1. Direct innervation theory
- first
theory to be put forward
- nerve
fibers present within dentinal tubules intiate impulses when they are injured
2. Odontoblast deformation theory/transducer theory
- nerve fibers are present only in the predentin and inner dentinal zones
- when pain inducing substances like pottasium chloride,acetylcholine are applied to exposed dentin,they fail to elicit painful response.
3. Hydrodynamic theory
- the most widely accepted
mechanism of action of dentin hypersensitivty , the hydrodynamic theory which was proposed by gysi in 1900 and validated by brannstrom in 1996
DIAGNOSIS
1. Complete history
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2. Clinical examination
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3. Radiographic examination
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signs and symptoms
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visual assesment
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rule out peri
apical lesion
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intensity
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physical assesment
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frequency and duration
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depth of periodontal pocket depth
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dietary changes
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percussion testing
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response to cold air
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DIFFERENTIAL
DIAGNOSIS
1.fractured restorations
2.fractured enamel exposing dentin
3.dental caries
4.post restoration sensitivity
5.cracked tooth syndrome
6.bleaching sensitivity
PREVENTION
1.diet counselling
regarding consumption of acidic fruits and beverages
2.correction of brushing technique
3.care during operative procedures
4.care during periodontal
procedures
MANAGEMENT
1.Desensitisation by
occluding dentinal tubules
a ) formation of smear layer over
exposed dentin
b ) use of topical agents to occlude
exposed tubules
• calcium hydroxide paste
• calcium phosphate paste
• silver nitrate
• fluorides
• fluoride iontophresis
• potassium nitrate
• varnishes
• dentin adhesives
c) placement
of restorations
• glass ionomer
cements
• composite resins
d) use of lasers
• co2 laser
• nd:yag,er:yag
laser
• he:ne laser
2. Desensitizing by blocking pulpal sensory nerves
a) potassium nitrate toothpaste
CALCIUM
HYDROXIDE
- it increases the remineralisation of
the exposed dentin thus reducing dentin permiability
- disadvantage : it
causes temporary occlusion of tubules
CALCIUM
PHOSPHATE PASTE
• it
reduces dentin hypersensitivity by blocking tubules and dentin permeability is
reduced
• available product – gc
tooth mousse
• it contains amorphous calcium phosphate and caesin phosphopeptide
SILVER
NITRATE
• it
reduses
fluid movement by precipitating protein or silver chloride within the dentinal tubules
• it
is not used nowadays as it stains dentin and also damages pulp and gingiva
STRONTIUM
CHLORIDE
- The
mode of action is linked to their ability to form mineralised deposits within
the tubule lumen
and on the surface of the exposed dentine that help prevent
transmission of the applied stimulus
FLUORIDES
•agents-sodium
fluoride,stannous fluoride or
acidulated phosphate fluoride.
•used
as mouth rinses,toothpastes or
topical application on exposed dentin.
•action
is by forming fluorapatite
within tubules which block fluid movement within dentin.
FLUORIDE
IONTOPHORESIS
• iontophoresis- it is a procedure in which ions of chosen medicament are driven into specific
tissues
by means of
electric current.
•flouride iontophoresis
transfers fluoride ions into dentin for desensitizing it. unit
has
• -positive electrode is placed on patients face
or arm
• -negative electrode is plastic tip placed around the tooth
• 2%
sodium fluoride is applied on the
exposed dentin and is transferred deep into the dentin on
activation of
the unit.
•it is
reported to provide long-term relief from hypersensitive dentin.
MANAGEMENT
varnishes
• they
act by forming a barrier over exposed dentin. This
reduces hypersensitivity as it reduces
dentin permeability. they provide only
temporary relief.
use of lasers
•they
occlude the dentinal tubules by producing local changes around the exposed
dentin
•they
also produce changes in central pulp neuron.
POTASSIUM
NITRATE
• potassium ion may depolarize the nerve
and prevent it from repolarizing, thereby, preventing it
from sending pain
signals to the brain.
• potassium ions are thought to diffuse
along dentinal tubules and decrease the excitability of
intradental
nerves by altering their membrane potential reducing nerve excitation, and the
associated pain.