How to prevent cavities in children
Tooth decay is one of the most common chronic conditions in childhood, and much of it can be prevented with daily habits.
Brush your child's teeth twice a day with fluoride toothpaste: a rice-grain-sized smear under age three, a pea-sized amount from three to six. Help with brushing until they can do it well. Keep sweet foods and drinks to mealtimes, offer water between meals, and book regular checkups. Sealants and fluoride varnish add extra protection.
How cavities form in children
Bacteria in plaque feed on sugars and starches and produce acid. Each time a child eats or sips something sugary, the acid softens enamel for a while. Baby teeth have thinner enamel than adult teeth, so decay can spread quickly.
How often sugar touches the teeth matters as much as how much sugar there is. Sipping juice all morning or snacking throughout the day gives teeth little time to recover.
Brushing and flossing by age
- Under 3: brush twice a day with a smear of fluoride toothpaste the size of a grain of rice
- Ages 3 to 6: use a pea-sized amount and teach your child to spit, not swallow
- Help with brushing until about age 8; a good test is whether they can tie their own shoelaces
- Start flossing once teeth touch each other, usually the back molars
- Brush last thing at night, with nothing but water afterward
- Lift your child's lip regularly and look for white chalky spots or brown areas near the gums
Food and drink habits
- Make water the main drink between meals; plain milk is a good choice with meals
- Keep juice, pop, sports drinks and sweets to mealtimes, if at all
- Choose cheese, vegetables, plain yogurt and whole fruit for snacks
- Watch sticky foods such as dried fruit, gummies and crackers, which cling to teeth
- Don't send a child to bed with a bottle or sippy cup of milk, formula or juice
- Offer a cup instead of a bottle from around 12 months
Making brushing easier at home
Many parents find toothbrushing is the hardest part of the day. A routine helps: brush at the same times each day, in the same place, so it becomes automatic.
For toddlers, sitting on the floor with their head in your lap gives you a clear view. Let your child have a turn with the brush, then finish the job yourself. A two-minute song or timer makes the time pass faster, and brushing alongside your child shows them it's part of everyone's day.
Older children can use a sticker chart or a brushing app. Praise effort rather than perfection, and check the back teeth and the gumline, which are the spots kids miss most.
Extra protection at the dental office
Fluoride varnish is painted on the teeth in seconds and helps strengthen enamel. It's often applied at checkups for children with a higher risk of cavities.
Dental sealants are thin coatings that fill the deep grooves on the chewing surfaces of back teeth, where brushes struggle to reach. They're usually placed on permanent molars soon after they come in, around ages 6 and 12.
Regular checkups let the dentist find early changes while they can still be reversed or treated simply. At our office, children are welcome from their first birthday or within six months of their first tooth.
Frequently asked questions
Is fluoride safe for children?
Yes, when used as recommended. The right amount of toothpaste for your child's age gives protection while keeping the risk of white spots on teeth (fluorosis) low.
Can white spots on teeth be reversed?
Early white chalky spots are a sign of enamel losing minerals. With fluoride and better habits, they can sometimes harden again before becoming a cavity.
Do baby teeth with cavities need to be filled?
Often yes. Untreated decay can cause pain, infection and problems for the adult teeth underneath. The dentist will explain the options for each tooth.
Are children's checkups covered?
Most insurance plans cover children's exams and cleanings, and many children qualify for the Canadian Dental Care Plan. We can check coverage for you.
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Trusted health information
General information only; not a substitute for an exam. Reviewed by Dr. Sayeh Maralani, DDS, general dentist. Last updated 2026-11-03.
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