You have asked a really important question. Teeth should be cleaned as soon as they begin to show in the mouth. The age of eruption is quite variable and differs from child to child. I asked my colleague, Dr. Mindy Cash-Golosky at the University of Toronto, for the guidelines they offer their patients. Cleaning can be done by simply wiping the teeth with a moistened piece of gauze or a washcloth. As your baby gets more teeth, you can use a baby toothbrush with soft bristles and water only to brush all surfaces of the teeth and tongue. It’s not unusual for your baby not to want to allow this! It’s a good habit to get your child, once old enough, into brushing in the morning and evening. Many of my dental colleagues, in addition to brushing their children’s teeth, also started flossing their kids’ teeth with disposable floss wands when they were very young. Technically you only need to floss teeth when they are contacting each other, but again, good training that is started very young will eventually become a habit. As the children get older and get more dexterity, you can teach flossing with the string type, but wands are still great.
Introduce toothpaste once your children learn how to spit it out. If they cannot spit it out, there is a potential risk of swallowing the fluoride toothpaste and developing fluorosis, a weakening of the tooth that appears as tiny white streaks or specks in its mild form, or black and brown stains, or, at its most severe, pitting of the teeth. Once toothpaste is initially introduced, it should be used in very small amounts.