The Canadian Dental Association explains what the benefits of fluoride are to your child's (and your) developing dentition:   Fluoride is a mineral found in soil, water (both fresh and salt) and various foods. It has a positive effect on oral health by making teeth more resistant to decay. Fluoride can also prevent or even reverse tooth decay that has started.   Fluorides are used by communities as a public health measure to adjust the concentration of fluoride in drinking water to an optimum level (community water fluoridation); by individuals in the form of toothpastes, rinses, lozenges, chewable tablets, drops; and [...]