A wide range of factors has been considered as the cause of tooth sensitivity. Some have been discussed below as follows: –

Have u experienced an extreme cold or hot sensation while sipping a cold coffee or hot tea occasionally? Have you found brushing creating an abnormal sensation occasionally that makes you wince in pain?  If yes, then you may have sensitivity in your teeth.

 Tooth decay (cavities)

The tooth is usually comprised of an outer layer namely, Enamel. Enamel is a dead layer as it does not have any nerve or blood supply once formed. Enamel once formed cannot be reformed. Cavities extending below the enamel of the tooth usually approach the inner layer called Dentin. Dentin is often the cause of sensitivity experienced by the patient during the intake of hot or cold items.

Any cavity in the enamel takes almost 18 months to reach the underlying tooth structure, dentin. Once the enamel dentin junction is exposed the sensations are felt with the intake of hot or cold food items. Further progress of the lesion occurs if left unnoticed for a long duration of time. This may lead to the death of the tooth due to the involvement of the pulp chamber. Death of the tooth also presents with cold sensations being felt by the patient. 

Fractured teeth

Teeth sometimes undergo fracture due to loss of a substantial amount of structure which on loading /mastication may break down. Any accidental fall or a quarrel may lead to fracture of the front teeth. The fracture if exposes the inner layer of the tooth namely, dentin often causes the patient to feel uncomfortable due to hot or cold sensations. Mobility is also a possible outcome of the accidental fracture of the tooth.

Worn fillings

Tooth fillings often have a life span/shelf life till the time they can be retained in the prepared tooth cavity. Once lost, they leave the tooth exposed to further decay due to food accumulation. This decay increases the cavity size and often leads to sensitivity in the tooth.

Gum disease

Often gum problems are associated with sensations during intake of hot or cold foodstuffs. Calculus deposition /periodontitis /gum recession is caused due to erroneous brushing habits which aggravate the present situation causing loss of a tooth from the mouth. Deposition of plaque occurs due to wrong brushing habits which on calcification becomes a hard structure namely, calculus. Calculus is difficult to remove by general tooth brushing. Calculus if considered as the main cause of gum and bone recession which leads to exposure of root. Root exposure leads to sensitivity causing discomfort to the patient.

Worn tooth enamel

With the advancement of the age, there is wear and tear of tooth structure which is considered normal for an aged individual. This leads to exposure of the underlying dentin which is often the cause of sensitivity in tooth structure.

Exposed tooth root

In healthy teeth, a layer of enamel protects the crowns of your teeth—the part above the gum line. Under the gum line, a layer called cementum protects the tooth root. Underneath both the enamel and the cementum is a layer namely, dentin.

Dentin forms the major part of the tooth structure. Dentin is made up of tubules that contain fluid and nerve endings of the odontoblasts. Odontoblast is the primary regenerating cells lined up on the junction of pulp and dentin. Any injury to dentin due to a cavity or bacterial ingression is protected by the formation of reparative dentine by the odontoblasts. The nerve endings of the odontoblasts are the primary reason for the hypersensitivity experienced by the patient.