Tooth hypersensitivity

Dentin hypersensitivity

prepared by: Dr. Muneera Ghaithan

Dentin hypersensitivity

definition

It’s defined as sharp ,short pain arising from exposed dentin in response to stimuli typically thermal, chemical, tactile or osmotic and which can not be ascribed to any other form of dental defect or pathology.

It’s a symptom complex rather than a true disease

Mechanism of Dentinal Sensation

The neurophysiology of teeth

• Both myelinated and unmyelinated axons innervated the pulp.

• According to conduction velocities the nerve units can be classified into:

A group

C group

Having conduction velocity > 2 m/s

Having conduction velocity < 2 m/s

• Aδ fibers ( C.V≈6-30 m/s) are responsible for sharp better localized pain.

• While C fibers are considered responsible for dull radiating pain

Myelinated A fiber seems to be responsible for dentin sensitivity.

• It is well known even the most peripheral part of dentin is sensitive. However, varying opinions have been presented on the mechanism of intradental nerve activation in response to external irritation.

Mechanism of dentin sensitivity

Theories of dentin sensitivity:A. Neural theory

B. Odontoblastic theory

C. The hydrodynamic theory

D. Modulation theory

Neural theory

Activation to initial excitation of these nerve ending in dentinal

tubules

nerve signals are conducted along the parent primary afferent nerve fibers.

Dental nerve branch.

brain

a recent neuroanatomic studies -Byer (1984) have shown that only the inner 100 to 200 µm of dentin is innervated, indicating that the pain

sensations induced by stimulation of superficial dentin cannot be a result of direct irritation of

nerve ending.

Odontoblastic theory

The theory assumed that odontoplast extend to the periphery.

StimuliExcite the process or body of

odontoplast.

The membrane of odontoblasts come into close apposition with that of the

nerve ending in the pulp or in D.T.

The odontoblast transmets the excitation of these nerve endings

Thomas (1984) indicated that the odontoblastic process is restricted to the inner third of the dentinal tubules. Accordingly it seems that the outer part of the dentinal tubules doesnot contain any cellular elements but is only filled with dentinal fluid.

The hydrodynamic theory

This theory proposes that:

Stimuli

Displacement of fluid that exists in the dentinal tubules

Activates the nerve endings present in the dentin or pulp

The displacement of the tubule contents is rapid enough to deform nerve fiber in pulp or predentin or damage odontoplast cell. Both of these effects appear capable of producing pain.

Mathews et al (1994)

Etiology and predisposing factors

The primary underlying cause for DH is exposed dentin tubules

Dentin may be exposed by:

Loss of covering periodontal structures

Loss of enamel

 The area of recession that has developed due to a combination of age-related changes, and history of gum disease (light blue). The dark blue area has a white filling which may have been placed there to treat dentine hypersensitivity.

Common Reasons for Gingival Recession

1. Inadequate attached gingiva2. Prominent roots3. Toothbrush abrasion4. Pocket reduction periodontal surgery5. Oral habits resulting in gingival laceration, i.e.,

traumatic tooth picking eating hard foods6. Excessive tooth cleaning7. Excessive flossing8. Gingival loss secondary to specific diseases, i.e.

periodontitis, herpetic gingivostomatitis9. Crown preparation

Causes of loss of enamel:

Erosion .

Attrition.

Abrasion.

anatomical characteristics in the region of cementum–enamel junction (CEJ),

edge-to-edgeoverlapping not form a junction

Diagnosis

The pain arising from DH is extremely variable in character, ranging in intensity from mild discomfort to extreme severity.

The degree of pain varies in different teeth and in different persons.

It may emanate from one tooth or several teeth and it is sometimes felt in all quadrants of the jaws

Most patients describe the pain arising from DH as being rapid in onset, sharp in character, and of short duration ( the character of pain doesn't outlast the stimulus).

The pain is intensified by thermal changes, sweet, sour, scratching the dentine.

Diagnosis and treatment

Making the proper diagnosis is the first step in assisting your patients suffering from dentin hypersensitivity.

Differential diagnosis

1. Chipped teeth.2. Fractured restoration.3. Restorative treatment.4. Dental caries.5. Cracked tooth syndrome.6. Other enamel invaginations.

• Addressing any underlying causes of dentin hypersensitivity is the first step in successfully managing the condition. 

• Educating the patient on the causes and management of dentinal hypersensitivity.

• Treatment options include both in-office procedures and at-home care.

Management and Treatment

Generally, the least invasive treatment method should be considered first. 

• Three principal treatment options:

1. Dentinal tubules can be covered

2. Dentinal tubules can be plugged

3. Desensitization of the nerve tissues within tubules

Management and Treatment

At-home treatments:• At-home treatments include desensitizing

toothpastes or dentifrices

1. Desensitize the nervea) Potassium Nitrate:

Management and Treatment

interfere with the transmission of the nerve impulsePotassium nitrate is commonly used in toothpastes such as Sensodyne or Crest Sensitive as a remedy

2. Plug (sclerose) the dentinal tubules:

a) Strontium chloride and strontium acetate

form mineralised deposits within the tubule lumen and on the surface of the exposed dentine, they are used in Sensodyne Original and Sensodyne Mint toothpastes.

Note the occlusion of the dentinal tubules, preventing the outward flow of fluid and subsequent stimulation of nerve fibers.

Management and Treatment

b) Fluoride dentifrices

In-office procedures1- Desensitize the nerve: potassium nitrate

2- partially obturate the dentinal tubules a) stannous fluoride. b) potassium oxalate. c) strontium chloride. d) calcium compounds.

Management and Treatment

3- Tubule sealant• A) restorative resins.• B) dentin bonding agents.(GLUMA)

4- Cavity varnish

5- Laser

Patient education• Causes of dentinal hypersensitivity• Instructions on tooth brushing technique and when

to brush.• Advice on toothbrush type - avoid medium and

hard bristles• Advice on appropriate use of toothpaste• Advice on technique for interdental cleaning• Dietary advice• Hypersensitivity associated with tooth whitening

Management and Treatment

Thank you