Tooth Sensitivity Explained: Why It Happens and When to See a Dentist
If you’ve ever felt a sudden, sharp twinge when sipping a cold drink or brushing your teeth, you’re not alone. Tooth sensitivity — or dentine hypersensitivity, as we call it — affects millions of people. It’s one of those things that can seem minor at first, but when it starts happening often, it’s hard to ignore.
So, when does sensitivity become something you should actually see a dentist about? Let’s break it down.
Why Teeth Get Sensitive
Every tooth has a hard outer shell of enamel. Underneath that is a softer layer called dentine — and inside the dentine are tiny tubules that connect straight to the tooth’s nerve. When enamel wears thin or gums recede, those little tubes become exposed. Suddenly, cold air, hot tea, or even your toothbrush can trigger a burst of discomfort.
There are lots of reasons this can happen, including:
Brushing too hard: Scrubbing aggressively (especially with a firm brush) can wear down enamel and push gums back.
Acidic foods and drinks: Citrus, fizzy drinks, and even wine can gradually dissolve enamel.
Gum recession: Often caused by gum disease or over-brushing, it exposes the sensitive root surface.
Tooth wear or cracks: Everyday grinding or minor fractures can open up dentine.
Dental treatments: Whitening or new fillings can temporarily make teeth react to hot and cold.
Most of the time, these issues develop slowly — but they can sneak up on you if you’re not paying attention.
How to Tell If It’s “Normal” Sensitivity or Something More
Occasional twinges after an ice-cold drink aren’t usually cause for concern. But there are a few signs that your sensitivity might point to something more serious:
The pain lingers after the trigger (e.g. the cold drink is long gone, but your tooth still aches).
The sensitivity is getting worse instead of better.
It’s affecting just one tooth rather than a few.
You notice other changes — like swollen gums, dark spots, or a strange taste.
If any of those sound familiar, it’s worth seeing your dentist sooner rather than later. Persistent sensitivity can sometimes signal decay, gum disease, or a damaged filling — and catching it early makes treatment simpler and less costly.
What You Can Do at Home
If your sensitivity is mild, there are a few small changes that can make a big difference:
Switch your toothpaste.
Desensitising toothpastes (like Sensodyne Repair & Protect) help block those tiny tubules in the dentine, calming the nerve response over time.
Use an electric brush — gently.
Let the brush do the work rather than scrubbing. A pressure sensor is ideal because it tells you when you’re pressing too hard.
Rinse with fluoride.
A daily fluoride mouthwash strengthens enamel and makes teeth more resistant to acids.
Watch your diet.
If you love citrus, sparkling water, or wine, try having them with meals and rinse your mouth with water afterwards to neutralise acids.
If you’re not sure what’s causing your sensitivity, it’s better to get it checked before you start experimenting with lots of products. A short appointment can rule out deeper problems.
When to See a Dentist
Here’s the rule of thumb:
If the sensitivity is sharp, one-sided, or lasting longer than a few seconds — book an appointment.
Your dentist can check for enamel loss, gum recession, or hidden decay. They might recommend:
A fluoride varnish or gel to strengthen enamel.
Bonding or a small filling to cover exposed dentine.
A gum graft if recession is the main issue.
In rare cases, a root canal if the nerve is permanently irritated.
Most people, though, don’t need anything drastic — just the right care plan and a few habit tweaks.
The Bottom Line
Tooth sensitivity isn’t something you have to live with, and it’s not always a sign of serious trouble. But if it’s happening often, or it’s making you avoid certain foods or drinks, that’s your cue to get checked out.
