Dentin hypersensitivity is dental pain which is sharp and of short duration, arising from exposed dentin surfaces in response to stimuli, typically thermal, chemical, electrical, tactile, osmotic, evaporative and which cannot be ascribed to any other dental defect or pathology. The pain response varies substantially from one person to another.
Also known as sensitive dentin or dentin sensitivity.it can affect at any age, although those aged 20-50 years are more likely to be affected. Females are affected more than males. Most commonly effected teeth are premolars and canines.
What are the symptoms of dentin hypersensitivity?
- The pain is sharp and sudden, in response to an external stimulus.
- The most common cause is cold. Many people with dentin sensitivity reports pain upon application of a cold stimulus.
What causes dentin hypersensitivity?
Due to enamel loss
Tooth crown is composed of enamel, dentin and pulp. The outer layer is enamel. Enamel has no nerve supply. Dentin and pulp has nerve supply. After the loss of enamel denti8n is exposed. The exposed dentin leads to sensitivity. Causes of enamel loss are
Toothy wear: wear-tooth wear is defined as loss of dental hard tissue by a chemical or mechanical process not involving bacteria. Tooth wear facets are characterized as flat, round or sharp angled and polished surfaces on the Occlusal or incisal areas of the teeth and may be the result of excessive attrition of one tooth against the other. Tooth wear leads to enamel loss and exposes dentin. Severe tooth wear may extend to the pulp
Toothbrush abrasions: Improper tooth brushing techniques and high abrasive tooth pastes result in tooth brush abrasions
Abfraction: Abfraction lesions are small notches caused by stress on your teeth. Biting, chewing, clenching and grinding put pressure on your teeth. Over time, this pressure can cause cracks and splits in the outer layer of the teeth. This occurs in the thinnest part of your enamel near the gum line. In severe cases the dentin cementum layers of a tooth may become involved. Dentin may be exposed if a crack develops. In these cases the tooth may become sensitive.
Dietary erosion: Any food substance with a critical PH value of less than 5.5 can become a corrosive and demineralize the tooth structure creating erosion. Erosion of the dentin appears to bring about a rapid loss of the smear layer and the opening of dentinal tubules. The combination of abrasion and erosion can exacerbate dentin sensitivity quickly
Para functional habits: Ex: teeth Grinding in sleep. Para functional habits results in enamel loss and dentin exposure
Due to cementum loss
Cementum is a specialized calcified substance covering the root of a tooth. The root of the tooth is the part that extends into the upper or lower jaw bones. Cementum is not as hard and as white as enamel. Dentin is present under the cementum in the root. Due to loss of cementum dentin is exposed and leads to hypersensitivity. Causes of cementum loss are
Gingival recession: When cementum is exposed through gingival recession, it quickly undergoes abrasion by mechanical friction because of its low mineral content and thinness. The exposure of the deeper dentin can lead to problems such as extrinsic staining and dentin hypersensitivity
Periodontal diseases: cementum loss and gingival recession may occur due to periodontal diseases
Root planing: root dentin may exposed during root planing procedure
Periodontal surgeries: An increase in the root sensitivity occurred 1-3 weeks following therapy, after which it decreased.
Theories to explain dentin hypersensitivity:
- Direct innervation theory
Nerve fibers present within dentinal tubules initiate impulses when they are injured and cause dentinal hypersensitivity
- Odontoblast transducer mechanism
It was suggested that odontoblasts acted bas receptor cells mediating changes in the odontoblasts via synaptic junctions with nerves. This could result in sensation of pain from the nerve endings located in the pulpodentinal border
- Hydrodynamic theory
Most widely accepted theory is hydrodynamic theory. This was proposed by Gysi. Fluids within the dentinal tubules are disturbed either by thermal, physical or osmotic changes and that these fluid changes or movements stimulate baroreceptor which leads to neural discharge.
Prevention Techniques & Tips:
We all know that prevention is better than cure so follow these simple preventive measures to avoid dentin hypersensitivity.
- Decrease the consumption of acidic fruits and beverages
- Follow the proper brushing techniques
- Care during operative procedures
- Care during periodontal procedures.
- Elimination of Para functional habits.
Dentin Hypersensitivity Treatment:
Dentin hypersensitivity is relatively common and significant dental problem which can be successfully managed by a very wide variety of procedures, agents and formulations applied locally, either in office of at home. The treatment must act fast, be effective for long periods, be easy to apply, not irritate the pulp, not cause pain, not stain the teeth and be constantly effective.
The most inexpensive and efficacious first line of treatment for most patients is a tooth paste containing a desensitizing active ingredient such as Potassium nitrate or Stannous fluoride.
Formation of smear layer over exposed dentin
- Desensitizing tooth pastes
- Desensitizing chewing gums and mouthwashes.
Use of topical agents to occlude exposed dentin
- Calcium hydroxide paste
- Calcium Phosphate paste
- Dentin adhesives
- Potassium nitrate
- Silver nitrate
Ex: glass ionomer cement Composite
Lasers occlude the dentinal tubules by producing local changes around the exposed dentin. They also change the central pulp neuron.