Sudden tooth sensitivity happens when the hard outer layer of your teeth wears down or your gums pull back from the tooth surface.
This exposes a softer layer underneath called dentin. Dentin has thousands of tiny tubes that connect straight to the tooth’s nerve.
When something hot, cold, sweet, or acidic touches these tubes, you feel a sharp, sudden pain.
About 1 in 8 adults deal with this problem.
The good news?
Most causes are treatable with help from your Calgary dentist.
Common Causes of Sudden Tooth Sensitivity
| Cause | What Happens | Common Signs |
| Enamel erosion | Acidic foods, hard brushing, or aging wear down your protective enamel | Pain with hot or cold foods and drinks |
| Gum recession | Gums pull away from teeth, exposing unprotected root surfaces | Teeth look longer, sensitivity near the gum line |
| Teeth grinding (bruxism) | Clenching or grinding wears down enamel over time | Jaw pain, headaches, worn tooth edges |
| Cracked or chipped tooth | Damage allows temperature changes and bacteria to reach the nerve | Sharp pain when biting, sensitivity to temperature |
| Tooth decay (cavity) | Decay breaks through enamel and reaches sensitive dentin | Lingering pain, visible holes or dark spots |
| Recent dental work | Fillings, crowns, or cleanings can temporarily irritate the tooth | Sensitivity that improves within 1-2 weeks |
| Teeth whitening | Whitening agents can temporarily affect enamel | Sensitivity during or shortly after whitening |
| Sinus infection | Swollen sinuses press on upper tooth nerves | Upper back teeth hurt, facial pressure |
Why Enamel Loss Leads to Sensitivity
Your teeth have three main layers. The outer layer is called enamel. It’s the hardest substance in your body. Enamel acts like a shield that protects the more sensitive parts inside your tooth.
Under the enamel sits a layer called dentin. Dentin is much softer than enamel. It contains thousands of tiny tubes called dentinal tubules. These tubes run from the outer surface of your tooth all the way to the nerve inside.
When enamel wears thin or gets damaged, dentin becomes exposed. Now those tiny tubes are open to the outside world.
When you drink something cold like ice water or eat something hot like soup, the temperature change moves fluid inside these tubes. That fluid movement triggers the nerve, and you feel a sharp zing of pain.
The same thing happens with sweet or acidic foods. Sugar and acid can enter the exposed tubes and signal the nerve. This is why people with sensitive teeth often feel pain from multiple triggers.
A regular dental check-up can catch enamel wear early, before sensitivity becomes a bigger problem.
8 Common Causes of Sudden Tooth Sensitivity
1. Enamel Erosion
Enamel can wear down over time. Several things speed up this process:
- Acidic foods and drinks like citrus fruits, tomatoes, coffee, and pop
- Brushing too hard or using a toothbrush with stiff bristles
- Using toothpaste that is too rough on your teeth
- Natural thinning that comes with age
Once enamel is gone, your body cannot grow it back. That’s why protecting what you have is so key.
2. Gum Recession
Your gums normally cover and protect the roots of your teeth. When gums pull back, they expose the root surface. Here’s the problem: tooth roots have no enamel coating. They’re covered only by a thin layer called cementum, which wears away quickly.
Gum recession can happen from:
- Gum disease (gingivitis or periodontitis)
- Brushing with too much force
- Natural gum thinning as you get older
- Using tobacco products
If you notice your teeth looking longer than before, or if you feel sensitivity right at the gum line, talk to your dentist. Periodontal care can help stop gum recession from getting worse.
3. Teeth Grinding (Bruxism)
Many Calgary residents grind their teeth without knowing it. This often happens during sleep or during times of stress. Over months and years, grinding slowly wears down enamel. You might not notice until sensitivity appears.
Signs you might be grinding include:
- Waking up with jaw pain or headaches
- Noticing flat or worn spots on your teeth
- Catching yourself clenching during the day
A custom night guard can protect your teeth while you sleep and prevent further enamel loss.
4. Cracked or Chipped Teeth
Cracks in teeth can happen from biting down on hard foods, chewing ice, or from an injury. Some cracks are visible, but others are too small to see. Even tiny cracks can cause pain because they let temperature changes and bacteria reach the nerve inside your tooth.
If you feel a sharp pain when you bite down, or if one specific tooth hurts with hot and cold, a crack might be the cause.
5. Tooth Decay (Cavities)
A cavity starts small on the outer enamel. At first, you might not feel anything. But as decay grows deeper and reaches the dentin layer, sensitivity kicks in. This is often an early warning sign that something is wrong.
Cavities that go untreated keep growing. They can eventually reach the nerve and cause serious pain or infection. If you notice lingering pain after eating or see dark spots on your teeth, schedule an appointment soon.
6. Recent Dental Work
Fillings, crowns, and professional cleanings can sometimes leave your tooth feeling sensitive for a short time. This happens because dental work can temporarily irritate the tooth’s nerve.
This type of sensitivity usually fades within one to two weeks. If it lasts longer or gets worse, let your dentist know. Persistent pain after dental work may need attention.
7. Teeth Whitening Products
Whitening treatments—whether done at a dental office or at home—can cause temporary sensitivity. The whitening agents can affect your enamel for a few days.
According to the Canadian Dental Association, talking to your dentist before starting any whitening treatment is a good idea. They can help you choose products that work best for your teeth and suggest ways to reduce sensitivity.
8. Sinus Infection
This one surprises many people. When your sinuses get swollen and inflamed, they can put pressure on the nerves of your upper teeth. The pain feels like tooth sensitivity, but the teeth themselves are fine.
If your upper back teeth hurt on both sides and you also have facial pressure, congestion, or a runny nose, a sinus infection might be the cause. The tooth pain should go away once the infection clears up.
When to See Your Calgary Dentist About Tooth Sensitivity
Not all tooth sensitivity needs a trip to the dentist right away. But some signs tell you it’s time to get professional help.
| See Your Dentist If… | Why It Matters |
| Sensitivity lasts more than 2 weeks | May point to a problem that needs treatment |
| Pain is severe or constant | Could signal infection or nerve damage |
| Only one tooth is affected | May be a crack, cavity, or decay |
| You notice visible damage | Chips or cracks need professional repair |
| Gums are red, swollen, or bleeding | Signs of gum disease |
| Over-the-counter products are not helping | Professional treatment may be needed |
Take Action for Your Sensitive Teeth
Sudden tooth sensitivity usually has a cause that your dentist can treat. The sooner you find out what’s behind the pain, the easier it is to fix. Ignoring ongoing sensitivity can let small problems turn into bigger ones.
If you’re dealing with sudden tooth sensitivity, the team at Northland Smiles Dental can find the cause and recommend the right treatment for you. Our NW Calgary dental office on Crowchild Trail, near Northland Village, serves families throughout Brentwood, Edgemont, and surrounding communities.
Ready to find relief from sensitive teeth?
- Call us: 403-286-5030
- Contact us online
- Book an appointment
Northland Smiles Dental 4600 Crowchild Trail NW, Suite 302 Calgary, AB T3A 2L6
