Dental Health
Sensitive Teeth: Why Cold and Hot Hurt, and What Actually Fixes It
A jolt from cold water, or a wince at the first sip of hot tea — around one in three patients we see mentions this. Most assume it is simply age. In truth there is always a specific cause, and most of those causes are treatable.
What is happening inside the tooth
The outer layer, enamel, is the hardest tissue in the body and contains no nerves. Beneath it sits dentine, and this is where the story lies: dentine is threaded with millions of microscopic tubules running directly to the nerve inside the tooth.
While enamel and gum cover the dentine, you feel nothing. Once dentine is exposed, hot and cold move the fluid inside those tubules, the nerve registers the movement, and you feel that sharp jolt.
Six common causes
1. Brushing too hard
The most common cause, and the easiest to stop. A hard brush used with force in a scrubbing motion wears away enamel at the neck of the tooth and pushes the gum back. Clean teeth come from technique, not pressure.
2. Gum recession
Gum disease or years of wear expose the root, which has no enamel covering at all and becomes sensitive quickly. This is why gum problems and sensitivity so often travel together.
3. Abrasive tooth powders and charcoal
Common in this region and genuinely damaging. These are gritty, and years of scrubbing thin the enamel. Read more: gul, manjan, datun and charcoal.
4. Acidic foods and drinks
Lemon, tamarind, pickle, cold drinks and frequent sweet tea dissolve enamel gradually. Brushing immediately after something acidic makes it worse, because enamel is softened at that moment.
5. Grinding (bruxism)
Night-time grinding wears chewing surfaces and creates stress cracks at the neck of the tooth. Many people have no idea they do it until a family member mentions it or they wake with a tight jaw.
6. A cavity or cracked tooth
This is the category not to ignore.
What helps at home
- Switch to a soft brush and use small, gentle circles rather than scrubbing
- Use a desensitising toothpaste consistently — it takes two to four weeks to work
- Smear a little of that toothpaste onto the sensitive area with a fingertip and leave it without rinsing — more effective than brushing alone
- Stop tooth powders, charcoal, salt and ash completely
- Do not brush straight after acidic food — rinse with water and wait half an hour
- Avoid taking very hot and very cold together
What we can do in the clinic
Treatment depends entirely on the cause, which is why an examination matters:
- Fluoride varnish — strengthens exposed surfaces and reduces sensitivity
- Desensitising agents — seal the open tubules
- A filling — where there is decay or a worn notch
- Gum treatment — where recession is the cause
- A night guard — for grinders
- Root canal treatment — only where the nerve is already involved
When not to wait
These signs mean this has gone beyond simple sensitivity: pain lingering minutes after the trigger is removed; pain starting spontaneously; pain worse lying down at night; sharp pain on biting; or swelling near the gum. Treated early, a simple filling is usually enough. Left alone, the same tooth often ends up needing a root canal.
Living with sensitive teeth? Guessing at the cause wastes months. Book an assessment at Janata Dental Clinic, Muzaffarpur — consultation ₹200, call 95726 63116.
Frequently Asked Questions
Why do my teeth hurt with cold and hot?
Beneath the enamel lies dentine, which contains millions of microscopic tubules running to the tooth's nerve. When enamel wears away or the gum recedes and exposes the root, those tubules open. Temperature changes then move fluid inside them and the nerve registers it as a sharp jolt.
Does sensitivity go away on its own?
Sensitivity following a cleaning or another temporary cause usually settles within a few weeks. But if the cause is a cavity, a cracked tooth or gum recession, it will not resolve by itself and needs treatment.
When is sensitivity a warning sign?
If pain lingers for minutes after the cold or hot is removed, starts on its own, wakes you at night, or is sharp when you bite down, it is no longer simple sensitivity. That pattern suggests the nerve is involved and needs prompt assessment.