That jolt when cold water hits a tooth — ngilu — is one of the most common complaints in dentistry, and one of the most commonly ignored. Usually it is not an emergency. Sometimes it is the first sign of something that becomes one.
The difference is easy to work out once you know what to pay attention to.
What is actually happening?
Teeth are built in layers. Enamel on the outside is hard and has no nerve supply. Underneath is dentine, which is softer and — this is the important part — threaded with thousands of microscopic tubes running inward toward the nerve.
When dentine is covered, those tubes are sealed off and you feel nothing. When dentine is exposed, cold, heat, sweetness and acid can move down them and reach the nerve directly.
That is sensitivity. It is not weak teeth or thin nerves. It is a covering problem.
What exposes dentine in the first place?
| Cause | What is happening | Reversible? |
|---|---|---|
| Gum recession | The gum pulls back, exposing root surface, which has no enamel at all | The recession does not grow back |
| Brushing too hard | Abrasion wears enamel at the gumline and drives recession | Damage stays; further loss is preventable |
| Acid erosion | Fizzy drinks, citrus, reflux dissolve enamel over time | Lost enamel does not regrow |
| Grinding | Wears through enamel on the biting surfaces | Wear stays; the grinding is treatable |
| Decay | A hole through enamel into dentine | Treatable — this is a filling |
| A cracked tooth | Flexing lets fluid move in the tubes | Needs assessment |
| Recent treatment | Nerve irritated after a filling, or newly cleaned root surfaces | Usually settles |
Notice how many of those are cumulative and one-directional. Enamel does not come back, and neither does gum. That is the argument for dealing with the cause rather than only managing the symptom.
The test that tells you which kind you have
Time it. This one distinction separates “manage at home” from “get this looked at”.
Ordinary sensitivity: a sharp twinge on contact with cold, sweet or air, gone within a few seconds of removing the trigger. Often affects several teeth. No pain in between.
A problem in one tooth: the ache lingers — a minute or more after the cold has gone. Or pain starts spontaneously with no trigger at all. Or it is one specific tooth, every time, and getting worse.
Lingering pain suggests the nerve inside that tooth is inflamed rather than simply exposed. That is a different situation and it does not usually resolve on its own — see what tooth pain means for where it goes next.
What actually helps?
For genuine dentine sensitivity:
- A sensitivity toothpaste, used consistently. These work either by blocking the dentine tubes or by calming the nerve’s response. Both need weeks of daily use, not one application. Many people try it twice, feel no change, and give up a fortnight early.
- Rub a little into the sensitive spot with a fingertip and leave it rather than rinsing immediately. Contact time is doing the work.
- Switch to a soft brush and ease off the pressure. If your bristles splay within a month, you are brushing too hard.
- Wait 30–60 minutes after anything acidic before brushing. Enamel is temporarily softened after acid; brushing straight away removes more of it. This is the opposite of most people’s instinct.
- Cut back on the acid source if there is an obvious one — fizzy drinks sipped through the day are worse than the same volume drunk quickly, because the exposure lasts longer.
What does not help: brushing harder, brushing more often, or avoiding the sensitive tooth altogether. The last one lets plaque build exactly where the tooth is already vulnerable.
When should I stop managing it and get it seen?
- The pain lingers after the trigger goes
- It is one tooth, consistently
- It has appeared suddenly rather than creeping up over months
- It wakes you at night
- There is visible damage — a chip, a hole, a lost filling
- Sensitivity toothpaste used properly for four to six weeks has made no difference
- The gum around the sensitive tooth is swollen or bleeding
That last one matters because sensitivity and gum disease often travel together — recession exposes root, and the same inflammation is doing both.
What we do about it
At FTS Chin Dental in Likas, the first job is finding out which of the causes above applies, because the treatments are completely different:
- We check for decay, cracks and failing fillings — all three mimic sensitivity
- We look at how much gum recession there is and where
- We look for wear patterns that suggest grinding or acid erosion
- We test how the tooth responds to cold and to biting, and how long the response lasts
- An X-ray where the surface examination does not explain what you are describing
If it is genuine dentine sensitivity, treatment is about covering or calming exposed dentine and removing whatever is causing more of it. If it is decay, that is a filling — from RM100. If it is a crack or the nerve is involved, that is a different conversation and we will have it plainly.
If the pain lingers or wakes you rather than twinging and stopping, start with why toothache gets worse at night. If your gums bleed as well as being sensitive, why gums bleed covers the other half.