Don’t Brush Your Teeth After Eating?

Today we will talk about one of the common misconceptions by patients about brushing their teeth after eating.  There’s a lot of conversation about when to brush your teeth either before or after breakfast. Most people actually brush their teeth in the morning after eating breakfast, which is one of the worst things you could do for your teeth.

To really understand the perfect time to brush your teeth, we have to dive into basic science and understanding tooth structure. Bear with me when we talk about a little bit of the basic science because it helps you understand why I’m recommending when to brush your teeth.

The outermost layer of the tooth is called the enamel and that is the protective layer of each tooth. It’s the strongest structure in your body, which is stronger than any bone. The enamel is made of a bunch of crystalline structures that project outward from your tooth. It’s a bunch of crystal rods that project towards your mouth. These crystal rods have a bunch of minerals in them. These minerals are calcium and phosphates and they are what make the teeth so strong. What happens when you get a cavity though is these crystals that are part of the enamel start to shut off and your tooth starts to demineralize, which means the minerals of your tooth leave the tooth structure making it weaker. The crazy thing that a lot of people don’t know though is that every time you eat, you have a loss in these minerals, which is called demineralization. In about 20 to 30 minutes the minerals go back into the tooth structure and that’s called demineralization.


The lower the pH, the more acidic your mouth is. At rest, the pH of your mouth is about 6.5. Whenever you eat food, that’s acidic or sugary, this pH goes down. How low it goes is dependent on the food that you eat. Food like orange juice and energy drinks are very acidic whereas others like milk aren’t as acidic. But when the pH of your mouth goes below 5.5, this is when your tooth starts to lose the minerals that are in the enamel. This is called demineralization. If you were to brush your teeth during this time, you’re basically brushing away enamel. That’s softer than it should be.


Do you see why I recommend that you don’t brush your teeth right after eating? Your teeth are in their most vulnerable state at this time. If you’re brushing it, you’re using an abrasive toothbrush and toothpaste and scrubbing away those perfect crystal structures. But do not worry. Your teeth do remineralize over time. Your saliva in your mouth is full of these minerals, these calcium and phosphate ions. Within about 20 minutes after eating, these crystalline structures get remineralized and all the calcium and phosphate go back into the tooth. 

This is why it’s not good to be snacking throughout the day. If you snack all day long, your body can never remineralize because it’s constantly in this softer state, which makes you more prone to cavities. If you were to eat one entire cake by yourself in about 5 minutes, it’s better for your teeth than eating one slice of cake throughout the day. Although it might not be better for your body, it would be better for your teeth. Because your teeth could remineralize in about 20 minutes whereas if you constantly snack on that sugary food, it’ll never have a chance to remineralize. In about 20 minutes after eating your mouth’s ph will go above 5.5, which makes these minerals go back into the tooth structure.

do not snack

This is the point where it’s safe to go ahead and brush your teeth. This is why I always recommend that if you’re going to eat, wait for about 20 to 30 minutes and then brush your teeth. As well as using a mouth rinse, you can clean your teeth but not cause abrasive brushing on the tooth structure, which makes the crystals can stay strong. 

When you brush your teeth, be sure to brush them using fluoridated toothpaste. You might wonder what’s so important about fluoride in your teeth. The cool thing about fluoride is when it’s in your mouth, it can go into the enamel rods and make your tooth stronger. The way it does this is because do you remember when we said the pH of the mouth under 5. starts to demineralize your teeth. If you have fluoride in your tooth structure, this demineralization doesn’t occur until about 4.5 pH. This makes it so that whenever you eat, your teeth start to demineralize later and remineralize quicker, which means if you have fluoride in your tooth structure, you’re a lot less prone to cavities and you have a better chance of having optimal dental and oral hygiene.

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