Clinically reviewed by Dr Ellie Nadian, Specialist Paediatric Dentist.
Yes, sometimes, tooth decay in picky eaters can happen even when teeth are brushed twice a day, because decay is driven as much by how often sugars and starches reach the teeth as by how well those teeth are cleaned. Yes, twice a day, every day! That is what one of our Brisbane mums told us when we asked her about her son's brushing habits and oral care routine. The boy still ended up having several cavities in his teeth, explains Dr Ellie Nadian. The hardest part for this mother was not the fact that her child needed treatment. It was wondering what she had done wrong. To be honest, nothing, as it turned out. A check-up twelve months earlier had shown no decay at all. Then X-rays found decay close to the nerve in both lower baby molars. Her son is a fussy eater who avoids certain textures, and at daycare, he would only accept fruit, crackers and breadsticks, grazing on them throughout the day. Nothing she did with the toothbrush was wrong. But, if brushing was not the problem, what was?
Why Brushing Twice A Day Was Not Enough!
Brushing twice a day was not enough in his case because brushing was never the problem. According to our Brisbane paediatric dentist, two things worked together in this boy's mouth. First, he grazed. With his narrow range of accepted foods, he would nibble fruit, crackers and breadsticks across the whole daycare day, and every time he ate, the sugars and starches fed the bacteria that make acid. A mouth under that many small acid attacks never gets the quiet stretches it needs for saliva to repair the enamel. Second, the decay took hold between the back teeth, in the tight contact points that a toothbrush cannot reach and floss can. So the brushing was doing its job on every surface it could touch. What it could not do was undo the effect of constant snacking or clean the surfaces where the cavities were actually forming. Careful brushing and cavities can sit side by side, because frequent eating and the spots between the teeth are working away where the brush has no influence.
What Really Causes Tooth Decay In Fussy Eaters
Fussy eating does not rot teeth on its own. What does the damage is the pattern that often comes with it: a small handful of accepted foods, eaten little and often, all day long. When a child will only accept a narrow range of snacks, those snacks tend to be the exact ones teeth like least, and they get eaten again and again. Here are the real reasons cavities take hold.
- Constant Snacking: Every time a child eats, the bacteria in plaque turn the food into acid, and the tooth surface loses a little mineral until saliva repairs it. A child who grazes across the whole day keeps that acid running with almost no breaks. What we see in our own chair is the same pattern. A child who eats continuously never gives the mouth a rest. In a large study of preschool children, those who snacked all day instead of eating proper meals were more than twice as likely to have decay.
- Beige, Crunchy Foods: Crackers, breadsticks and dry biscuits do not taste sweet, so they seem harmless. They are not. Tooth decay happens when foods containing carbohydrates, which means sugars and starches, are left on the teeth, and bacteria change them into acids. Starchy snacks count just like sugary ones.
- Foods That Cling: The soft, pasty foods many fussy eaters prefer stick in the grooves and between the teeth, where they sit and feed bacteria long after the snack is finished. The longer food stays on a tooth, the longer the acid attack lasts.
- Fruit All Day: Fruit is genuinely good for children, and no one should stop offering it. The catch is frequency. Eaten in small amounts across a whole day, fruit keeps the mouth acidic and never lets it recover. It is not the fruit that is the problem. It is the all-day part.
- No Rest For Saliva: Saliva is the mouth's own repair system. It puts minerals back into the enamel and, together with fluoride, can stop or even reverse early decay. But it needs uninterrupted stretches to do this. Grazing takes those stretches away.
- The Gaps Between The Teeth: Once the back baby teeth grow in and sit tightly together, a toothbrush can no longer reach the surfaces between them. In a grazing child, those hidden surfaces are exactly where decay tends to start. That is what we saw in this little boy. Every cavity sat on a surface between the teeth, while his front teeth stayed perfectly clear, which is why the decay could take hold even though his brushing looked perfect.
What Parents Can Change Without Fighting Their Child At Every Meal
When your child finishes brushing at night, teach them to spit out the toothpaste instead of rinsing with water, because the leftover fluoride keeps protecting the teeth overnight and helps make them stronger. Once the back teeth grow in and sit against each other, a brush can no longer clean between them, and that is exactly where this little boy's cavities started, so clean those gaps with a floss pick, which is easier to manage whether you are doing it for your child or they are learning to do it themselves. Give plain water between snacks, since it is the best drink for teeth, carrying fluoride and adding no sugar or acid for bacteria to feed on. And let your dentist share the load, because fluoride painted straight onto the teeth takes only seconds, and closer check-ups pick up anything new while it is still small and easy to treat.
Why There Was No Pain, No Flinching, And No Warning
Tooth decay causes no pain until it is deep, so a comfortable child is not proof of a healthy mouth. Three things kept this hidden.
Decay between the teeth cannot be seen. It sits below the contact point, under intact enamel, out of sight from every angle a parent can look. It only appears on an X-ray.
It develops quietly, and faster than parents expect. In some cases, decay between baby teeth may go from nothing to deep in about a year, which is exactly what happened here. A clear check-up in June, decay close to the nerve twelve months later. Nothing was missed. The decay simply had not arrived yet.
Pain arrives last, not first. Nerves are only irritated once decay is deep. This little boy reported no pain and did not flinch when his teeth were brushed, and yet both lower molars had decay close to the nerve. And a young child often cannot tell you what a mild toothache feels like anyway. They may not have the words, or they may not connect the ache to a tooth at all.
So the absence of complaints is not reassurance. It is simply the stage before the complaints start.
Why Treatment Under General Anaesthesia?
Sleep dentistry for kids through general anaesthesia was recommended because of the amount of treatment this child needed and the child's age, not because he was badly behaved.
Both lower baby molars had decay sitting close to the nerve, meaning each might need baby nerve treatment before being covered with a stainless steel crown. Several other baby molars needed crowns for smaller areas of decay. A canine needed a filling. If either lower molar could not be saved, a space maintainer would be required. That is a long list of procedures across both sides of the mouth, upper and lower, at four years of age.
No four-year-old can sit still, mouth open, for that. Attempting it awake would mean multiple appointments, local anaesthetic each time, a child who becomes progressively more frightened, and a real risk that the work is never finished. Under general anaesthesia, the entire plan is completed in one visit, in a hospital, with no memory of it afterwards.
When Our Paediatric Dentists Consider Sleep Dentistry For Kids
- Extent of Treatment: When the plan is too long to complete comfortably in the chair, particularly when it spans several quadrants of the mouth.
- Very Young Age: When a child is too young to understand instructions or to cooperate for lengthy procedures.
- Complex Procedures: When nerve treatment, crowns, extractions or space maintainers are involved rather than a single small filling.
- Dental Anxiety or Previous Difficult Experiences: When fear has become a barrier to any treatment at all.
- Additional Needs: When sensory sensitivity, disability or a medical condition makes awake treatment distressing or unsafe.
- Pain or Infection Requiring Prompt Care: When waiting for a child to grow into cooperation is not clinically reasonable.
We never choose general anaesthesia because it is easier. We opt for it when it is the option that lets your child receive complete, safe care in a single sitting, and it is always discussed with parents and caregivers alongside its risks, its costs, and the alternatives.
Medical Disclaimer
This article is general information only. It is not dental or medical advice, and it does not replace an examination by a registered dental practitioner. The case described is one child's experience. Every child is different, and decay risk, treatment options and preventive care should always be assessed individually. Do not delay seeking professional advice because of something you have read here. If your child has dental pain, swelling or an injury, contact a dentist promptly. In an emergency, call 000.
Published July 2026. Next review July 2027.
Gentle, Friendly Dental Care For Brisbane Kids
If your child struggles with eating habits, brushing, or the dentist itself, that is worth telling us before the appointment. We can plan around it. Decay between the back teeth does not show itself until it is deep, so a proper look with X-rays is the only way to know what is really there. Call us on (07) 3343 4880 and tell us what your child needs.
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