How to Prevent Tooth Decay in Children

Dental caries, also known as tooth decay, is the 10th most common and preventable disease in the world. Studies have shown that first-world countries (ie. Australia, America, UK) have over 50% of children developing dental cavities by the age of six. Overall, it affects approximately 621 million children worldwide, which is a major concern, because tooth decay is easily preventable in children.

What Causes Tooth Decay?

In a healthy child’s mouth, there is always a balance of both good and bad bacteria. However, this balance can be disturbed and bad bacteria can start to overpopulate when children are exposed to too much sugar and poor oral hygiene habits. This causes the bad bacteria to produce acid in the mouth, which ultimately results in tooth decay. It’s important to note that there is a common misconception that sugar directly attacks the teeth to cause tooth decay. But that’s not the case, it’s actually the acid that the bad bacteria produce over time, which causes tooth decay.

Sugar, time and bacteria cause tooth decay
The process of tooth decay.

You see, the bad bacteria uses sugar as an energy source to produce acid. This acid can essentially “dissolve” the tooth over time, by causing the tooth to lose its minerals. The more minerals that are lost from the tooth, the greater the chance of a cavity forming. This process is called tooth decay, and it starts long before a visible hole or cavitity can be seen in the tooth.

Different Stages of Tooth Decay

Tooth decay is a process that occurs over a period of time and goes through multiple stages and layers of the tooth. It takes time for the decay to spread from one tooth layer to another. Therefore, dentists have various ways to manage the decay, depending on the depth of the decay, and which tooth layer it has reached. 

The 3 main layers of a tooth are: enamel, dentine and the pulp.

Different Tooth Layers

1) ENAMEL = The Hard Outer Layer

  • Think of enamel as the outer shell layer of an egg because enamel is the toughest part of the tooth, but it’s also the thinnest part.
  • The acid produced by the bad bacteria attacks the outer layer of the tooth (enamel) first.
  • The primary (baby) teeth have thinner and softer enamel compared to permanent (adult) teeth. This means that decay in children can spread more quickly to the deeper layers.
  • When the decay is confined only within the enamel layer, then it’s usually not painful.
  • Most often, when the decay is only in the enamel layer, then it’s usually not detectable by parents.
  • When decay is still confined to the enamel layer, we can stop it from getting bigger by using remineralisation techniques and improving oral hygiene.

2) DENTINE = The Secondary Softer Layer

  • The second layer of the tooth is called dentine, and it makes up the bulk of the tooth.
  • Dentine is much softer than the enamel, meaning the decay spreads a lot faster when it reaches the dentine layer.
  • Once the decay reaches the dentine, it’s likely that it has created a physical hole. However, but we cannot always see this hole. This is because sometimes decay might start in between children’s teeth, and it can only be picked up on an x-ray.
  • Unfortunately, decay in the dentine layer might cause mild to moderate tooth sensitivity to hot/cold/sweet food and drinks.
  • Decay which has reached the dentine layer cannot be arrested, therefore, it needs to be repaired by a dentist – with a restoration (filling) or crown.
A cavity that started between the teeth

3) PULP = The Third, and Softest Layer

  • Similar to the soft yolk of an egg, the pulp is deep in the centre of the tooth.
  • As the decay goes deeper, it enters the third layer, the pulp. During this stage, a majority of the children will complain of severe pain from hot foods/drinks, or pain during the night and sometimes even spontaneously. A small portion of children won’t feel any pain, but the infection has the ability to spread and flare up spontaneously.
  • Sometimes, infected teeth can present with an abscess (a pimple), or facial swellings. If that is the case, your child requires urgent dental assessment. When the facial swelling can be seen outside of the child’s mouth, it is a sign that the infection is starting to spread through the body. This is a medical emergency and if you are unable to get in contact with your dentist, you should seek urgent emergency medical/dental care.
  • Decay that has spread to the pulp requires immediate treatment with a dentist – usually some form of pulp therapy (procedures similar to a root canal) + crown, or tooth extraction.
my child has a toothache

Can You Reverse Tooth Decay?

The short answer is, YES, we can reverse tooth decay if we catch the decay early and it’s still within the first, enamel layer. You see, tooth decay is an ongoing process, and a constant balance between “demineralisation” and “remineralisation”, meaning your teeth are constantly losing minerals, but also gaining minerals.

Demineralisation: this is when minerals are lost from the tooth, which favours the formation of a cavity. Some habits that encourage demineralisation are:

  • Snacking on sugar-containing foods (fermentable carbohydrates) throughout the day.
  • Poor oral hygiene habits, resulting in bad bacteria overpopulating in the dental plaque.

Remineralisation: this is when the minerals are put back into the tooth, encouraging tooth repair. Some habits that encourage remineralisation are:

  • Using a fluoridated toothpaste.
  • Staying hydrated, so your child’s mouth has a healthy amount of saliva to provide calcium and phosphate to the teeth.
demineralisation and remineralisation in tooth decay for children.
Our goal is to focus on remineralisation, and avoid bad habits which cause demineralisation & tooth decay.

Reverse Tooth Decay with Good Oral Hygiene

Regularly removing bad bacteria is important, so they don’t get enough time to produce acid and attack tooth enamel. This is best achieved by brushing your little one’s teeth with fluoridated toothpaste twice daily and flossing once daily. Flossing is to reach the areas between our teeth and gums that the toothbrush bristles cannot physically reach.

Reverse Tooth Decay with an Improved Diet

Reducing the frequency of fermentable carbohydrates (sugary foods and drinks) is one of the most important ways to reduce the risk of developing dental decay. Every time your child is exposed to sugar, an acidic environment is created in the mouth, which can cause decay. Thus, it’s best if you minimize your child’s snacking habits in between meals. But if you do decide to give them some snacks, then avoid sugary treats like fruit juices, cookies, chocolates. Instead, give your child healthy snacks like cheese & crackers, nuts, raw fruits or vegetables. Just be cautious about hidden sugars in healthy foods, if you want to read more on this topic and get tips from a dietitian, click here.

healthy snacks for children to prevent tooth decay

Reverse Tooth Decay with Fluoride

The use of fluoridated toothpaste (the appropriate type and concentration as recommended by your paediatric dentist) enhances the chance of enamel remineralisation to protect teeth against dental decay. Thus, this is the simplest and easiest way to make the most of the benefits of fluoride at home.

Lastly, Avoid Dental Decay by Regularly Visiting a Dentist

It’s best for your child to visit a dentist as soon as you see the first baby tooth coming in. Some children are more at risk of developing dental decay due to poor oral hygiene, diet, genetics, certain medical conditions. Therefore, after your first dental visit, your dentist will recommend how often your child should see a dentist after establishing your child’s risk factors. Having regular dental appointments helps your child maintain good oral health habits, prevents dental decay and dental trauma in the long run.

Take-Home Message

  • Tooth decay is an incredibly common disease of childhood. Even in first-world countries, over 50% of children have dental decay.
  • Tooth decay occurs when demineralisation of the teeth is greater than remineralisation. 
  • Dentists can use more preventative and conservative options to manage tooth decay if it’s detected early.
  • As with any disease, an early prevention-focused approach is better than waiting until there are signs of pain and/or infection. Therefore, it’s best if your child regularly sees a dentist.

Written by: Dr. Nandika Manchanda (Specialist Paediatric Dentist)


Do & Spencer. Oral Health of Australian Children. The National Child Oral Health Study 2012-14. University of Adelaide Press; 2016. 

Featherstone. Dental caries: a dynamic disease process. Australian dental journal. 2008 Sep; 53(3):286-91.

Harris et al. Risk factors for dental caries in young children: a systematic review of the literature. Community dental health. 2004 Mar; 21(1):71-85.

Kassebaum et al. “Global burden of untreated caries: a systematic review and metaregression.”  Journal of dental research 2015; 94 (5):650-658.

Nandika Manchanda

Hello, my name is Nandika and I am a specialist Paediatric Dentist in Western Australia. My passion is giving children a happy and healthy smile! I am an active member of the society, and love to make time outside of clinical hours to present paediatric oral health education through seminars all over Australia. I work primarily in specialist private practice, but I also provide after-hours emergency care through the Perth Children’s Hospital. Outside of paediatric dentistry I enjoy makeup, baking, family time and all things Beyoncé. I will also find any excuse to get out of dental scrubs and relax in my activewear.

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How to Prevent Tooth Decay in Children
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