Try to get your preschooler to drink some water after snacks and lunch. This helps rinse her mouth between brushings.
Use "disclosing" tablets (which color areas of plaque) or apply a drop of food coloring on your child's teeth with a cotton swab. That way, your child can brush away the color and see for herself what a good job of toothbrushing she does.
By age three, your child should have a full set of 20 "baby teeth." Now that your child's mouth is full of teeth, food particles easily get stuck between them. Your child (with your supervision and help) should brush with a soft-bristled toothbrush at least twice a day: after breakfast and before bedtime. An up-and-down motion will dislodge most food particles.
Choose a fluoride toothpaste that your child enjoys. Fluoride strengthens tooth enamel, which will reduce decay. If your pediatrician prescribes it, have your child take fluoride supplements once a day. (But don't automatically give your child supplements, because too much fluoride can later lead to the development of mottled adult teeth.)
At three, your child will prefer to brush her own teeth most of the time. Still, stick around to supervise and do a quick follow-up brushing if necessary. (Most children cannot manage a thorough toothbrushing until the first or second grade.)
Don't discount the importance of dental care for your preschooler's "baby teeth." If a tooth decays so much that it requires removal, this could adversely affect the positioning of your child's permanent teeth.
Alkaline and acid neutralize each other. Eating some cheese at the end of a meal will produce alkaline saliva, which can counteract (at least in part) the corrosive effect of acids produced by sugar.
An Apple A Day? No, Make It Cheese!
The best way to avoid cavities involves a combination of daily brushing and watching what your child eats. Sugar, in particular, produces an acid that removes calcium from the teeth, thereby damaging the enamel coating. This damage causes bacterial tooth decay and the formation of cavities.
So try to limit your preschooler's intake of sugar. If you never bring sugary foods and candy into your home except on special occasions, then you won't need to face the awkward situation of denying your child food that he knows you have. But if you do keep sweets in your house, try to offer only candy that your child can eat quickly and all at once. (When your child eats a lollipop or a hard candy that sits in his mouth for a long while, it's like bathing his teeth in sugar.) You might consider some sort of trade-off: Your child can have occasional candy treats, but must always brush his teeth soon afterward. Or give sweets only as part of a meal and require your preschooler to brush his teeth after eating.
Besides candy and presweetened foods, fruit juice also causes a lot of tooth decay. So after your preschooler's teeth have been brushed for the night, offer him only water to drink. Otherwise, your three-year-old's teeth will remain coated with sugar all night.