Dentin Hypersensitivity Flashcards
(22 cards)
Dentine sensitivity is
clinically described as an exaggerated
response to application of a stimulus to exposed dentine.
True hypersensitivity can develop due
to pulpal inflammation and can present the clinical features of
irreversible pulpitis, i.e., severe and persistent pain, as compared with typical short sharp pain of DH
Dentine hypersensitivity is characterized by
short, sharp
pain arising from exposed dentine in response to stimuli,
typically thermal, evaporative, tactile, osmotic or chemical and which cannot be ascribed to any other
dental defect or pathology
DH is a painful clinical condition with an incidence
ranging from
4 to 74%.
slightly higher incidence of DH is reported in
females than in males.
While DH can affect the patient of any age, most affected patients are in the age group of
20–50 years.
pathogensis
DH develops in two phases lesion localization and lesion
initiation.
➢Lesion localization occurs by loss of protective
covering over the dentin, thereby exposing it to
external environment.
➢lesion initiation: . It occurs after the protective
covering of smear layer is removed, leading to
exposure and opening of dentinal tubules.
Mechanism
Three major mechanisms of dentinal sensitivity have
been proposed
➢Direct innervation theory.
➢Odontoblast receptor.
➢Fluid movement/hydrodynamic theory.
Direct innervation theory:
The nerve endings theory that claimed that sensory nerve endings migrate inside the dentinal tubules and are responsible for such sensation. However, no
sound evidence has been reported to document the validity of these theories.
Odontoblast receptor.
The odontoblasts receptor theory which proposed that
the odontoblastic process by itself acts as a sensory
receptor transmitting sensory sensation through the
odontoblast to the underlying nerve endings in the cell
free zone.
Fluid movement/hydrodynamic theory.
proposed that non noxious stimuli by oral environmental
factors on the exposed vital dentin surface may lead to
upwards movement of the dentinal fluid towards the
open dentinal tubule end (which has become connected
to the oral cavity) leading to tension on the nerve endings at the pulp surface causing typical dentinal
pain.
Causes
➢Periodontal disease and gingival recession.
➢Cracked teeth,
➢Non caries lesion (erosion, abrasion, abfraction)
➢Tooth fracture may cause hypersensitivity.
➢removal of cervical cementum during scaling and root
planing, or extreme tooth brushing.
➢ Regurgitation by patients with bulimia produces acid
exposure, and subsequent brushing can lead to loss of
tooth structure.
➢Non-incremental placement of composite restorations
(tensile stress on cavity walls)
➢Torque on abutments of long-span bridges .
Cause of hypersensitivity during operative procedure:
➢Dull cutting instrument.
➢Heat generation (cause)
Non effective coolant(copious in amount, multidirectional,
and air spray) , Excessive pressure during cutting.
➢Dentin desiccation(due to repeated blast of air the
operator may overlay dehydration
Cause of postoperative hypersensitivity after placement of composite
➢Deep cavity preparation
➢ Age of patient : Young patients have larger pulp chambers and larger dentinal tubules, making it more
likely that their teeth would be more sensitive to hydrodynamic stimuli .
➢ Age of patient : Young patients have larger pulp
chambers and larger dentinal tubules, making it more
likely that their teeth would be more sensitive to
hydrodynamic stimuli .
➢High occlusal point and masticatory stress.
➢BIOCOMPATIBILITY OF MATERIALS
Measure that can reduce postoperative hypersensitivity after placement of composite
Importance of isolation:
➢ Etched enamel and
dentine should be
protected from saliva and
other fluids.
➢Rubber dam application is
an important isolation
measure.
Minimal invasive tooth preparation:
It’s important to preserve maximum amount of natural tooth
substance.
Avoiding the tendency of over drying (desiccating) dentine
Use of liner or base in deep
cavities:
As the cavity increases in depth
there is alarge need for
protective methods (liner and
base) .
RGIc can reduce the dentine
permeability.
➢Directional curing technique
➢Using light transmitting matrix and wedges:
Will help cure the deep cervical increment in class II
restorations.
➢THE USE OF SILORANE (LOW SHRINKAGE MATERIALS)
New silorane containing materials provides less polymerization stress
Examination
techniques such as pure air, pure water, are used in
order to reconstruct the stimulating factors and to
determine the degree of pain of the patient.
Classification of desensitising agents
Mode of administration: -in office - at home
MOA
-• Those who disturb the neural response to
pain stimulus.
• Those who block the flow of tubular liquid
and therefore lead to occlusion of
dentinal tubules.
➢At-home therapy:
include tooth powders, tooth
pastes, mouth washes and chewing gums.
➢Nowadays, most of the desensitizing toothpastes
contain potassium salts such as potassium chloride,
potassium citrate, and potassium nitrate.
➢The studies have revealed that blocking the axonic
action of the intra-dental nerve fibers and decrease
the excitability of the tooth.
➢About 2-4 weeks after at- home therapies, the degree of
DH would be reinvestigated. If the pain still existed, the
patient should
start the next phase of the therapy; in-
office therapy.
➢In-office therapy
Theoretically, in-office therapy of DH should lead to
immediate relief of the pain.
Disturbing the transmission of nerve impulses agent
1. potassium salts (potassium nitrate)
2. Laser
can be placed into the group of disturbers of nerve
impulse transmission.
➢Occluding dentinal tubules agents:
- Fluorides:
✓Fluorides precipitate calcium fluoride crystals inside
dentinal tubules, and thus decrease dentinal
permeability. - Oxalate :Oxalates can occlude dentinal tubules and reduce
permeability of dentine, up to 98% Mode of action
Complication: Potassium oxalate can lead to some digestive disorders so
it should not be used for a long.
- Varnishes :Copal varnish is used to cover the exposed
dentine.
However, its effect remains for a short period of time and
it needs to be applied several times . - Adhesive resins can effectively seal dentinal tubules
through forming a hybrid layer - Bioglass:
✓Its main component is silicate which acts as a nucleus for
precipitation of calcium and phosphate.
✓Scanning electron microscopic(SEM) analysis has shown
that the application of bioglass causes the formation of
an apatite layer which further leads to the occlusion of
dentinal tubules. - Portland cement
Some researchers have shown that silicate cement
which is derived from Portland cement can be
effective in DH management and help the occlusion of
tubules through Re-mineralization - Casein-phosphopeptide-amorphous calcium
phosphate - Laser:
the effect of laser on the treatment of DH is
different , based on the type of laser and therapeutic
parameters such as the laser’s length of beam; the amount of
time spent on the use of laser and the intensity of laser .
1. Occlusion through coagulation of the proteins of the fluid
inside the dentinal tubules
2. Occlusion of tubules through partial sub-melting
3. Discharging of internal tubular nerve
(CPP)-(ACP)
Finally, Considering….. in cases where at-home and in-office treatments were not effective.
RCT
