A factor to consider when trying to avoid developing cavities is diet. Children who,"graze" or snack on foods high in carbohydrates as well as drinking sugary liquids are more cavity prone. Great dental hygiene starts at home with daily brushing and flossing.
If your child is young, they'll need help to brush their teeth as their dexterity to brush properly develops. Make a plan with your child to brush their teeth at night and for your child to brush their teeth in the morning. Every 6 months, make sure your child makes it to their dental cleanings and exams.