Why Brushing after a Meal Can be Harmful

by ALY DUTY

The American Dental Association recommends brushing at least twice a day. If you’ve grown up going to the dentist, you’ve likely heard you should brush your teeth after every meal. While this is excellent advice, it’s important to understand that it can actually be harmful to brush immediately after you eat. In this article, we’ll discuss why it’s a good idea to wait about 30 minutes before brushing after meals.


Allow Time for Your Body to Do Its Work

Saliva is a natural cleanser. It helps wash away debris, food particles, and bacteria. This is especially helpful if you didn’t drink water with your meal. Sugary drinks only compound the problem. Unless you have xerostomia – or dry mouth – your saliva will effectively clean some of the debris. This is extremely important because sugars and other foods can actually scratch the teeth surfaces – and brushing too early after a meal may only exacerbate this issue. For example, brushing too soon can actually push sugars and acids deeper into the tooth structure.

The Effect Acidic Foods Have on Enamel

Sugar isn’t the only thing that can harm the enamel. Foods that are high in citric acid – even fruit – can temporarily soften the outer layer of the teeth. If you brush while the enamel is still soft, it can damage it – and in some cases, even remove some of it, leaving your teeth permanently weakened. If these types of food are on your menu for the day, it’s beneficial to brush your teeth before you eat. That way, bacteria won’t compromise the weakened enamel. However, your saliva goes to work immediately after eating, so this helps wash away the acids. To help this process along, you can chew sugarless gum to promote saliva production.

Diet Soda

The effects of acid on enamel are well documented in a 2004 study. During this experiment, diet soda drinkers were observed for three weeks. Researchers found that there was an increase in dentin loss when participants brushed within 30 minutes of drinking the soda. Conversely, there was much less wear when people brushed 30 to 60 minutes after drinking.

Other Ways to Protect Your Enamel

In addition to waiting 30 minutes to brush after every meal, there are a few other things that can help strengthen and preserve your enamel. For example, we recommend that patients:

• Rinse their mouth out with water immediately after eating. • Use a fluoride toothpaste and a soft-bristled toothbrush. • Use an antibacterial mouthwash.
• Consider dental sealants to help protect hard-to-reach areas from bacteria.
• Talk to your dentist about topical fluoride treatments, which can actively re-mineralize enamel and make the teeth less susceptible to damage.
• Limit sugary snacks between meals.
• Be mindful of soft drink consumption. 
• Drink plenty of water throughout the day.
• Replace your toothbrush every three months.
• Visit your dentist on a regular basis.

Brushing is an essential aspect of oral healthcare, but it’s important to understand proper methods. Talk to your local dentist about brushing and flossing recommendations.