What Really Causes Cavities? A Simple Guide to Tooth Decay
Cavities—also known as tooth decay—are something nearly everyone has dealt with or worried about at some point. Even with all the progress in dental care, they continue to affect kids, teens, and adults alike. But what exactly causes cavities? Let’s take a closer look at what’s going on inside your mouth.
What Are Cavities, Anyway?
To understand cavities, it helps to know how your teeth are built. The outer layer, enamel, is super hard and acts like a protective shield. Underneath that is the dentin—a bit softer—and then the pulp, which contains nerves and blood vessels. A cavity starts when the enamel begins to break down, slowly making its way deeper if not treated.
Plaque: The Silent Trouble-Maker
One of the biggest reasons people get cavities is plaque. It’s that invisible film that constantly forms on your teeth. It’s full of bacteria, and when you eat sugary or starchy foods, those bacteria get to work. They turn sugars into acids, and those acids eat away at your enamel. Over time, this can leave holes—aka cavities.
The Sugar Connection
It’s no secret that sugar is bad for your teeth. But it’s not just candy and soda—bread, pasta, and even fruit can be culprits if consumed too often without proper cleaning. The more sugar you eat (and the longer it stays on your teeth), the more fuel bacteria have to produce those harmful acids.
Acidic Foods Aren’t Off the Hook
Sugar gets most of the blame, but acids from things like citrus fruits, vinegar, or soft drinks can wear down enamel directly, too. Even healthy foods like oranges can do some damage if your teeth are frequently exposed to them. Acid weakens enamel, making it easier for bacteria to cause problems.
Skipping Brushing? Think Again.
Not brushing or flossing regularly allows plaque to stick around and harden into tartar. Once tartar builds up, it’s even harder to clean and becomes a breeding ground for more bacteria. Daily brushing and flossing, along with regular dental visits, are your best defence.
The Bacteria Behind It All
Not all bacteria are bad, but some—like Streptococcus mutans—are particularly good at turning sugar into acid. People have different kinds and amounts of bacteria in their mouths, which can affect how prone they are to decay.
When Your Mouth Is Too Dry
Saliva isn’t just there to help you swallow. It also rinses away food particles and neutralizes acids. If your mouth is often dry, whether from medication, medical conditions, or simply aging, it can make it easier for cavities to form.
Blame Your Genes (A Little)
Some people naturally have softer enamel or teeth that are more cavity-prone due to genetics. Even with perfect brushing habits, they might still deal with more decay than others. Knowing your risk can help you take extra precautions.
The Power of Fluoride
Fluoride helps rebuild enamel and makes it stronger against acid attacks. It’s found in most toothpastes and many public water supplies. Without enough fluoride, your teeth may not be as protected, especially if other risk factors are present.
Cavities don’t just happen overnight—they’re usually the result of several things coming together: bacteria, diet, brushing habits, and sometimes even genetics. The good news? Most cavities are preventable. By brushing and flossing daily, cutting back on sugary and acidic foods, and seeing your dentist regularly, you can keep your smile strong and cavity-free.
