Tooth sensitivity is the discomfort or pain to one or more teeth or associated areas that are triggered by hot or cold food or even by breathing cold air. Tooth sensitivity can be of two types. Sensitivity due to exposure of dentin: Dentin is covered by enamel above the gingiva and by cementum below the gingiva. When any of these is damaged, the dentin will be exposed and the pressure or the temperature changes affect the nerve endings which are within the pulp and close to dentin.
The damage can be due to:
a) Wearing off the enamel due to wrong brushing techniques. It is advisable to use a soft or medium brush with a bean size quantity of paste.
b) Poor oral hygiene: Poor oral hygiene creates plaque or tartar on the tooth surface which is one of the major reasons of dental caries.
c) No replacement of old dental fillings: Old dental restorations may get cracks over a period and this leads to leakage of fluids to the inner layer of teeth, which causes teeth sensitivity.
d) Periodontal diseases: Periodontal diseases if left untreated expose the tooth root and gradually the cementum wears off leading to dentin sensitivity.
e) Erosion: Long term use of aerated soft drinks causes erosion of teeth surface and exposure of dentin.
f) Wear and tear: Misalignment of teeth causes more biting pressure and gradual wear and tear of teeth surface.
g) Teeth whitening: Teeth whitening in individuals with exposed roots may cause dental sensitivity. Also, the use of low quality material and wrong techniques can corrode the enamel and exposes dentin.
Sensitivity due to exposure of pulp: Pulp is the most sensitive part of a tooth, and it consists of nerves and blood vessels. It is situated at the middle part of the tooth within the dentin. Unlike dentinal sensitivity, pulpal sensitivity does not affect more than one tooth.
The causes of pulpal sensitivity:
a) Dental fillings: Dental fillings done on a deep caries may cause pulp sensitivity if the caries is not excavated properly prior to filling. Or a recent root canal treatment without proper filling can cause tooth sensitivity.
b) Deep dental caries: Dental caries that is left untreated for long time extends to the pulp and cause tooth sensitivity.
c) Fractured tooth: A cracked or fractured tooth due to physical pressure or accidents may expose pulp and cause sensitivity to tooth.
d) Excessive biting pressure: Excessive biting pressure due to the irregular denture wears off the enamel and dentin and exposes the pulp.
Both dentinal and pulpal sensitivity reacts to temperature and pressure changes. Whatever may be the cause, teeth sensitivity is a 100 percent curable condition. If you are having a dentinal sensitivity, the dentist will perform scaling or cleaning of your teeth followed by a fluoride varnish application to protect the teeth. Pulpal sensitivity is cured by root canal treatment where the damaged nerve is removed and non reactive substances like gutta-percha will be placed over which a dental restorative filling is done.