A tooth that is sensitive to cold usually means cold is reaching the inner layer of the tooth, called dentin, through gum recession, worn enamel, a cavity, a crack or a worn filling. A short twinge that fades within seconds is generally less concerning than pain that lingers after the cold is gone, which should be checked by a dentist.
In a study of patients at general dental practices published in the Journal of the American Dental Association, about one in eight participants had dentin hypersensitivity. It was more common in people with gum recession. The good news is that an exam can usually identify the cause.
Why is my tooth sensitive to cold?
Healthy teeth are protected by enamel on the crown and by the gums over the roots. Underneath is dentin, which contains tiny channels called tubules. According to the American Dental Association, these tubules allow heat and cold, as well as acidic or sticky foods, to reach the nerves and cells inside the tooth. When the protective layer is lost, cold water, ice cream or even a breath of cold air can cause a sharp twinge.
The ADA lists these common causes of sensitive teeth:
- Tooth decay (cavities)
- Fractured or cracked teeth
- Worn fillings
- Gum disease
- Worn tooth enamel
- Exposed tooth roots, since dentin can be exposed when gums recede
If your gums have pulled back, our article on exposed tooth roots and gum recession explains why roots become uncovered and what can help.
Why is one tooth suddenly sensitive to cold?
When sensitivity appears in a single tooth rather than across the whole mouth, it often points to something local to that tooth, such as a new cavity, a crack, a filling that has worn or broken down, or a small area of gum recession. These problems can look similar from the outside, which is why an exam is the most reliable way to find the cause.
Tooth sensitive to cold and hot: what is the difference?
How long the pain lasts can be more telling than what triggers it. Guidance from the American Association of Endodontists describes how dentists interpret a tooth's response to cold:
- A healthy tooth may have a mild response to cold that lasts no more than one to two seconds after the cold is removed.
- When the nerve is irritated but expected to recover, discomfort from cold or sweets goes away within a couple of seconds. The pain does not start on its own.
- When the nerve is more seriously inflamed, the AAE describes sharp pain with hot or cold, lingering pain that often lasts 30 seconds or longer and pain that starts on its own without a trigger.
The AAE also notes that over the counter pain relievers are typically ineffective for that more serious kind of nerve inflammation. Only an exam with appropriate testing can tell which situation applies to your tooth, so treat these descriptions as a reason to book a visit rather than a way to diagnose yourself.
How can I stop my teeth from being sensitive to cold?
The right approach depends on the cause. Treatments the ADA describes include:
- Desensitizing toothpaste. It contains compounds that help block sensation from traveling from the tooth surface to the nerve.
- Fluoride gel applied in the office. This strengthens enamel and reduces the transmission of sensations.
- A filling, bonding, inlay or crown. These can correct a flaw or decay that is causing sensitivity. For small areas of decay, tooth colored fillings are a common way to repair the tooth.
- A gum graft. If gum tissue has been lost from the root, a graft can protect the root and reduce sensitivity.
- Root canal treatment. The ADA describes this as an option when sensitivity is severe and persistent and cannot be treated by other means.
At home, the ADA recommends brushing twice a day with a soft bristled brush and an ADA accepted fluoride toothpaste, holding the brush at a 45 degree angle to the gums and moving it gently in short strokes. The ADA notes that proper oral hygiene is the key to preventing sensitive tooth pain.
Can teeth whitening make teeth sensitive to cold?
It can. The ADA explains that some people who use whiteners experience sensitivity when the peroxide reaches the dentin and irritates the nerve of the tooth. In most cases this sensitivity is temporary. Following the product directions and talking with your dentist before whitening can help, especially if your teeth are already sensitive.
When to see a dentist
Make an appointment if your sensitivity is new, keeps returning, is limited to one tooth or is getting worse. Seek care sooner if:
- The pain lingers well after the cold is gone
- The tooth aches on its own without a trigger
- You have a severe toothache, or a toothache that lasts longer than a day or two, which MedlinePlus advises should be checked
- The tooth also hurts to bite on, or you notice swelling
If you are not sure how urgent your symptoms are, our Where does it hurt? symptom guide can help you decide on next steps.
What to expect at our Palo Alto office
At our office in Midtown Palo Alto, Dr. Sharma will ask when the sensitivity started and what triggers it, then examine the tooth, the gums and any existing fillings or crowns. Depending on what he finds, he may recommend imaging or simple tests to check how the tooth responds. He will explain what he sees and the options before any treatment is recommended. When a tooth is painful, same day emergency visits are available Monday through Thursday and on Friday mornings.
Common questions
Is it normal for a tooth to be sensitive to cold?
A brief reaction to something very cold can be normal. Sensitivity that is sharp, keeps happening or lingers is not something you need to live with. A dentist can find the cause and suggest treatment.
Does a tooth sensitive to cold mean I need a root canal?
Not necessarily. Sensitivity can come from exposed dentin or from a problem that a filling or bonding can fix. The ADA describes root canal treatment as an option for severe, persistent sensitivity that cannot be treated by other means. Only an exam can tell which applies.
Will desensitizing toothpaste fix a sensitive tooth?
It can help when sensitivity comes from exposed dentin, because it helps block sensation from reaching the nerve. It will not repair a cavity, a crack or a broken filling, so sensitivity that continues or is limited to one tooth should be examined.
If a tooth has been bothering you, please request an appointment or call us at (650) 321-9693.
Sources
American Dental Association, MouthHealthy: Sensitive Teeth
American Dental Association, MouthHealthy: Brushing Your Teeth
American Dental Association, MouthHealthy: Teeth Whitening
American Association of Endodontists: Endodontic Diagnosis (Colleagues for Excellence)
MedlinePlus Medical Encyclopedia: Toothaches
This article provides general education and does not replace an individual dental examination or diagnosis.
