Pain in the teeth when consuming hot or cold foods is commonly due to tooth sensitivity. This usually happens when the protective layer of the tooth becomes thin or when the gums recede, exposing the inner part of the tooth. It may also be caused by tooth decay, worn fillings, or enamel erosion from acidic foods and drinks. To reduce this discomfort, use a toothpaste designed for sensitive teeth, as it helps block pain signals from the tooth to the nerve. Brush gently with a soft-bristle brush to avoid further damage to the enamel and gums. Avoid very cold or very hot foods and drinks when possible, as sudden temperature changes can trigger pain. It is also helpful to reduce intake of acidic items such as soft drinks and citrus fruits, as they may worsen enamel wear. Maintaining good oral hygiene by brushing twice daily and flossing can prevent further problems. If tooth pain persists or worsens, please visit a dentist, who may advise fluoride applications, cavity fillings, or treatment of gum problems to protect the exposed tooth surface.

It sounds like you are experiencing enamel erosion and dentin hypersensitivity. To strengthen your teeth and reduce sensitivity, I recommend using a toothpaste containing potassium nitrate (to calm the dental nerves) and sodium fluoride or calcium sodium phosphosilicate (to remineralize and strengthen enamel). Additionally, you can apply a weekly neutral sodium fluoride gel. Always use a soft-bristled toothbrush and avoid brushing immediately after eating acidic fruits; instead, rinse with water and wait 30 minutes to protect your enamel. Please visit a dentist for a professional checkup to rule out any underlying issues.