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Teeth Hurt When Eating Sweets But No Cavities

If your teeth hurt when eating sweets but you don't have cavities, it can be due to dentin hypersensitivity or demineralization of teeth. Those are the two reasons which our dentists in Long Island City can think of as to why you're having discomfort.

Table of contents:

Eating sweets can trigger dentin hypersensitivity

Even without a cavity, eating sweets can trigger dentin hypersensitivity because the acidity or low pH of the food can irritate the tooth nerve.

This can be explained by the hydrodynamic theory which was first proposed by Brannstorm. The theory states that stimuli cause fluid movements within the dentinal tubules, which can be sensed by receptors. Depending on the type of stimulus, the fluids will flow either towards the nerve or away from it.

hydrodynamic theory schematic diagram
Credit: Ji won Kim and Joo-Cheol Park

Direction of fluid movements:

  • Away from the nerve. Sweets, Cooling, drying, evaporation, and hypertonic chemical stimuli such as teeth whitening.

  • Towards the nerve. Heat and probing.

Essentially what happens when you eat sweets is the fluids within the dentinal tubules get pulled away from the nerve. The receptors sense it and it triggers a sensitivity signal. In other words, you will experience an OUCH.


Sweets can cause teeth to demineralize

The sensitivity that you're feeling from eating sweet treats could also be the result of your teeth demineralizing. This is the process where your teeth are losing minerals and dissolving due to the acidity of sweet foods.

demineralization remineralization of teeth
Credit: Sangi Co

Your teeth are hurting because the acid from sweets are dissolving the minerals from the surface of your enamel. Doesn't it already hurt just hearing those words?!

Why does the enamel demineralize?

Your enamel is predominantly (97%) composed of the mineral hydroxyapatite [Ca10(PO4)6(OH)2]. We can break it down further into its individual mineral components, calcium and phosphate.

If you recall the "Got Milk?" campaign from the early 1990s, it centered around drinking milk to get enough calcium. The entire premise was that the mineral was important for building strong bones and teeth.

Now that you understand your tooth is practically made of the minerals calcium and phosphate, demineralization is not good. As its name implies, you're practically losing calcium from your teeth when this process occurs. Your teeth are weakening since they're becoming calcium deficient.

The entire demineralization process occurs whenever the pH in the mouth drops below the critical pH level of 5.5; That is the threshold for when hydroxyapatite starts to dissolve. Yes, hydroxyapatite is acid soluble but not water soluble which is why it stays intact in neutral saliva.

Do sweets really have acids in them?

Sweets are definitely acidic because they will lower the pH of your mouth when you consume them. The definition of an acidic substance is one which has a low pH.

As an example, undiluted orange juice has a pH of 3.9 which is in the acidic range and also below the critical pH of hydroxyapatite. Yes, what you're thinking is correct. If you drink orange juice it will dissolve your enamel.

Candy chemistry
Credit: ScienceWorld

The image above shows a couple of candies and various foods and where they fall on the pH scale. As you can see candies, sodas, lemon juice, and battery acid are all in the acidic range. The worst part is that they're all below the critical pH level of enamel.

How acids dissolve the enamel

Acids have a high concentration of H+ ions, which pull the phosphates and calciums out of the tooth. The H+ specifically interacts with the phosphates (PO43-) to form various hydrogen phosphates which buffer the oral environment.

Phosphate buffering system in saliva
Credit: Crest

Since the minerals are being pulled out of the tooth, the tooth is losing minerals and thus called demineralization.

An interesting concept that we would like to present to you is that your teeth serve as sacrificial pawns. Your body prioritizes keeping the mouth in a neutral pH and will sacrifice your teeth in order to draw phosphates out of it to buffer the acid.

Significance of demineralization

Just to drive the point home, you should be concerned about demineralization of teeth because your teeth are weakening. In fact, it is the precursor to tooth decay. You can even consider it as a pre-cavity which often has a white spot appearance.

white spot on front tooth
white spot on front tooth

If you permit the teeth to continually demineralize, it will eventually lead to a cavitation in the tooth. Once the tooth becomes cavitated, it will be officially considered a cavity since there is a hole in it.

cavity on chewing surface of molar
cavity on chewing surface of molar

In case you were wondering why this is not considered a cavity is because it is subclinical. That implies that the symptoms are not really clinically detectable. For a cavity to be considered one, it needs to have a visual hole or can be seen on dental x-rays.

Since demineralization is just the beginning, it doesn't show up on the x-ray and that is why your dentist told you that there was no cavity. However what that means is since you're feeling sensitivity when you eat sweets, a cavity is trying to form!


How to reduce sweet sensitivity

Despite there not being an actual "cavity" yet, your tooth is experiencing unfavorable conditions. You shouldn't ignore it because it can get worse and we don't want you to be in pain.

How to deal with sweet sensitivity:

  • Minimize the intake of sweets.

  • Use a desensitizing toothpaste.

  • Use a remineralizing toothpaste.

Decrease sweets consumption

If eating sweets cause your teeth to feel sensitive, it may be a sign that you should decrease the consumption of them. Sweet treats don't provide the same nutrition value as whole foods such as leafy green vegetables.

You should try to replace some of that sugar with more vegetable intake instead! It'll keep your teeth and your body healthier. Aside from that don't forget that having too much sugar can potentially lead to diabetes.

We believe it is a win-win situation if you just cut sugar out of your diet. Your body and your teeth will thank you in the future.

Use desensitizing toothpaste

If your teeth are feeling sensitive due to dentinal hypersensitivity, one way to treat it at home is with desensitizing toothpaste. There is a particular ingredient within some sensitive toothpastes called potassium nitrate, which can desensitize the nerve directly.

What potassium nitrate essentially does is render the nerve unexcitable so that it does not fire signals. Despite the tooth still being exposed to the sweets stimuli, your body just won't react to it.

However you should be aware that you must use the toothpaste for at least 2 weeks for you to see results. After that you need to continue using it so that the effects do not dissipate. The desensitizing effect should also increase all the way up to the 12th week as well.

Remineralize teeth with toothpaste

Fortunately demineralized teeth can be reversed by remineralizing them. Since your enamel is losing minerals, all you have to do is add the minerals back in.

Toothpaste remineralization agents:

  • Fluoride

  • Nano-hydroxyapatite

How fluoride strengthens your teeth

Fluoride can help your teeth via multiple mechanisms and all you need to do is brush with it twice a day everyday.

  • Inhibition of demineralization. Fluoride ions replace the hydroxyl group and transforms hydroxyapatite into fluorapatite. It becomes more stable, harder, and less soluble.

  • Enhancement of remineralization. Fluoride is more readily taken up by decayed enamel than non-decayed. It pulls in calcium and phosphates to initiate remineralization.

  • Inhibition of bacterial activity in the plaque. Fluoride effectively inhibits the carbohydrate metabolism of acidogenic oral bacteria.

Demineralization with fluoride present
Credit: Crest

Nano-hydroxyapatite can repair your teeth

Toothpaste with nano-hydroxyapatite are highly biocompatible because it is biomimetic. If you needed further convincing, look no further than the fact that your teeth are made of hydroxyapatite.

  • Repairs demineralized sections of tooth. The nano-hydroxyapatite molecule inserts itself into the damaged parts to fill in all of the voids.

  • Serves as a reservoir for calcium and phosphate.

  • Creates a "sacrificial layer" of hydroxyapatite over the enamel. This layer receives the brunt of the acid attack first and dissolves before the enamel does. When it dissolves, it releases calcium and phosphate which can be used to remineralize the tooth and also buffer the oral environment.

tooth remineralization schema with hydroxyapatite
Credit: Lijie Chen, Suma Al-Bayatee, Zohaib Khurshid, Amin Shavandi, Paul Brunton and Jithendra Ratnayake


Aside from cavities, your teeth can also feel sensitive after eating sweets if you have dentinal hypersensitivity or demineralized enamel. Despite not being cavities, it doesn't mean that you should ignore them because it can get worse or even lead to decay.

What you should do is immediately reduce the sweets intake. Then you should also use a desensitizing and remineralizing toothpaste. That should help your teeth repair itself and get stronger. Once it does, your teeth should stop hurting when you eat sweets.



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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