Tooth sensitivity is defined as an experience of pain or discomfort that is sharp, sudden, piercing or excruciating in nature that is felt deep into the nerve endings. The pain may affect the tooth constantly or intermittently depending on its cause and nature.

Generally tooth sensitivity is caused by receding gums and enamel damage that leads to dentinal tubules in the dentine layer to be exposed and hence sensitized. Therefore, thermal sensitization like hot or cold drinks intake may make you cringe in agony. Occasionally, sweet and sour foods or even breezy cold air could also inflict sudden sensitiveness.

Factors that leads to dentine exposure:

1. Post operative sensitivity (following dental procedures like fillings and crown placement)

Fillings which use amalgam, gold crowns, and inlays are common contributors to sensitivity as they are good temperature conductors. The scenario worsens if the cavity is deep and close to the nerve (pulp) causing intermittent pain.

Usage of composite (white) fillings could also cause post-treatment sensitivity as the placement of it could be rather technique sensitive which requires proper handling of dental materials. Besides, if the filling is left high in the bite and does not wear down quickly it will lead to further stress load and tooth became sensitive.

2. Fractured tooth

Cracked or broken teeth due to trauma contribute towards exposure of dentine and pulp which requires intervention to remedy the problem. If left unattended with pulp exposed, the bacteria from our mouth would enter the pulp causing inflammation and toothache.

3. Tooth wear

Tooth wear are considered as wasting diseases of the teeth that could present as we age.

It is categorized in three different types of wear which includes attrition, abrasion and erosion.

Attrition is loss of tooth substance as a result of tooth to tooth contact or friction. Normally, it it has presentation with physiological ageing but, however could manifest earlier with abnormal alignment of teeth and habits like teeth grinding.

Meanwhile, abrasion is a pathological (abnormal) wearing away of tooth substance by friction of a foreign body that is not present in our dentition. You will be surprise that wrong tooth brushing methods (e.g. brushing too hard) could recede our gums and hence exposing root surface cover that is commonly known as the layer of cementum. When the layer has been abraded off, underlying exposed dentine causes sensitivity. Other than that, habitual or occupational usage of pipe smokes and biting of needles n hair clips could also lead to exposure of dentine.

Lastly, erosion is a major contributor to sudden sensitivity as dietary acids from intake of fruit juices, carbonated soft drinks, and sucking of citrus fruits dissolves away tooth substance. This category also includes gastric reflux which erodes the posterior surfaces of teeth and is commonly seen in anorexia nervosa, bulimia, and chronic alcoholic’s patients. Tooth with erosions normally has symptoms of scooped out appearances.

4. Tooth whitening procedures

It is common that after getting your teeth bleached it may lead to a certain degree of temporary sensitivity depending on tooth whitening materials. Tooth whitening products normally has active materials like hydrogen peroxide and carbamide peroxide that has action of thinning and removing enamel and stains for a whiter opaque teeth.

5. Bruxism and teeth grinding

As mention above in attrition, teeth grinding is a habit that present when people are asleep at night and rarely in daylight. Bruxism is frequently cause by the risk factor of stress and therefore the excessive forces inflict the gnawing away of tooth structure exposing dentinal tubules for sensitization.

6. Teeth straightening

Also called as orthodontic treatment to correct misalignment of teeth, it causes tooth sensitivity with tooth movement created by pressure induced by appliances. Sometimes during the placement or activation of tooth straightening the slightest force could induce sensitiveness due to the uncovering of previously enclosed dentine sites and the movement of teeth.

7. Nerve degeration related sensitivity

When the nerve (pulp) is starting to die, it heightens its sensitivity to most symptoms. Thus, cold or hot substances which are consumed would illicit lingering pain that persists more than few seconds. Tapping or biting pressure induces tenderness or excruciating pain. Normally electrical test would be performed by dentist to indicate the vitality or whether the nerve is still alive a not. Depending on the degeneration a root canal treatment may or may not be indicated

In conclusion, sudden sensitivity is the sensitization of dentinal layer of tooth structure. The dentine has thousands of microscopic tubular structures which are 0.5-2 microns in diameter that radiate towards pulp’s nerve endings. Alteration or changes in the hydrodynamic flow of the plasma like biological fluid in these tubules trigger the mechanoreceptors in the nerve endings and translates to us as pain.

Hence, to avoid tooth sensitivity it is best for us to preserve our outer tooth structure the enamel with care and use desensitizing toothpaste if symptoms present.