Causes of Sensitive Teeth: From Brushing Habits to Gum Disease and Post-Treatment Sensitivity
Teeth feel sensitive because dentin is exposed, and dentin can be exposed in several ways: brushing wear, excessive bite force, acid erosion, gum disease and gum recession, and temporary sensitivity right after dental treatment. Depending on the cause, a change of habits may be enough, or gum treatment or a filling may be needed. Cavities and cracked teeth can also cause sensitivity, so it is safest to have the cause confirmed at a dental examination.
Key facts
| Main causes listed by the KDCA | Incorrect brushing, clenching and grinding, acidic food and acid reflux, periodontal disease, temporary sensitivity after treatment, and gum recession with aging (source: Korea Disease Control and Prevention Agency (KDCA, 질병관리청) National Health Information Portal) |
|---|---|
| Natural exposure | In about 10% of teeth, the cementum and enamel do not meet, so dentin is exposed from the start (source: KDCA National Health Information Portal) |
| Periodontal disease prevalence in adults | 23.4% among those aged 19 and over (2018 Korea National Health and Nutrition Examination Survey, oral examination) (source: KDCA National Health Information Portal) |
| Tooth-neck wear and age | Cervical wear caused by brushing, chewing pressure and bad habits becomes more common with age (source: KDCA National Health Information Portal) |
| Treatments that can leave temporary sensitivity | Scaling, gum treatment, fillings, crowns, tooth whitening (source: KDCA National Health Information Portal) |
Can brushing habits make teeth sensitive?
The first cause the KDCA lists is the habit of scrubbing the toothbrush hard from side to side. The enamel at the neck of the tooth, where tooth meets gum, is thin, so scrubbing the same spot with force for a long time wears it down little by little and exposes the dentin underneath.
Wear speeds up when hard bristles, a brush head that is too large, and heavy scrubbing with a lot of toothpaste are combined. The force of the brush tends to lean to one side depending on how the handle is held, so the necks of the teeth on only one side may be worn down noticeably.
If brushing is the cause, simply easing the pressure and using short strokes can slow further wear. A deep notch will not fill in by itself, so if the sensitivity is severe, a dentist may also consider treatment to fill it.
Why do teeth become sensitive from clenching or grinding?
Grinding during sleep, or unconsciously clenching during the day, puts force on the teeth for much longer than chewing does. This force concentrates at the neck of the tooth, where the tooth flexes, leaving tiny damage in the enamel, and over time a wedge-shaped notch can form.
If your jaw feels stiff in the morning or the tooth edges are worn flat, grinding may be suspected. If the habit continues, even a filled notch tends to come loose again, so dentists address the habit that causes it as well. Check from time to time during the day whether your upper and lower teeth are touching, and if they are, practice keeping the lips closed but the teeth slightly apart. Night grinding is hard to notice yourself, and it is often first found through a family member or a dental checkup.
How do acidic foods and acid reflux affect teeth?
Highly acidic foods such as carbonated drinks, sports drinks, sour fruit and vinegar drinks dissolve minerals on the enamel surface. This is called erosion, and sipping a little at a time, rather than drinking a lot at once, lengthens the time acid stays on the teeth. Holding an acidic drink in the mouth or drinking one before bed also increases erosion.
The same happens when stomach acid rises into the mouth, as in reflux esophagitis, or when vomiting is frequent. The KDCA also lists acid reflux as a cause of enamel dissolving, so if sour liquid often comes up, internal medicine causes should be examined along with the sensitive-teeth treatment.
How are gum disease and age connected to sensitivity?
When plaque and tartar build up and cause gum disease, the gums swell and then gradually recede, exposing the root surface, which has no enamel. In the 2018 Korea National Health and Nutrition Examination Survey oral examination, the prevalence of periodontal disease among adults aged 19 and over was 23.4%, and it rose sharply in those in their 50s and older.
The gradual lowering of the gums with age also increases root exposure. Sensitivity from this cause does not decrease much by changing brushing alone, so have the condition of the gums examined first and receive gum treatment as needed. If there are factors that worsen gum disease, such as smoking or diabetes, managing them is also part of reducing sensitivity.
Can another cause be hidden behind the sensitivity?
Cavities, cracked teeth, and old restorations with gaps can also cause sensitivity to cold. The KDCA explains that when diagnosing dentin hypersensitivity, these causes and temporary sensitivity right after treatment must be distinguished.
Use the clues below only as a reference for guessing the cause; the final judgment is made by examination and tests. Even with the same sensitivity, if a cavity or crack is the cause, sensitive-teeth toothpaste will not solve it, and a filling or prosthetic treatment may be needed.
- If only one tooth is unusually sensitive, a cavity or crack is possible
- A twinge when chewing may point to a cracked tooth
- Sensitivity around a filling may mean a gap in the restoration or a secondary cavity
- Sensitivity that lasts days to weeks after treatment and then fades may be temporary sensitivity
Common myths and facts
Myth: Sensitive teeth happen to everyone with age, so you can just leave them alone
Sensitive teeth are especially common in the 30s and 40s, and many causes, such as brushing habits, grinding and gum disease, can be changed. Leaving the cause alone may allow wear and gum recession to progress.
Myth: The harder you brush, the better plaque comes off and the less sensitive your teeth get
Hard sideways scrubbing is a typical cause of sensitivity listed by the KDCA. Where and in which direction you brush matters more than force.
Myth: If a tooth is sensitive, it is always a cavity
It is common for teeth to be sensitive from exposed dentin alone, without a cavity. However, the symptoms can resemble those of a cavity, so a dentist needs to tell them apart.
Frequently asked questions
Why are several teeth suddenly sensitive at once?
It may be an effect of recent scaling or whitening, frequent acidic drinks, or a change of toothbrush. If several teeth became sensitive at the same time without any particular trigger, have the gums and any grinding checked together.
Can sensitivity in just one tooth be dentin hypersensitivity?
Only one deeply notched tooth neck may be sensitive. However, when only one tooth is sensitive, a cavity or cracked tooth is also possible, so an examination is needed. Telling the dentist whether it hurts when you chew on that tooth and whether it is also sensitive to sweets helps narrow down the cause.
My teeth seem more sensitive during pregnancy or dieting.
Frequent vomiting from morning sickness or frequent acidic foods can increase erosion. Rinse your mouth with water after vomiting, and if the sensitivity continues, have the dentist check it.
What tests are done to find the cause?
The dentist touches the sensitive area with an instrument or applies ice and air to see whether the pain is reproduced, and checks for cavities, cracks and the condition of restorations. If needed, X-rays are taken to check the inside of the tooth and the bone.
If there are several causes, which should be fixed first?
If there is gum disease, gum treatment comes first, and brushing and eating habits are changed together from the start. Causes that take a long time, such as grinding, are managed in stages after consulting the dentist. If only the sensitive spot is filled while the cause is left in place, the same spot may become sensitive again or the problem may spread to neighboring teeth, so habit correction goes along with treatment.
Related topics
- Sensitive Teeth
- Cervical Tooth Wear
- Receding gums and sensitivity
- Teeth sensitive to cold water
- Causes of Toothache
- Tooth wear