You may be drinking these drinks that corrode your teeth every day! (Not just Coke)

In the hot summer, a bottle of iced cola is a refreshing feeling! If you were to vote for the drinks that go best with summer, the top few would be: carbonated drinks, lemonade, freshly squeezed juice, iced tea, and iced coffee.

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But it should be noted that when drinking these drinks, we also need to pay attention to our teeth. Because some drinks will corrode the hard outer shell of teeth unknowingly, increasing the risk of caries (tooth decay) and acid erosion.

How do acidic drinks corrode your teeth?

Enamel is the first line of defense for teeth and the hardest outer shell on the surface of teeth. It is composed of 95% to 97% inorganic matter (mainly hydroxyapatite containing calcium and phosphorus) and a small amount of water and organic matter.

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Enamel demineralization is the first step in tooth destruction. Any factors that may cause enamel demineralization will increase the risk of caries and erosion.

Friends who have studied chemistry know that calcium phosphate inorganic crystals are hard, wear-resistant and durable, but their natural enemy is acid! Acid can easily dissolve these hydroxyapatite crystals, causing demineralization of the enamel surface, enlarged pores, reduced hardness, causing the enamel itself to become thinner and less, and can also open up channels for bacteria to invade, increasing the risk of caries.

However, our oral defense mechanism is not vegetarian, and has certain self-correction and repair functions. Teeth are immersed in saliva for a long time, and the saliva contains a large amount of calcium and phosphorus ions (and the concentration is often higher than the tooth surface), which can be deposited on the tooth surface at any time to re-form new hydroxyapatite, making up for the calcium and phosphorus loss caused by previous demineralization, and forming a dynamic balance.

This dynamic balance has a balance point, which is the critical pH value (about 5.5). Once the balance is broken, irreversible calcium and phosphorus loss will occur. When the oral pH value is greater than 5.5, the deposition of calcium and phosphorus is greater than the loss, and the enamel surface will be repaired; when the oral pH value is less than 5.5, the rate of calcium and phosphorus loss on the tooth surface is greater than the rate of remineralization, and the enamel surface will demineralize. The lower the pH value, the more severe the degree of enamel demineralization and dissolution will be! Continuous enamel demineralization may cause two results: (1) caries (oral pH 4.0~4.5); (2) erosion (oral pH 2.5~4.0). Caries can cause cavities and damage to teeth, and in severe cases, it can develop into pulpitis and apical periodontitis, causing severe pain and loss of tooth function; while erosion can cause the entire tooth enamel shell to be dissolved and thinned, the tooth volume continues to decrease, and the ability to protect dentin and pulp is reduced.

Tooth enamel demineralization (caries) Source: Case study of Dr. Wang Yu from Zhuozheng Medical

Once tooth enamel is lost, it cannot be regenerated. Severe erosion can reduce the chewing function of the entire oral cavity, reduce the vertical distance of the bite, and even cause problems with the temporomandibular joint. Acidic beverages usually refer to beverages with a pH value of less than 4.5. Many of the drinks that everyone likes in the summer are actually acidic beverages. Combined with the critical pH value (5.5) we mentioned earlier, when these beverages come into contact with the tooth surface, they will cause temporary enamel demineralization, and the lower the pH value, the more severe the demineralization! Especially acidic beverages between pH2.0 and 4.0, which can directly lead to the occurrence of erosion. In addition, in addition to being acidic in themselves, many beverages also add sugar (especially white sugar). These sugars are easily decomposed by dental caries bacteria to produce organic acids, further aggravating tooth surface demineralization, causing a double blow! Typical products include traditional carbonated beverages, sugar-added fruit juice drinks, etc. Therefore, long-term and high-frequency drinking of acidic beverages will cause great damage to teeth!

Image source: self-made by the author

Which beverage is most harmful to your teeth?

Earlier we learned that the lower the pH value of the beverage, the more severe the demineralization of the tooth surface, and the higher the risk of erosion and caries.

As can be seen from the pH values ​​in the list below, carbonated drinks are still the most harmful to teeth (the lowest pH value and contain a lot of sugar), followed by various fruit juices and fruit juice drinks. Apple cider vinegar, iced black tea, grape juice and orange juice are also quite harmful.

Although pure lemon juice also has a low pH value, it is usually diluted with water, so the actual acid-etching effect is not that great.

In addition, although beer is not sweet, it is acidic, and drinking a lot of it may also harm tooth enamel; watermelon juice is the best among fresh fruit juices; coffee, yogurt, sports drinks, etc. are weakly acidic and have little effect on teeth.

Of course, the most encouraged drinks are purified water (or boiled water), tea (or sugar-free tea drinks), milk, soda water, etc.

How to drink less

Damage to teeth?

If you really want to enjoy the pleasure brought by beverages, we can reduce their erosion of tooth enamel in the following ways when drinking these acidic beverages:

1. Use a straw to drink to reduce the contact between the acid in the drink and the tooth surface;

2. Reduce the frequency of drinking to avoid repeated immersion of teeth in an acidic environment, providing time for saliva to buffer alkalinity and remineralize;

3. Rinse your mouth after drinking (with purified water or tap water), or drink some purified water or soda water to reduce the acidic substances remaining in your mouth;

4. It is recommended to drink between meals or within 2 hours after meals, so that the pH value in the mouth decreases when food is digested. Try to avoid drinking between meals and before going to bed.

5. Brush your teeth half an hour after drinking acidic beverages and use fluoride toothpaste to promote remineralization;

6. Pure freshly squeezed juice can be added with water to reduce the acid concentration before drinking;

7. You can add pure milk when drinking coffee. The protein and calcium in milk can "neutralize" the acid in coffee and reduce the deposition of pigments on the tooth surface;

8. Keep your teeth clean, brush your teeth in the morning and evening, rinse your mouth after meals, and use dental floss. This is very important!

The acid in beverages alone will not cause tooth enamel demineralization to form cavities. It also requires the subsequent invasion of cariogenic bacteria and the continuous metabolism to produce new acids to destroy the tooth structure and form cavities. In addition, the plaque attached to the tooth surface will block the contact between saliva and the demineralized tooth surface, making it impossible for saliva to remineralize. Therefore, cleaning the tooth surface and controlling the plaque on the tooth surface are the fundamentals of preventing tooth decay.

There are thousands of delicious drinks, but think about your teeth. I hope that after reading this article, you can choose and drink the right drinks from the perspective of protecting your teeth!

Planning and production

Author: Zhao Hechuan, Dentist of Zhuozheng Medical

Review丨Zhang Yu, researcher/PhD, Chinese Center for Disease Control and Prevention, national health science expert