Sensitive Teeth (Dentin Hypersensitivity): A Guide from Causes to Treatment and Prevention

Sensitive teeth are a short, sharp pain from cold water, cold air or brushing when dentin at the gumline or root is exposed; the medical term is dentin hypersensitivity. The sensation typically fades as soon as the stimulus is gone, and pain that lingers after the stimulus stops or starts on its own suggests inflammation of the nerve (pulp) and should be checked at a dental clinic. Mild sensitivity may ease with desensitizing toothpaste and better brushing, but depending on the cause, treatment options range from fluoride application and resin filling to gum treatment. In Korea, the Korea Disease Control and Prevention Agency (KDCA, 질병관리청) provides the guidance summarized here.

Published 2026-11-08 · Updated 2026-11-08 · DentalStatics editorial team

Key facts

Share of people affected	8 to 57% of adults are reported to experience dentin hypersensitivity (source: KDCA National Health Information Portal)
Most painful site	More than 90% of pain sites are at the tooth neck (where the tooth meets the gum) (source: KDCA National Health Information Portal)
Common age	Most common in the 30s and 40s (source: KDCA National Health Information Portal)
Co-occurrence with gum disease	Hypersensitivity is reported in 60 to 98% of people with periodontal disease (source: KDCA National Health Information Portal)
Sensitivity after scaling	Usually fades gradually over 1 to 2 weeks (source: KDCA National Health Information Portal)
Sensitivity after whitening	Usually disappears within a few days (source: KDCA National Health Information Portal)
Professional fluoride interval	Repeat application every 3 to 6 months is recommended (source: KDCA National Health Information Portal)
Health insurance for scaling	Covered once per year from January 1 to December 31 for ages 19 and over (source: National Health Insurance Service (NHIS))

Why do teeth become sensitive?

The crown of a tooth is covered by hard enamel and the root by cementum, both protecting the dentin. Dentin contains very fine tubes leading toward the nerve, so when the outer layer wears away or the gum recedes and exposes dentin, cold stimuli reach the nerve quickly.

The KDCA explains that in about 10% of teeth the cementum and enamel do not meet, so dentin is exposed from the start. This is one reason why the same brushing makes some people's teeth sensitive and not others'.

The cause of sensitive teeth is usually not a single factor but several overlapping ones. If the tooth neck is worn by hard brushing and gum disease has made the gum recede, the sensitive area is larger and the symptoms last longer.

Brushing hard with a side-to-side scrubbing motion
Force concentrated on the tooth neck from clenching and grinding
Erosion of enamel by acidic foods and drinks or stomach acid reflux
Gum disease and gum recession caused by plaque and tartar
Temporary sensitivity right after scaling, gum treatment, fillings, crowns or whitening
Gum recession with age

How are sensitive teeth different from cavities or nerve inflammation?

With hypersensitivity, pain occurs only when cold water or cold air touches the tooth and soon subsides once the stimulus is gone. By contrast, if pain lingers for a while after the cold is removed, throbs with no trigger, or keeps you awake at night, it is closer to a sign of pulpitis.

Early pulpitis can also stop hurting as soon as the stimulus ends, so it is hard to tell the two apart from symptoms alone. At the dental clinic, the dentist scratches the surface with an instrument or applies ice or air to see whether the pain is reproduced, rules out cavities, cracked teeth and gaps around restorations, and takes an X-ray if needed.

The KDCA considers that self-diagnosing sensitive teeth can worsen the condition or lead to unnecessary treatment. Taking notes on whether several teeth are evenly sensitive or just one tooth is pinpointed will help the examination.

Is sensitivity after dental treatment normal?

When scaling removes tartar, the root surface that was hidden underneath is exposed to cold stimuli and may be sensitive for a while. The KDCA advises that this sensitivity usually decreases gradually over 1 to 2 weeks.

Sensitivity after a resin filling can occur when the exposed inner part of the tooth is not completely covered by resin or the bonding is incomplete. It usually lessens over time, but if it keeps getting worse the tooth may be treated again, so it is best to tell the clinic that did the treatment. Sensitivity right after whitening usually disappears within a few days.

Teeth may also be sensitive for a while after a crown is placed or after gum treatment. If sensitivity continues beyond the expected period, becomes worse than at the start, or begins to hurt on its own, it may not be a temporary reaction and you should be examined again.

What should I change at home to reduce sensitive teeth?

Desensitizing toothpaste containing ingredients that reduce hypersensitivity can relieve mild sensitivity to some extent. If your teeth stay sensitive even after using it, it is faster to find the cause at a dental clinic than to change toothpaste.

Also change the habits that cause it. Hold the toothbrush lightly and gently brush the boundary between teeth and gums, and do not scrub hard right after having carbonated drinks or sour foods. If you grind your teeth in your sleep or clench them during the day, consult a dentist to find a way to correct it.

The head of the toothbrush should be about the size to cover one or two teeth, and replace the brush as soon as the bristles bend or fray. The KDCA recommends that adults brush at least twice a day with toothpaste containing 1,000 ppm or more of fluoride. High-concentration fluoride applied at the dental clinic is used both to prevent cavities and to reduce sensitive symptoms.

Acidic foods and drinks cause erosion that dissolves enamel, so cut back on habits such as sipping sour fruit, carbonated drinks or vinegar drinks often, and rinse your mouth with water after drinking them. Stomach acid reflux dissolves teeth in the same way, so if sour fluid often rises into your mouth, it is best to also see an internal medicine doctor.

How do dentists treat sensitive teeth?

Treatment is chosen step by step starting from mild measures, according to the severity and cause of the symptoms. The methods introduced by the KDCA are below, and if gum disease is the cause, gum treatment comes first.

Topical application of oxalate or fluoride products to the sensitive area
Fluoride varnish application with high-concentration fluoride
Dental adhesive coating (works quickly but does not last long)
Filling the worn tooth neck with composite resin (the effect lasts longer)
Laser treatment (reported effects differ greatly between studies)
Gum grafting to cover the exposed root (results are hard to predict)
Root canal treatment, considered when other methods do not help and daily life is difficult

Does health insurance cover treatment for sensitive teeth?

If gum disease is the cause of the sensitivity, health insurance can be used for scaling, the first step. Insured scaling applies once a year from January 1 to December 31 for people aged 19 and over, and if you do not have it in that year it does not carry over to the next.

Professional fluoride application is covered by health insurance for patients who have had head and neck radiation therapy, patients with Sjogren's syndrome or dry mouth, and registered persons with brain lesion, mental or autistic disabilities. For other treatments for sensitive teeth, coverage and cost differ by method, so it is best to get itemized information from the dental clinic before treatment. Even the same resin filling varies in price depending on the material and the extent, so when you get an estimate, also confirm how many teeth and which material will be used.

When should I see a dentist for sensitive teeth?

If the sensitivity stays the same even after steady use of desensitizing toothpaste, only one tooth is especially sensitive, or you have symptoms like those below, do not delay getting examined. Even without sensitivity, a checkup about once a year can catch tooth neck wear or gum recession early.

Pain lingers for a while after the cold stimulus is removed
Throbbing on its own without stimulus, or pain that worsens at night
A particular tooth stings when chewing
Gum bleeding, swelling or tooth mobility along with it
The tooth neck is visibly worn down or discolored

Detailed guides

Frequently asked questions

Can sensitive teeth go away on their own?

If the symptoms are mild, you can wait and watch. Over time more dentin may build up inside the tooth, or the exposed surface may become less responsive, so the sensitivity can lessen. However, if it stays the same or worsens after several weeks, a dentist should check whether there is another cause.

My teeth are only sensitive to cold, not hot. Does that mean no cavity?

A pattern of short sensitivity only to cold that soon subsides is common in hypersensitivity. However, an early cavity or cracked tooth can feel similar, so you cannot conclude from symptoms alone that there is no cavity. People with hypersensitivity can also react to hot, sweet or sour things.

How long should I use desensitizing toothpaste before I can tell if it works?

It varies by product, so follow the directions on the package. If the sensitivity does not decrease or even gets worse despite steady use, the problem may not be the toothpaste and it is best to be examined. Desensitizing toothpaste is a way to relieve symptoms; it does not fill a worn tooth neck or a cavity.

Do my teeth get more sensitive after scaling?

Surfaces that tartar covered are exposed and may be sensitive for a while, but this mostly decreases within 1 to 2 weeks. If tartar is left in place, gum disease can progress, the gums recede further and the sensitivity can grow.

Is root canal treatment ever needed for sensitive teeth?

Rarely. Root canal treatment for sensitive teeth is the last method considered when conservative treatments such as topical applications and fillings do not help and daily life is difficult. A tooth that has had root canal treatment tends to become weaker and is often covered with a crown, so decide after hearing the pros and cons fully.

Can children have sensitive teeth too?

Sensitive teeth are most common in the 30s and 40s, but children can also have them because of cavities or tooth damage. If a child avoids cold food or chews only on one side, check for cavities first.

References

Korean version →