On this page · 6 sections
01Why it matters
A tooth has three main layers. Enamel is the hard outer shell. Dentin is the middle layer and makes up most of the tooth. The pulp is the soft center, where the nerve and blood vessels live.
Dentin is softer than enamel, so decay moves through it faster. It is also full of tiny tubes called tubules. These tubes carry feelings like cold or heat toward the nerve. That is why exposed dentin can cause a sharp, quick twinge.
Text version of this infographic
Cross-section of a tooth. Enamel is the hard outer shell. Dentin is the softer, yellowish layer under it, with tiny tubes that lead toward the pulp. When dentin is exposed, teeth can feel sensitive to hot, cold or sweet things.
02Signs and causes
Dentin is normally covered and protected. Problems start when it is exposed or reached by decay. Common signs include:
- A quick, sharp pain with cold drinks, hot foods, or sweets.
- Sensitivity when you brush or breathe in cold air.
- A yellow or dark spot where the enamel has worn thin.
- A hole or rough spot you can feel with your tongue.
Causes include a cavity, worn tooth enamel, and gums that pull back from the teeth. Brushing too hard and sipping acidic drinks can wear enamel away. So can grinding your teeth, which is called bruxism.
03What happens
The dentist looks at the tooth and may take X-rays to see how deep any damage goes. Treatment depends on what is found:
- Sensitivity only. A special toothpaste or a coating painted on the tooth may calm it.
- Small to medium decay. The decay is removed and the tooth is repaired with a filling.
- Large damage. A crown may be needed to cover and protect the tooth.
- Decay that reaches the pulp. A root canal may be needed to treat the nerve.
A tooth can make a little new dentin on its own to shield the nerve. It cannot rebuild a hole, though. After a cavity forms, it needs a dentist's care.
04Cost factors
What you pay depends on what the exam finds, and the office can explain it before treatment:
- The kind of care needed, from a toothpaste change to a filling or crown.
- How many teeth are involved and how deep the damage goes.
- The filling or crown material chosen.
- Your dental insurance plan and what it covers. Call the office to check your plan.
- Whether you choose to use CareCredit, a healthcare financing option the office accepts.
05How to protect your teeth
Brush twice a day with a soft brush and fluoride toothpaste. Use gentle strokes, not hard scrubbing. Clean between your teeth once a day.
Drink sour or acidic drinks like soda or juice with meals, and rinse with water after. If you grind your teeth, tell the dentist. Keep up with regular checkups so small problems are caught early. Call the office if a tooth starts to feel sensitive.
Worried about sensitive teeth? See our dental fillings page.
06Questions people ask
Can dentin grow back?
Not the way skin heals. A tooth can make a small amount of new dentin inside to protect the nerve. But it cannot fill in a hole or replace lost dentin. A dentist repairs that with a filling or a crown.
Why does exposed dentin make my teeth sensitive?
Dentin is full of tiny tubes that lead toward the nerve. When enamel or gums no longer cover it, cold, heat, and sweets can reach those tubes. That sets off a quick, sharp feeling in the tooth.
Is dentin the same as enamel?
No. Enamel is the hard outer layer that you see. Dentin is the softer, yellowish layer under it. Dentin makes up most of the tooth and surrounds the pulp, where the nerve lives.
Can toothpaste help sensitive teeth?
Often, yes. Toothpaste made for sensitive teeth can block the tiny tubes in dentin when used daily. It may take a few weeks to feel a change. See the dentist if the pain lasts, since it can be a sign of decay.
Dr. Sadek is the family dentist at Americana Family Dental on Americana Blvd in Orlando. He reviews the health information on this site. Review date: [date pending review]