Tooth sensitivity is a short, sharp pain when something cold, hot, sweet or sour reaches a part of the tooth that is exposed. It is common, and it is worth understanding because some causes settle with a change of habit while others need treatment.
Common causes
- Worn enamel, often from brushing hard with a stiff brush, or from acidic drinks.
- Receding gums, exposing the root surface, which is far more sensitive than enamel.
- A cracked or chipped tooth.
- Decay, particularly when it reaches the inner layers.
- Grinding or clenching, which wears the biting surfaces down.
- After treatment, such as a new filling or whitening — this type usually settles.
Which sensitivity needs a dentist
See a dentist if:
- the pain lingers for more than a few seconds after the trigger is removed;
- it wakes you at night, or throbs on its own;
- one specific tooth hurts when you bite;
- the gum near the tooth is swollen.
Lingering or spontaneous pain suggests the nerve inside the tooth is involved, which may need root canal treatment rather than a desensitising toothpaste.
What helps everyday sensitivity
- Switch to a soft brush and brush gently along the gum line rather than scrubbing across it.
- Use a desensitising toothpaste consistently — it works over weeks, not overnight.
- Cut back on acidic drinks, and rinse with water afterwards rather than brushing immediately.
- Treat grinding. A night guard protects the teeth if you clench in your sleep.
- Have receding gums assessed rather than assuming they are just age.
What your dentist can do
Treatment depends on the cause: a filling for decay or a worn notch at the gum line, fluoride application to strengthen enamel, gum treatment where recession is caused by disease, a night guard for grinding, or root canal treatment where the nerve is involved.
Common questions
Is sensitivity always serious? No, but it is a signal. The distinction that matters is brief pain that stops versus pain that lingers.
Does whitening cause permanent sensitivity? Mild sensitivity after whitening is usually short-lived and managed with a desensitising gel.
Read more about tooth-coloured fillings and fluoride treatment, or book a consultation.