Yes! Tooth decay is indeed contagious. Because there is bacteria in the tooth decay, it can be passed between people, similar to a bad cold.
Sugar is a big culprit for causing cavities, but they're also caused by certain types of bacteria. These bacterias release acids that break down the hard enamel on the outside of the teeth causing holes, better known as cavities. This bacteria can easily be passed by kissing, sharing food or even sharing silverware.
Another interesting fact, children are not just born with cavities. More often than not, cavities are passed to them from their parents or care givers. As long as the mom or dad have good oral health, their children should have good oral health too.
There are ways to avoid passing cavities from one to another, for example, if you drop a pacifier, do not put it in your mouth to clean it off and then place it in your child's mouth. Rather go to a restroom to clean it. A few more ways include avoiding sharing utensils, avoid kissing baby's lips, not sharing tooth brushes or even avoid pre-chewing food for youngsters if you do not have proper utensils to prepare it.
The best way to avoid cavities is by practicing good oral health. Brushing and flossing at least two times a day, and if you eat more acidic food adding an extra brushing afterward wouldn't hurt. Keep these tips in mind to help your children practice good oral health too!