Tuesday, April 12, 2011

Sensitive Teeth

Sensitive Teeth

       Teeth become sensitive when the enamel wears out or gums recede exposing the nerve fibres to the external environment. Hypersensitivity means a signal that the dentin is exposed and the pulp is vulnerable to damage.

Dentinal hypersensitivity, or cervical dentinal sensitivity, is a significant clinical problem. It is defined as pain arising from exposed dentine typically in response to thermal, chemical, tactile or osmotic stimuli.

Tooth sensitivity is due to the wasting diseases of teeth, namely attrition, abrasion,erosion and abfraction. These diseases cause loss of tooth structure causing the dentin nerve fibres to get exposed, thus triggering sensitivity.Gum recession is also another reason for hypersensitivity.

Attrition is the loss of teeth structure by mechanical forces from opposing teeth. Attrition initially affects the enamel and, if unchecked, may proceed to the underlying dentin. Once past the enamel, attrition quickly destroys the softer dentin. Gradually it affects the whole teeth. Wear due to pressure from the other teeth is termed as attrition. The wear and tear usually initiates on the incisal or occlusal surfaces. 

At times hard toothbrushes, toothpicks, floss or any dental appliance wear the enamel. It generally affects the junction between the tooth and the gums - cementoenamel junction. The loss of tooth caused due to these external elements is described as abrasion. The teeth most affected due to abrasion are premolars and canines. 

Intake of various acidic foods and drinks act on the teeth causing erosion of the enamel. If left unchecked it proceeds to the dentin and then the loss of the entire tooth . Dental erosion the most common disease observed in children between 5- 17 years.
In general foods and drinks with a pH below 5.0 - 5.7 trigger dental erosion. Soft drinks such as fruit drinks, fruit juices and carbonated drinks such as colas cause erosion. Wine with pH value 3.0 - 3.8 too is observed to erode teeth. Other sources include chlorinated water from the swimming pool and regurgitation of gastric acids.


Sometimes a tooth under pressure face diverse forces at one time. One side of the tooth can be under tension while the other side under compression. This causes V-shaped depressions under tension and C-shaped depression under compression. The outcome is the loss of tooth from flexural forces termed Abfraction. 

This concept has not been supported by dental research but has been hypothesised. Research still continues to prove abfraction as one of the causes of tooth destruction.


Treatment would be the sealing of the exposed tubules using agents in severe cases using dental cements or composites.

It can also be reduced by using toothpastes specially made for sensitive teeth. Dentists also suggest application of fluoride sealant on the crown of the teeth. The sealant covers the exposed dentin and as a barrier against pain. If the above treatments are not effective then root canal therapy is recommended. This can make the tooth non vital to pain and protected by crowning it.

In severe cases the restoration of the tooth is done with dental cements or composites.