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Direct Cause of Demineralization of the Enamel

The direct cause of demineralization of the enamel on teeth is from over exposure to acidic foods below the critical pH level. That means any type of food that can make your mouth acidic enough are eligible but sweets in particular exacerbate it.

White spots on teeth - demineralization
White spots on teeth - demineralization

The combination of sugar and the bacteria in plaque can amplify the demineralization process which leads to the first stage of tooth decay.

Table of contents:


Direct causes

Broadly speaking, enamel demineralization is a result of any activity which brings the oral pH below the critical level (5.5 pH). The critical pH level is the threshold for when the enamel begins to lose minerals.

Note: Definition of demineralization = loss of minerals

Common activities which reduce oral pH:

  • Consuming sweets - sugary beverages, desserts, treats, carbohydrate rich foods.

  • Acidic foods that are spicy or sour.

Out of those two reasons above, a diet high in sugar is the most common cause of demineralization of enamel. It is also the worse one because the process gets exacerbated and amplified due to oral bacteria producing acid byproducts.

Sweets and bacteria

When you eat sugar the acidity of the food will immediately transform the mouth into an acidic environment. However what makes sugar even more dangerous is the presence of oral bacteria which eat the sugar and produce additional acid.

Essentially the enamel gets hit with a double whammy by getting demineralized twice. Once by the sugar and a second time by the acid from bacteria which processes the sugar.

To make matters worse, the acid produced by bacteria is considerably more effective at demineralizing the enamel. The reason is bacteria co-aggregate into a sticky biofilm known as plaque which adheres to the enamel surface. Therefore when they produce acid, the acid would be held in direct contact with the enamel since the plaque holds it in place.

demineralization remineralization of enamel-plaque-saliva interface
Credit: Adam Hellen

You may compare that to eating acidic foods where the acids float around in the mouth. They aren't in direct contact with the enamel such as when produced by plaque.

Other acidic foods

We most commonly think of sweets which demineralize the enamel and cause cavities but the criteria is actually just pH below the critical level. All types of acidic foods which are acidic enough will possess the potential for demineralization.

Candy chemistry
Credit: ScienceWorld

Examples of acidic foods:

  • Acidic salad dressings

  • Carbonated drinks

  • Sour foods like lemons, limes, sour patch kids

  • Spicy foods like ghost peppers or carolina reapers

As long as the oral environment breaches below the threshold of a 5.5 pH, the enamel demineralization process will begin. The resting salivary pH is 6.2-7.6 which is close to neutral.


How enamel demineralizes

The enamel begins to demineralize once the oral pH drops below 5.5 which is the critical pH threshold. The acidic hydrogen ion (H+) from your food pulls the mineral phosphate (PO4-2) out of your enamel.

critical ph of hydroxyapatite and fluorapatite
Credit: Adam hellen

The enamel is composed of hydroxyapatite [Ca10(PO4)6(OH)2] which is essentially the two minerals, phosphate and calcium combined together. The phosphate brings the calcium with it when it comes out of the teeth during the process.

Since the tooth has now lost minerals, this entire process is deemed as demineralization.

Symptoms of demineralization

  • White spots - areas that are chalky opaque white looking.

  • Visible holes or pitting - visibly see damaged or missing tooth structure.

  • Tooth sensitivity - sensitive whenever you eat cold, hot, sweet, or acidic foods.

  • Toothache - pain that may be stimulated or spontaneously.

  • Surface discoloration - black or brown staining.

white spot on canine tooth
white spot on canine tooth

Reversing demineralization

The enamel demineralization process is self-limiting to an extent but you can also intentionally remineralize the teeth.

  • The mouth's phosphate buffering system helps to minimize the damage from demineralization.

  • Remineralization activities can pause and even reverse the damages.

Put another way, this is how you reverse and prevent cavities.

Phosphate buffering system

You may be surprised but as the tooth demineralizes, the oral phosphate buffering system concurrently slows down the rate of demineralization. In other words, the demineralization process inherently slows down over time.

The reason that slows down is due to our mouth's phosphate buffering system. The hydrogen ion will combine with the phosphate from the enamel and that makes the mouth less acidic.

Phosphate buffering mechanism:

  1. HPO4-2 <~> PO4-3 + H+

  2. H2PO4- <~> HPO4-2 + H+

  3. H3PO4 <~> H2PO4- + H+

Phosphate buffering system in saliva
Credit: Crest

The ultimate result is that demineralization activity will gradually slow down over time. The acidic hydrogen ions get buffered by the phosphate.

Note: Our saliva naturally contains phosphates which will begin buffering the acids as soon as the mouth pH starts declining. However the acidic foods we eat usually overwhelm the buffering system and we require help from our teeth to stop the acid.

Teeth serve as a phosphate reservoir

You can actually think of your teeth as a reservoir for phosphate. Whenever the saliva's buffering capacity reaches its limit, your body starts to sacrifice your teeth in order to procure more phosphate to deacidify the mouth.

Our body seems to prioritize maintaining a neutral oral environment at the expense of our teeth. We can't think of a better way to describe the situation than to think of our teeth as, "My sister's keeper". Except in this case, the teeth get kept around solely for the purpose of deacidifying the mouth!

Remineralization activities

Instead of letting your tooth minerals dissolve, you can stop and reverse the process by intentionally remineralizing them. There are things that we can actively do to limit the damage and even reverse the process by repairing the teeth.

  • Rinsing after meals. Rinsing even with water immediately after eating can wash away the acids and dilute it. Doing so will help to minimize the damage.

  • Brushing with remineralization toothpaste. Toothpastes with fluoride or hydroxyapatite can help directly remineralize the enamel by repairing them.

  • Minimize snacking. The pH in the mouth drops every time you eat, more frequent meals is more hazardous than less frequent meals.

  • Minimize acidic foods. The greater the acidity of your meals the greater the potential for demineralization. A more basic or neutral diet is less harmful for your teeth.

Partaking in the above activities can actively help you mitigate the effects of enamel demineralization. The more of it that you do the greater the effect.



The direct cause of enamel demineralization is a result of the teeth being subjected to acid exposure below the critical pH level. The most common occurrence of that is during the consumption of sugar, which is considerably more harmful than other acidic foods.

  • The sugar directly causes the enamel to dissolve since it is acidic.

  • The bacteria in plaque will process the sugar and produce additional acid which can further dissolve the enamel.

If your teeth are losing minerals, you may want to stop the process and reverse it by attempting to remineralize them. If you need help, you can book a preventative dentistry appointment with one of our dentists in Long Island City.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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