Our teeth are more or less built the same way – a very strong and resistant outer layer of enamel that covers more sensitive and soft inner layers. The chemical composition and thickness of enamel is, with rare exceptions due to malnutrition and genetics, also similar for everyone. So…


…why do some kids develop cavities, and others do not?


It is very important to realize that tooth decay is caused by bacteria. These bacteria live in every mouth and thus everyone can develop cavities. To understand why some kids get cavities and others do not, we need first to understand how the bacteria cause tooth decay. Here is a short, simplified explanation.


Bacteria stick to our teeth and form what we dentists call plaque. If left undisturbed, the bacteria multiply and the plaque thickens. We can remove the plaque by brushing, however moments after we are done, the plaque starts growing again.


Bacteria that cause tooth decay get energy from sugary foods. They metabolize (change) sugar into acid, which is strong enough to dissolve the outer layer of enamel. The enamel is very tough, and it takes a long time for bacteria to cause enough damage to be able to get inside the teeth. However, once they are in, the process of decay is accelerated, and a cavity starts to grow rapidly.


Our mouths have a defence mechanism that keeps these bacteria in check. Saliva contains substances that can reduce the effect of acid on teeth. Also, saliva contains calcium and fluoride ions that constantly repair the damage the bacteria have caused.


When teeth are brushed regularly and there is little to no sugar present in the mouth, the process of decay is balanced out by the effects of saliva. Cavities will not develop under these conditions. Once dental hygiene is stopped or the sugar consumption increases, the defence provided by saliva becomes insufficient and the process of decay continues.


So, what can be done to prevent tooth decay in children?


You can reduce the risk of your child developing cavities by developing good oral hygiene habits and making sure your child eats healthy, low-sugar foods.


From the moment baby teeth erupt in the mouth, they should be brushed twice a day. Choose a fluoride toothpaste that is appropriate for the age of the child. Fluoride aids the saliva in defending teeth against bacteria, making the outer layer of enamel stronger. Children should sleep with clean teeth – so make sure the teeth are brushed before they go to bed. Do not allow snacks or drinks other than water during the night.


Water should be the preferred drink for kids. Milk is also good – but it contains some sugar.


Juice should be limited to once per day since bacteria can metabolise fruit sugar. Coca cola and other sugary drinks should be entirely avoided.


Children should eat a healthy diet. Foods that are high in sugar should be avoided. Be extra cautions of sticky sweets like toffees and biscuits – they stick to teeth and provide bacteria with a constant source of sugar.


Fruits contains sugar. Fruits are healthy for kids in moderation, but excess consumption is not recommended.


Morning cereals that are high in sugar, for example Lucky Charms and Honey Nut Cheerios, should be limited to once a week or avoided entirely.


The role of dental professionals


As with other health issues, prevention and early diagnosis are important. Kids should visit the dentist regularly. Dentists can spot cavities while they are still small, identify the cause and offer advice on how to prevent tooth decay in child. We will also perform preventive treatments that reduce the risk of developing more cavities. Also, it is easier to fix a cavity while it is still small and has not yet dissolved the majority of the tooth.


Do you need advice or have a suggestion? Please leave a comment below or contact the author via email.