Sensitive teeth: causes and what helps
Sensitivity happens when the layer beneath the enamel is exposed. Most of the time it is manageable — but a short sharp twinge and a lingering ache mean quite different things.
The distinction that matters
Sensitivity that stops within a second or two of the cold being removed is usually exposed dentine. It is uncomfortable rather than serious, and often improves with a change of toothpaste and technique.
Pain that lingers for many seconds or minutes after the trigger has gone suggests the nerve inside the tooth is inflamed. That is a different problem and needs examining, because it does not settle on its own.
Why dentine becomes exposed
Common causes, roughly in order of how often we see them:
- Gum recession, exposing the root surface which has no enamel
- Brushing too hard, or with a hard-bristled brush
- Acid erosion from fizzy drinks, citrus, or acid reflux
- Grinding and clenching, which wears the biting surfaces
- Recently placed fillings, which usually settle within a few weeks
- After a professional clean, which typically settles in days
- Cracks in the tooth
Whitening and sensitivity
Temporary sensitivity during whitening is normal and settles after treatment finishes. Sensitivity that persists well beyond it is not, and should be checked. Supervised whitening at appropriate concentrations does not damage enamel; repeated unsupervised use of over-the-counter or salon products is where problems arise.
When to be seen, and how soon
This is general guidance, not a diagnosis. If you are unsure, message us and describe what is happening.
- Severe pain with facial swelling or fever
- Pain that lingers well after hot or cold is removed
- Sensitivity in one specific tooth that is getting worse
- Sensitivity with pain on biting, which can indicate a crack
- A tooth that has become sensitive after a knock
- General sensitivity across several teeth that has been stable for a long time
- Sensitivity for a few days after a filling or a clean
- Mild sensitivity to very cold drinks only
What you can do meanwhile
Worth trying for a few weeks before assuming treatment is needed:
- Use a desensitising toothpaste and give it at least two to four weeks to work
- Smear it on the sensitive area with a finger before bed and do not rinse it off
- Switch to a soft brush and stop scrubbing — pressure causes more wear than bristle stiffness
- Wait an hour after acidic food or drink before brushing
- Use a straw for fizzy or citrus drinks
- If you wake with jaw ache, mention grinding at your appointment
How we treat it
Which of these applies depends on the cause, which an examination confirms:
- Teeth cleaning — when deposits and gum inflammation are contributing
- Gum disease treatment — when recession has exposed the root surface
- Root canal treatment — when the pain lingers and the nerve is involved
- Crowns — when a cracked or worn tooth needs covering
Common questions
How long should desensitising toothpaste take to work?
Usually two to four weeks of consistent use. It works by blocking the tiny tubules in exposed dentine, which is gradual. Stopping after a few days is the most common reason people conclude it has not helped.
Is sensitivity a sign of a cavity?
It can be, but often it is not. Generalised sensitivity across several teeth is more typically exposed dentine. Sensitivity in one specific tooth, especially if it lingers, is more likely to be decay or a crack.
Does whitening permanently damage enamel?
Professionally supervised whitening at appropriate concentrations does not. Sensitivity during treatment is common and temporary. Repeated unsupervised use of over-the-counter products is where problems occur.
Can sensitive teeth be treated permanently?
It depends on the cause. Recession-related sensitivity can often be managed well but may recur. Sensitivity from a crack or decay is resolved by treating the tooth itself.
This page is general information and does not replace an examination. If you are in significant pain or have facial swelling, contact us or seek urgent care rather than waiting.