Chocolate has been unfairly accused of causing tooth decay, but it is no worse than any other carbohydrate which leads to acid formulation and a decrease in pH in the mouth.
Chocolate is less cariogenic than many starchy foods, since chocolate can be dissolved in the mouth and removed from the mouth rapidly. The Cocoa bean does not contain a high proportion of carbohydrate which will ferment to produce acids. Cocoa is rich in tannins and other substances which studies indicate may play a role in reducing plaque formation.