Tooth sensitivity to cold is a common problem that can be caused by a variety of factors. Some possible causes of tooth sensitivity to cold include:

1. Tooth decay: Tooth decay, also known as cavities, can expose the dentin (the layer of tissue under the enamel) and cause sensitivity to cold and other stimuli.
2. Gum disease: Gum disease, or periodontal disease, can cause the gums to recede and expose the roots of the teeth. Exposed roots are more sensitive to temperature changes and may cause discomfort when eating or drinking cold foods and beverages.
3. Fractured teeth: If you have a cracked or broken tooth, the inner layers of the tooth may be exposed, causing sensitivity to cold.
4. Worn tooth enamel: Enamel, the outer layer of the tooth, protects the dentin from being exposed to stimuli. If the enamel is worn or damaged, it can cause sensitivity to cold.
5. Teeth grinding: Teeth grinding, also known as bruxism, can wear down the enamel and cause sensitivity to cold and other stimuli.

If you are experiencing tooth sensitivity to cold, it is important to see a dental professional for a proper diagnosis and treatment. Treatment may include filling a cavity, treating gum disease, repairing a fractured tooth, or using a desensitizing toothpaste. In some cases, your dentist may recommend a mouthguard to protect your teeth from grinding.