My teeth are sensitive to cold water and air, but the dentist says it's not a cavity. Why?

When the enamel at the neck of the tooth (cervical area) wears away or the gums recede, dentin is exposed, and cold stimuli reach the nerve through tiny tubules inside it, causing sensitivity. Causes vary, including cavities, abrasion, gum recession and teeth grinding, so they need to be told apart. In some cases sensitivity eases once the cause is managed.

Why does the resin filling at my tooth neck keep falling out?

The tooth neck takes repeated bending stress from chewing and grinding, so fillings there come loose easily. Hard side-to-side brushing and clenching are cited as causes, and unless these habits are managed, a redone filling may keep falling out.

Should I get GI or resin?

Glass ionomer (GI) is a material covered by National Health Insurance that can be placed without drilling the tooth. It releases fluoride and is easy to refill. Resin is tooth-colored and looks better, but it may come loose at the tooth neck, where biting force concentrates. The choice depends on the location, cosmetic needs and history of fillings falling out.

I have no symptoms, but the dentist recommends a filling because the abrasion is getting worse. Do I need it?

If the abrasion is mild and causes no symptoms, some dentists correct brushing to a gentler technique, use desensitizing toothpaste and fluoride, and monitor it. Not drilling healthy tooth structure is considered first, and a filling is considered if sensitivity is severe or the wear deepens, so discuss it with your dentist based on the diagnostic evidence.

← Cavities guide

Cervical Abrasion and Sensitive Teeth: Telling It Apart from Cavities, GI vs. Resin, and When to Monitor Without Drilling

Published August 24, 2026 Updated August 24, 2026 Based on official HIRA and Ministry of Health and Welfare data and public sources

In the analysis of patient comments about Cavities, Cervical abrasion and sensitivity formed a question cluster of about 1,100 comments. Sensitivity to cold water is often caused by worn tooth necks or receding gums, not cavities. Covers why fillings there fall out, GI vs. resin, monitoring without drilling, and what desensitizing toothpaste can do. SOURCE Analysis of patient comments on YouTube dental content (DentStat) · public sources listed under References · Data as of June 28, 2026

Key facts

Causes of sensitivity	Besides cavities, cervical abrasion, gum recession and teeth grinding need to be ruled out ^[1]
Fillings falling out	Fillings at the tooth neck often come loose due to bending stress from chewing and grinding ^[1]
GI properties	Can be placed without drilling, releases fluoride, covered by National Health Insurance ^[2]
Desensitizing toothpaste	An aid for relieving symptoms (quasi-drug); does not replace treating the cause ^[3]
Comments analyzed	1,100 comments on cervical abrasion and sensitive teeth ^[4]

My teeth hurt with cold water or cold air. Is it a cavity?

It may be a cavity, but sensitivity is often caused by cervical abrasion or gum recession exposing the root [1]. When the enamel at the neck of the tooth (cervical area) wears away or the gums recede, dentin is exposed, and stimuli such as cold water, cold air or breathing in reach the nerve through tiny tubules inside it, causing sensitivity [1]. Causes vary, including cavities, abrasion, gum recession, and teeth grinding or bite problems, so they need to be told apart, and in some cases sensitivity eases once the cause is managed [1].

DentStat analyzed 1,100 patient comments about cervical abrasion and sensitive teeth on YouTube dental content. Many showed frustration with fillings repeatedly falling out and confusion along the lines of “it’s not a cavity, but it’s still sensitive” [4].

Why does the tooth neck wear into a notch, and why does resin there keep falling out?

The tooth neck takes repeated bending stress from chewing and grinding, so enamel chips off in a wedge shape and fillings come loose easily [1]. Brushing hard from side to side and habits such as grinding and clenching are cited as factors that advance cervical abrasion [1]. Because force concentrates here, a filling may keep falling out unless the habits behind it are managed [1]. Rather than simply redoing the filling, addressing the cause means also correcting brushing technique and managing grinding [1].

How do GI and resin differ for restoring the tooth neck?

Glass ionomer (GI) is a covered material that can be placed without drilling the tooth, while resin looks better but may come loose and is usually non-covered (not paid by Korea’s National Health Insurance) [2]. GI releases fluoride and keeps tooth removal to a minimum, so it is used in areas like the tooth neck, and refilling it is less of a burden if it falls out [2]. Resin is tooth-colored and looks natural, but at the tooth neck, where biting force concentrates, it may come loose more often [1].

Material	Features	Health insurance
Glass ionomer (GI)	Placed without drilling, releases fluoride, relatively less resistant to wear	Covered [2]
Composite resin	Tooth-colored and cosmetic, may come loose at the tooth neck	Non-covered (adults) [2]

Neither is always better; the choice depends on the location, cosmetic needs and history of fillings falling out [1].

Should I get a filling in advance even without symptoms?

If the abrasion is mild and causes no symptoms, some dentists monitor it instead of filling it right away [1]. When wear is not severe and there is no sensitivity, one approach is to correct brushing to a gentler technique, use desensitizing toothpaste and fluoride, and watch how it develops, with not drilling healthy tooth structure considered first [1]. Some patients actually reported more sensitivity after a resin filling, so the decision should be based on symptoms and how far the wear has progressed [4]. A filling is considered if sensitivity is severe or the wear deepens, so whether to fill now or monitor is something to discuss with your dentist based on the diagnostic evidence [1].

Does desensitizing toothpaste work?

It is an aid for reducing symptoms and does not replace treating the cause [3]. Toothpaste with desensitizing ingredients is a quasi-drug designed to relieve sensitivity by blocking the tiny tubules in dentin or dulling the nerve response, and it needs to be used consistently to have an effect [3]. However, if causes such as abrasion, gum recession or grinding remain, toothpaste alone has limits, so identifying and managing the cause is also needed [1].

Common myths and facts

Common myth	What the evidence shows
”All sensitivity is caused by cavities”	It is often caused by cervical abrasion, gum recession or teeth grinding [1]
“Brushing harder and longer cleans better”	Hard side-to-side brushing can cause cervical abrasion [1]
“Resin is always better than GI at the tooth neck”	GI has advantages (no drilling, insurance coverage, easy refilling) and is chosen depending on the location [2]
“You should fill it early even without symptoms”	Mild, symptom-free cases are sometimes monitored without drilling [1]
“Desensitizing toothpaste alone will fix it”	Without managing the cause, it only helps relieve symptoms [1][3]

For cavity and sensitivity stages and health insurance in general, see the cavity guide. For dental clinics by area, see find a dentist.

Frequently asked questions

My teeth are sensitive to cold water and air, but the dentist says it's not a cavity. Why?: When the enamel at the neck of the tooth (cervical area) wears away or the gums recede, dentin is exposed, and cold stimuli reach the nerve through tiny tubules inside it, causing sensitivity. Causes vary, including cavities, abrasion, gum recession and teeth grinding, so they need to be told apart. In some cases sensitivity eases once the cause is managed.
Why does the resin filling at my tooth neck keep falling out?: The tooth neck takes repeated bending stress from chewing and grinding, so fillings there come loose easily. Hard side-to-side brushing and clenching are cited as causes, and unless these habits are managed, a redone filling may keep falling out.
Should I get GI or resin?: Glass ionomer (GI) is a material covered by National Health Insurance that can be placed without drilling the tooth. It releases fluoride and is easy to refill. Resin is tooth-colored and looks better, but it may come loose at the tooth neck, where biting force concentrates. The choice depends on the location, cosmetic needs and history of fillings falling out.
I have no symptoms, but the dentist recommends a filling because the abrasion is getting worse. Do I need it?: If the abrasion is mild and causes no symptoms, some dentists correct brushing to a gentler technique, use desensitizing toothpaste and fluoride, and monitor it. Not drilling healthy tooth structure is considered first, and a filling is considered if sensitivity is severe or the wear deepens, so discuss it with your dentist based on the diagnostic evidence.
Will desensitizing toothpaste alone fix it?: Desensitizing toothpaste is a quasi-drug designed to relieve sensitivity by blocking the tiny tubules in dentin or dulling the nerve response, and it needs to be used consistently to have an effect. However, if causes such as abrasion, gum recession or grinding remain, toothpaste alone has limits, and the cause also needs to be managed.

Find a dental clinic

Compare dental clinics by area and treatment in the area shortlists, or see nationwide figures in dental clinic statistics for South Korea.

References

National Health Information Portal: Dental Caries and Tooth Sensitivity · Korea Disease Control and Prevention Agency (KDCA)
National Health Insurance Coverage Criteria for Glass Ionomer (GI) Fillings · Ministry of Health and Welfare · National Health Insurance Service (NHIS)
Standards for Quasi-Drugs Including Desensitizing Toothpaste · Ministry of Food and Drug Safety (MFDS)
Analysis of Patient Comments on YouTube Dental Content: 1,100 Cavity Comments on Cervical Abrasion and Sensitivity (collected 2026-06-28) · DentStat (Osamil Inc.)

This content is general information based on public sources and does not replace diagnosis, prescription or treatment for any individual. If you have symptoms, consult a dentist.