perhaps a more accurate and interesting experiment would be to wash the tooth with soda and every morning/ evening wash it with toothpaste? Theoretically this can still show how important brushing is, if toothpaste really helps combat the acids from cola.