Why Are My Teeth Sensitive to Hot or Cold?

Ouch! Tooth sensitivity is the simple term used to refer to root sensitivity or dentin hypersensitivity. Having sensitive teeth means cold, hot, sweet and highly acidic drinks and foods, or even breathing cold air will make you feel pain in your teeth.

This problem is common and is fortunately treatable.

Why does tooth sensitivity occur?

Tooth sensitivity develops when our gums recede, or when the enamel, the outer, protective layer of our teeth becomes thinner. This exposes dentin, which is the underlying surface of the tooth – weakening the protection that the gums and the enamel give to the root of the tooth.

Dentin, the material found in the inner tooth, is composed of tiny tubules which contain microscopic nerve endings.

A hard outer coating of enamel covers the dentine in the crown section of the tooth.

The dentine in the root of the tooth is protected by a layer of thin, bony material called the cementum.

Nerve irritation –or dentin hypersensitivity– is the result of dentin losing this protective coating of cementum or enamel.

The stimulated hypersensitive nerve endings become inflamed, painful and sensitive when exposed to cold, hot, sticky, or acidic foods and drinks, and sometimes even cold air.

Causes of tooth sensitivity

• Toothbrush abrasion –brushing teeth too hard, especially in a side-to-side motion. This leads to the wearing away of the enamel, particularly in the sections where teeth and gums meet. The newly exposed dentine becomes sensitive.

• Dental erosion –this refers to degradation of the tooth enamel due to acid attacks from acidic drinks and food. The worn enamel leads to dentine exposure, resulting in tooth sensitivity.

• Natural gum recession –this is when our gums recede or shrink back naturally, leaving the roots of the teeth exposed. The roots are therefore left with no protection, resulting in tooth sensitivity.

• Gum disease –Accumulation of tartar or plaque can result in the gum receding downward. This may even damage the bony material that supports the tooth.

Pockets may also develop in the gums surrounding the tooth, rendering such sections hard to clean properly and worsening the problem.

Occasionally, heat sensitivity may indicate that the tooth is infected by bacteria from the inside. These bacteria may enter through a cavity, a crack, or a leaking dental crown or filling.

Bacteria emit gas as part of their natural processes. Exposing such a tooth to heat makes the gas which is trapped inside the hollow tooth interior to heat up and expand. The expansion of this heated gas applies pressure to the hypersensitive nerve tissue, causing pain.

• Tooth grinding –This habit involves grinding and clenching teeth together. This leads to the wearing down of the tooth enamel which causes the sensitive nerves in the dentin to be inflamed, leading to tooth sensitivity.

The solution to this problem is to wear a dental night guard. You can wear a daytime and/or nighttime guard.

• A filling or cracked tooth –a cracked tooth is one which is broken. A crack may begin from the biting area of the tooth and continue downwards to the root. Severe temperatures, particularly cold, may cause immense discomfort.

• Tooth bleaching –There are people who briefly experience tooth sensitivity during or after the bleaching procedure.

How can I make my teeth less sensitive to hot and cold foods?

Tooth sensitivity can be reduced in several ways.

•  Brushing thoroughly with low-abrasion toothpaste (ex: Sensodyne tooth paste)
•  Wear a dental night guard to protect the teeth from grinding and clenching
•  Flossing daily is another way since this will eliminate plaque between gums and teeth
•  Reducing intake of highly acidic food and drinks will also prevent this problem.