My upper left molar tooth is sensitive to cold and air. The tooth has a large filling. Two days ago, I went to the dentist, and she used a tool to blow air on the tooth in different areas. She asked if the air made the tooth hurt or sensitive (it did). Afterward, my dentist put a desensitizing agent on the tooth and said the sensitivity should decrease. Is that it? Did I get an accurate diagnosis in five minutes, or was my dentist brushing me off? What has been causing the sensitivity? Dylan from NH
Sometimes sensitivity in a tooth is easy to diagnose. At other times, it is more complicated. But your dentist performed a standard test to determine the source of discomfort. Dr. Cha would need to examine your tooth and filling for an accurate diagnosis.
Air Test for Tooth Sensitivity
A dentist might blow air on a tooth to determine if any portion of it is unprotected and sensitive. A desensitizing bonding agent will coat and protect the tooth.
What Causes a Tooth to Be Sensitive to Cold?
The cause of cold sensitivity in a tooth depends on the pain you are feeling and the tooth’s condition. In many cases, a tooth might be sensitive to cold and heat.
Type of pain
- Pain that goes away quickly – The tooth pulp (the living tissue inside the tooth) or nerves are irritated, but they could heal.
- Lingering pain – When an air test provokes lingering pain, tooth pulp or nerve irritation will not heal by itself. Your dentist can perform a root canal treatment to remove the pulp and nerves.
- Established filling – Any space between filling edges and your tooth allows bacteria to leak in. Tooth decay beneath the filling will cause pain and sensitivity to cold.
- New filling – Sensitivity immediately after getting a new silver or composite filling is normal. But if sensitivity begins later, it usually means that bacteria from the previously decayed tooth infected the pulp (the living tissue inside the tooth). You may need root canal treatment to resolve it.
- Wisdom tooth extraction – Although it rarely occurs, sometimes during wisdom tooth extraction, the adjacent tooth’s root is exposed and becomes sensitive. Toothpaste for sensitive teeth often resolves the issue. According to the American Dental Association, it takes several applications before desensitizing toothpaste relieves your symptoms. If not, your dentist can apply a desensitizing agent to the tooth.
- Tooth decay – Decay or infection can irritate tooth pulp and make your teeth sensitive to cold or heat.
- Fracture – A fracture can irritate tooth nerves and increase sensitivity to cold. If you leave the tooth untreated, pulp damage can become irreversible and require root canal treatment and a dental crown.
- Gum recession – If your gums are receding—or pulling away from your teeth—exposed tooth roots can be sensitive to cold or heat. Desensitizing toothpaste may help, or your dentist may recommend a gum grafting procedure to cover the exposed roots and reduce sensitivity.
- Worn tooth enamel – When tooth enamel wears down, dentin (the layer beneath the enamel) is exposed. Without protection from tooth enamel, heat and cold can enter the dentin and stimulate tooth nerves. Dentin contains small tubes that lead to tooth nerves.