Dentin hypersensitivityprepared by: Dr. Muneera Ghaithan
definitionIt’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
The neurophysiology of teeth• Both myelinated and unmyelinated axons innervated the pulp.• According to conduction velocities the nerve units can be classified into: Having conduction velocity A group > 2 m/s Having conduction velocity C group < 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 painMyelinated A fiber seems to be responsiblefor 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 theoryB. Odontoblastic theoryA. The hydrodynamic theoryB. Modulation theory
Neural theoryActivation to initial excitation ofthese nerve ending in dentinaltubulesnerve signals are conductedalong the parent primaryafferent 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 theoryThe theory assumed that odontoplastextend to the periphery. Stimuli Excite 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 theodontoblastic process is restricted to the innerthird of the dentinal tubules. Accordingly it seemsthat the outer part of the dentinal tubulesdoesnot contain any cellular elements but is onlyfilled with dentinal fluid.
The hydrodynamic theoryThis theory proposes that: StimuliDisplacement of fluid that exists in the dentinal tubules Activates the nerve endings present in the dentin or pulp
The displacement ofthe tubule contentsis rapid enough todeform nerve fiber inpulp or predentin ordamage odontoplastcell. Both of theseeffects appearcapable of producingpain.
Etiology and predisposing factorsThe primary underlying cause for DH is exposeddentin tubules Loss of covering periodontal structuresDentin may beexposed by: Loss of enamel
The area of recession that has developed due to a combinationof age-related changes, and history of gum disease (light blue).The dark blue area has a white filling which may have beenplaced there to treat dentine hypersensitivity.
Common Reasons for Gingival Recession1. 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 regionof cementum–enamel junction (CEJ), overlapping edge-to-edge not form a junction
Diagnosis The pain arising from DH is extremely variablein character, ranging in intensity from milddiscomfort to extreme severity. The degree of pain varies in different teeth andin different persons. It may emanate from one tooth or several teethand it is sometimes felt in all quadrants of the jaws
Most patients describe the pain arising fromDH as being rapid in onset, sharp incharacter, and of short duration ( the characterof pain doesnt outlast the stimulus). The pain is intensified by thermalchanges, sweet, sour, scratching the dentine.
Diagnosis and treatmentMaking the proper diagnosis is the first step inassisting your patients suffering from dentinhypersensitivity.
Management and Treatment• 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. Generally, the least invasive treatment method should be considered first.
Management and Treatment• Three principal treatment options:1. Dentinal tubules can be covered2. Dentinal tubules can be plugged3. Desensitization of the nerve tissues within tubules
Management and Treatment At-home treatments: • At-home treatments include desensitizing toothpastes or dentifrices 1. Desensitize the nerve a) Potassium Nitrate:interfere with the transmissionof the nerve impulsePotassium nitrate is commonlyused in toothpastes suchas Sensodyne or CrestSensitive as a remedy
Management and Treatment2. Plug (sclerose) the dentinal tubules:a) Strontium chloride and strontium acetateform mineralised depositswithin the tubule lumen andon the surface of the exposeddentine, they are used inSensodyne Original andSensodyne Mint toothpastes.b) Fluoride dentifricesNote the occlusion of the dentinal tubules,preventing the outward flow of fluid andsubsequent stimulation of nerve fibers.
Management and Treatment In-office procedures1- Desensitize the nerve: potassium nitrate2- partially obturate the dentinal tubulesa) stannous fluoride.b) potassium oxalate.c) strontium chloride.d) calcium compounds.
3- Tubule sealant• A) restorative resins.• B) dentin bonding agents.(GLUMA)4- Cavity varnish5- Laser
Management and Treatment 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