Exploring: Why do Kids Get Cavities?

This blog is for informational purposes and doesn’t establish a doctor-patient relationship. Learn more.

A question we get a lot at our office is: how did my kid get so many cavities? And why do kids get cavities in the first place?

This is a really good question! A lot of times, we feel like we’re eating a healthy diet. We’re feeding kids all their fruits and veggies. Yet, we’re still seeing cavities!

First things first – it’s not your fault your kid has cavities! They happen. How they get cavities is really one of those things that come down to understanding the science behind how cavities form, which is what we call caries etiology.

Today, we’re exploring why kids get cavities along with signs of cavities in children, what causes cavities and sharing tips on how to prevent cavities in your child. 

Let’s explore!

VIDEO: Why Do Kids Get Cavities?

What is a cavity?

Before we can get into why kids get cavities, I’ll give a short answer about what a cavity is.

A cavity is a hole that forms in a tooth. The start of a cavity is the loss of minerals from the surface of the tooth. Once the outer layer of the tooth – the enamel – is broken, the hole forms. It can be hard to stop the process and prevent the hole from getting deeper. If you’d like to learn more, here’s a video that tackles your “what is a cavity?” question head-on.

Signs of Cavities in Children

A cavity looks like a hole in a tooth, but that hole may be small at first and hard to see (which is why we wear special magnification glasses). We used to think that black indicated a cavity. In movies, the bad guys usually have gross-looking black teeth! But we now know that the most active cavities are yellow or white.

A black cavity can either mean that darkly colored food is getting stuck in the cavity or that bacteria have started dying and the cavity is changing. Other signs of a cavity might be food getting stuck in the grooves or between teeth. Eventually, food packing in between teeth can result in the gums hurting or bleeding, especially when brushing or flossing.

If you think your child might have a cavity, one of the best things to do is brush their teeth extra well. Then have them lay their head in your lap and look at the teeth with a flashlight. Cavities forming between the teeth can be hard to see without x-rays, but you might feel floss getting caught between the teeth where it used to slide freely.

So, why do kids get cavities? And how do cavities form?

Another great question is how cavities form. What actually causes cavities?

The best way I can explain it is that bacteria live on our teeth, and the acid they excrete dissolves tooth structure. Every time we eat, they eat what we eat! Then, they digest what we eat. Their poop is acid – kids love when you explain it this way, by the way! – and that acid breaks down the teeth. Any time oral pH falls below 5.5, teeth can lose minerals.

Anything that’s acidic can contribute to the breakdown and destruction of teeth. Even things like fruits that are really delicious and good for us and have lots of vitamins and nutrients can still cause cavities. That’s because fruit contains fructose which the bacteria can digest and excrete acid.

The bacteria that live in our mouths love sucrose (which is what we traditionally think of as sugar), but they are willing to eat other types of sugar like fructose and lactose.

How Snacking Contributes to Cavities in Kids

When we’re considering the options we have to reduce cavity formation, the biggest one is the duration of exposure to any fermentable carbohydrates. What that basically means is when we eat and how long we eat.

If your kid is a grazer and loves to snack on little bitty snacks all day – which so many kids do because their bodies are growing and they haven’t quite learned how to understand hunger signals – this could be a big factor. Maybe your kid likes just to eat a little bit, run, go play, and then come back and eat some more. And that’s really the worst thing they could do for their teeth.

Why? Because it’s so hard for the body ever to buffer that acid that’s being produced. While eating and for a while after eating, our bodies increase saliva production and change the type of saliva produced. Stimulated saliva, as it’s called, has higher levels of bicarbonate which helps return the mouth to an appropriate, neutral pH level.

Giving our mouth a break between eating allows our acid levels to decrease and keeps our teeth strong. If you can encourage your littles to sit down and eat at mealtimes – easy for me to say, I know it’s hard to do – and encourage them to stay away from certain snacks that produce more acid, then we can usually get back on track.

Exploring snacking and cavities. Little girl eating cereal.

How to prevent cavities in children

Dental visits 

Regular dental check-ups give us a chance to make sure that your family has a plan and hygiene routine. The goal is to prevent cavities from forming and find any areas where cavities are beginning. If we catch the start of a cavity early, we have many more options. Often, our options are minimally invasive, as well. 

Read more about when your kids should be going to the dentist.

Brushing and flossing habits

For a cavity to form all three components must come together – tooth, bacteria, and food. Brushing helps prevent cavities by addressing all three elements. Toothpaste can deliver minerals to the tooth structure making the tooth itself harder and more resistant to decay. The bristles of the brush disturb dental plaque which is a biofilm, a complex ecosystem of bacteria, and help remove food particles that are lingering in the grooves on and around teeth.  

Snacks and foods that prevent cavities

As I mentioned, snacks and foods also play an important role in your child’s oral health. The foods that prevent cavities would be veggies, nuts, cheese, and meat. The reason is that these snacks really aren’t going to contain any fermentable carbohydrates. That means acid production following eating those foods is very limited. 

But, look. It’s really easy for me to sit here and say reduce grazing, snacking, and steer them towards other choices! But it definitely makes a big difference. So if your kid is getting cavities and they’re a grazer, my number one change would be discouraging eating between meals.

You’ve got your work cut out for you! 

How to treat cavities in children

Your child has a cavity – now what? If the cavities are in baby teeth, we need to evaluate how soon that tooth will be lost before deciding appropriate treatment. If a tooth is expected to exfoliate within the year, we can typically monitor it until it falls out. But if the tooth will be in the mouth for many years or has caused an infection, we would want to fill the cavity or remove the source of the infection. Based on age and x-rays, we can identify how much time we need the baby tooth to last and what our treatment options are.

If the cavities are in permanent adult teeth, we always want to address them promptly so we can prevent further damage to the teeth your child will have for the rest of their life.

What is cavity filling? For cavities that are small, we can remove the bacteria, food debris, and infected tooth structure. Then, we can restore the tooth to its normal shape and function with a composite filling material.

For cavities that are too large or deep for a filling we would use a crown to restore the tooth. This can happen really quickly in baby teeth because they are much smaller and the nerve is much larger! Thankfully, having a crown placed for a baby tooth is very different from adult permanent crowns. Multiple appointments are required for crowns on permanent teeth, and the crown must be custom designed. But for baby teeth, we can use a standardized size and fit to place a crown in one appointment with minimal removal of tooth structure.

In our office, we use both stainless steel and zirconia. Stainless steel crowns are similar to cookware you might have in your home. One advantage of a stainless steel crown is that it can be bent and adapted to the tooth’s shape and requires less tooth structure to be removed. Zirconia crowns are ceramic crown, so they are inherently more brittle and cannot be adjusted but have the advantage of appearing tooth-colored.

If you suspect your child has cavities, the first thing to do is schedule an appointment so that we can explore what might be causing their cavities and determine our treatment options.

Expedition Pediatric Dentistry is a pediatric dentist in Bellevue, WA providing dental care for infants, children, and adolescents in Bellevue, WA. We also accommodate special needs! If you’re local, book an appointment and we can figure out the cause of your child’s cavities from our office!

Happy trails.

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