Processed sugar and potato starch are the primary cause of tooth decay and neither of these are a natural part of a monkey’s diet. You may have heard that eating an apple is a good alternative to a toothbrush in an emergency, and while we don’t advise you to switch to apple toothpaste there is some truth in that.
Fruits and vegetables are made of tough carbohydrates like cellulose, which are long chains of starchy material. The fibres in these foods act like natural toothbrush fibres, just like when bits of celery gets stuck in your teeth. This, along with bacteria-fighting saliva, helps keep monkey teeth squeaky clean, although might not do wonders for their breath.
Image from flickr.com/photos/dice-kt