Dentin hypersensitivity is a common condition caused by exposure of dentin tubules. Various theories have attempted to explain the transmission of pain signals, with the hydrodynamic theory currently favored. It proposes that fluid movement in dentin tubules stimulates nerve fibers. Clinical examination involves tactile, thermal, or chemical stimuli to provoke symptoms. Management focuses on occluding dentin tubules through agents, bonding resins, or lasers to block fluid flow. Further research continues to improve treatment approaches for this painful condition.
6. Few Terms…….
Definition: “Exaggerated response to a non noxious
sensory stimuli”
Addy & Urquart (1992) define….
Are pain and sensitivity related??
Chronic condition with acute exacerbations.
An enigma
7. Flashback
2000 years or more - Chinese… by the application of
‘Xiao-Shi’
3 rd century B.C-The Egyptian Medical Papyrus …red
and yellow vitriol and alum for “teeth that suffer”
875 A.D - Rhages ….treatment with astringent agents.
1678 Leeuwenhoek … “tooth canals in dentin”
9. 1855 - J.D.White …. movement of fluid in dentinal
tubules
1857 - Cartwright …. dentine sensitivity was
observed……… that some areas of the tooth were
"exquisitely sensitive" and a source of great discomfort.
10. 1898 - Henry H. Buchard-
agents to lower the pain perceptive centers of the
brain.
destroy or coagulate the dentinal protoplasm
local analgesic agents on the dentin.
1899 – George.F.Eames.. caused by erosion
1900 - Alfred Gysi - first to suggest relieving
hypersensitivity
11. 1941-Lukomsky-NaF..desensitizing obtundant.
1962- Brannstorm- Hydrodynamic Theory
1966….. Therapies
deposit an insoluble substance on the ends of the fibers
or nerves to act as a barrier
To stimulate secondary dentin formation.
In 1974… Hodosh…superior desensitizer….. Potassium
nitrate.
12. Etiology & Predisposing
factors
1. Loss of enamel
Abrasion
Erosion Attrition
Abfraction
2.Gingival Recession
13.
14. Scaling, Root planing, Periodontal Surgery……
Question arises whether tooth brushing with or without a
dentrifice will expose dentinal tubules
Role of plaque – important factor
Role of saliva and bacterial contamination..
Loyn et al(1991)..effect of some proprietary mouth rinses
on dentin smear layer.
15. Nerve fibers
The dental pulp is richly innervated ….
Myelinated … Non myelinated
A fibers … C fibers
B fibers…
A-ά… proprioception, A-β…touch & pressure, A-γ…motor function
to spinal nerves and A-δ fibers…pain, temp & touch.
16.
17. A-delta and C-fibers sub odontoblastic plexus…..
A-δ…. Brief, sharp, well localized pain …. Dentinal
hypersensitivity.
C fibers… poorly localized pulpal pain.
18. Theorie
s
Direct stimulation
Odontoblastic transducer mechanism
Gate-control theory and vibration
Hydrodynamic mechanism
20. Anderson’s explanation
No nerve elements….
Receptor mechanisms in dentin that could be stimulated
indirectly…no direct stimulation… barrier.
This theory is deficient because neural elements have not
been shown to extend into the peripheral half of-the dentin.
(Forrest et al 1988)
22. Synaptic like relation b/n the terminal sensory nerve endings
& odontoblastic processes.
No evidence of acetylcholine
Proponents of dentinal receptor mechanism…. Odontoblasts
has special sensory function and that a functional complex
with the terminal sensory nerve endings … excitatory
synapse…neuro sensitive complex
23. Drawbacks
Why dentin continues to be sensitive, despite destruction
of odontoblast layer?
Also does not explain why protein precipitation does not
decrease sensitivity of dentin to osmotic stimuli.
Abandoned…. Failure to establish a synaptic relation
between the odontoblasts and the pulpal nerves.
24. Gate control theory and vibration
When the dentin is irritated, all of the pulpal
nerves become activated from the vibrations.
As the low-intensity "pain gates" from the larger
fibers are closed, the high-intensity "pain gates"
from the smaller fibers are enhanced.
25. Drawbacks
:
Little to explain how pain responses from the dentin are
transmitted and perceived by the nerve endings of the pulp-
only how they may be centrally interpreted.
26. Hydrodynamic Theory (Brannstrom)
This idea of fluid movement within the dentinal tubules is the
basis for the transmission of sensations according to the
hydrodynamic theory.
31. Alternative mechanism (Modified
Hydrodynamic theory)
Application of various chemical solutions
Raising the intratubular potassium content,
Interdental nerves less excitable to further stimuli by
depolarizing the nerve fiber membrane.
34. Physiologic & Pathologic
pulpal defense mechanisms
Formation of secondary dentin
Peritubular dentin calcification…
Natural occlusion of the dentinal
tubules
Plaque adhesion and salivary
occlusion of the surface of the dentin
39. Tactile Method
Using a Yeaple probe…. Compact hand
piece that contains an explorer tine …
electromagnetic field.
Scratchometer
Courtesy : Kleinberg{1988}
41. Thermal Sensitivity
An air thermal device devised by Dr. K.C. Yeh used a
temperature controlled stream of air as the stimulus.
Air was heated to 1000F close to temperature of the
mouth. Its temp was then reduced until the subject felt
pain or discomfort.
Drawbacks : Moisture content
43. Electrical Sensitivity
Pain response from both non sensitive and sensitive teeth.
Lower organic resistance material to enamel, cementum and
dentine.
Access of electrical stimulus via open tubules
45. Osmotic Method
An osmotic method….. McFall and Hamrick(1987)
Fresh saturated solution of sucrose and allowing it to
reach room temperature
Solution is then applied to the root surface of the tooth
…..in place for 10 sec
46. Popularized by Anderson and his colleagues
Effective because the chemical activity of water in these
solutions is less than the chemical activity of water in
dentinal fluid
Calcium chloride excites intra dental nerves owing to
osmotic movement of fluid
Sodium chloride excite nerves owing to indirect osmotic
effects on superficial dentin & direct effects on intra
dental nerves in deep dentin.
50. Current approaches to the
Management
1.Fluid formation of smear layer
2.Topical application
3.Impregnation of tubules
4.Dentin bonding agents
51. Most agents that are effective in reducing dentinal
hypersensitivity are also effective in partially occluding
the dentinal tubules
Greenhill and Pashley found potassium nitrate to be
ineffective, but it is effective as a desensitizing agent.
Most in-office procedures are aimed at obturating the
tubules
52. Mechanism of actions of desensitizing
agents
The methods of tubule occlusion are,
1. Formation of calcium over sensitive tubules
2. Formation of intra tubular crystals from salivary mineral
3. Formation of intra tubular crystals from dentinal fluid.
4. Progressive formation of peritubular dentin
5. Invasion of tubules by bacteria
6. Formation of intratubular collagen plugs
53. 7. Formation of irritation dentin
8. Leakage of large plasma proteins into tubules.
9. Formation of smear layer by brushing, use of tooth
picks etc
10. Resin impregnation or covering
11. Topical application of Calcium hydroxide, sodium
fluoride and oxalate
12. Restorations
58. Corticosteroids
Anti-inflammatory effect of glucocorticoids …. decrease
dentinal sensitivity
Mjor and Furseth …..
Use is based on the assumption that hypersensitivity is
linked to pulpal inflammation
59. Burnishing of dentin
Tooth pick or "orange wood stick …
Pashley et al(1987)….Reduced fluid movement by 50% to
80%
61. Silver nitrate
Powerful protein precipitant
Precipitated in solution with formalin or eugenol
It may cause pulpal inflammation in shallow cavities.
62. Calcium hydroxide
Block dentinal tubules or promote peritubular dentin
formation
Brannstrom (1976) … constriction of the dentinal tubules…
depth of 0.1mm
Following periodontal surgery, Jorkjend and
Tronstad(1972)……
63. Fluoride
First proposed …. Lukomsky (1941)
Bolden and Hezen et al have indicated that sodium
monofluorophosphate dentifrice…. Effective
Ranouse and Ash….. 0.76% of sodium
monofluorophosphate
64. Mechanism of action….
Clement and Hoyt and Bibby found sodium fluoride
very effective in reducing dentinal hypersensitivity
It may produce severe pulpal inflammation when
applied to dentin.
65. Acidulated sodium fluoride
Laufer et al(1981) ……Concentration of fluoride in
dentin … greater
No difference after samples were washed with synthetic
saliva
A small fraction of the fluoride initially deposited on the
root surfaces was retained in the insoluble apatite form.
66. Sodium silico fluoride
Bhatia …. saturated solution of sodium silico fluoride
for 5 min …..potent than 2% solution of NaF in
desensitizing painful cervical areas of teeth.
Everett et al…. that silicic acid forms a gel with the
calcium of the tooth, thus producing an insulating
barrier
67. Stannous fluoride
Blank and Charbeneau(1986) advocated burnishing a 10%
solution of stannous fluoride
Ellingsen and Rolla(1987) examined SnF2 treated dentin
surface using S.E.M. and observed a dense layer of tin and
fluoride containing globular particles blocking the dentinal
tubules.
Blong and associates(1985)…0.4% SnF2 gel effective
68. Fluoride Iontophoresis
Iontophoresis …
Iontophoresis of fluoride … controversial
Induction of Secondary dentin formation by Iontophoresis
…. Murthy et al
Lefkowitz et al reported on the pulpal response to 1%
sodium fluoride Iontophoresis
69. Gangarosa recommends that teeth be isolated with plastic
strips and cotton rolls rather than a rubber dam
Induction of parasthesia on odontoblast process by
Iontophoresis …Gangarosa and Park (1978)
produce parasthesia by a direct effect on the
odontoblastic process or by alteration of the sensory
mechanism of pain conduction
Singhal(2005)……
70.
71. Nd-YAG Laser treatment
Effective in reducing dentine hypersensitivity to cold
stimuli.
The mechanism of action has yet to be confirmed
Lier et al (2002)…Nd:YAG laser…not significant
Shwartz et al (2002)… Er:YAG laser…. Dentin
Protector
73. Oxalates
Calcium ions in the dentinal fluid to form insoluble
calcium oxalate crystals
Formaldehyde
Formalin is an agent … control of dentin
hypersensitivity
During late 1940s, Emoform tooth paste was introduced.
74. Resins and Adhesives
Brannstrom and Nordenvall ….. impregnating it with
resin (the unfilled dentin bonding agent)
Bowen & Cobb … composite resin bonded to dentin
decreased dentin permeability.
Objective-
75. Javid & co workers… 6 week study …. Isobutyl
cyanoacrylate with 33% of NaF paste….
Immediate desensitization..
Sensitivity slowly returned
Glass ionomer cement…. Hydrophilic
GLUMA…dentin bonding system …includes 5%
glutaraldehyde primer & 35 % HEMA
80. References
DCNA on Tooth hypersensitivity 1990, 34:3
Text book of Clinical Periodontology –Carranza
Clincal Periodontology & Oral Implantology –
Jan Lindhe
Text book of conservative dentistry – Sturdevent
Dentinal Sensation and Hypersensitivity A
Review of Mechanisms and Treatment
Alternatives (Louis H. Berman) Journal of
Periodontology 1985 Apr (216 - 222):
Role of dentin bonding agent in reducing
cervical dentin hypersensitivity – JCP 1998
81. JCP 2002 “desensitizing effects of an Er:YAG
laser on hypersensitive dentin”
JISP 1997… Comparative evaluation of Gluma
primer & 10% pot nitrate in treating cervical
dentin hypersensitivity.
JCP 2002.. Treatment of dentin hypersensitivity
by Nd:YAG laser
JP 2001…. Efficacy of 3% pot nitrate
desensitizing mouthwash in the treatment of
dentin hypersensitivity.
Dentine Hypersensitivity: new perspectives on
an old problem. International Dental Journal
(2002) 52, 367–375