dentinal hypersensitivity, theory, treatment

1. DENTINAL HYPERSENSITIVITY….

2. Contents.
 Introduction
 Definitions
 Etiology
 Mechanism of dentin sensitivity
 Theories
 Clinical considerations
 Methods of measuring hypersensitivity
 Management of hypersensitivity
 Summary & conclusion

3. Introduction.
 The term dentine hypersensitivity has been used for many
decades to describe a common painful condition of the teeth.
Despite this there are many gaps in our knowledge concerning
dentine hypersensitivity.
 It is perhaps not surprising therefore that one can still have
sympathy with statement made in 1987 by Johnson and Co-
workers that dentine hypersensitivity is an Enigma, being
frequently encountered yet ill understood.

4. Definition.
Dentine hypersensitivity is defined as 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.
Dowell and Addy 1983

5. Prevalence
 15-18% of the general populations;
 72-98% - In periodontal patients
 Age incidence: – 20-40 yrs peak; range 20-50 yrs.
 (Reasons – appearance and progression of gingival recession.)
 Gender: - Proportionately more females affected than males.
 Reasons: Related to the better oral hygiene of females compared with
male
 Differences in diet – favoring healthy but often acidic foods and drinks in
females.
 Either periodontal disease and / or periodontal treatment predisposed to
dentine hypersensitivity, presumably through both having effects on
dentine and gingival recession.

6. Distribution
 Buccal cervical area of teeth
 Reasons – site of pre-dilection for gingival recessions and the area
where enamel is the thinnest.
 Most commonly affected are canines and Ist premolars, then incisor
and 2nd premolars, least often molars.
 Show a negative co-relation with plaque scores recorded by site.
 Significantly greater proportions of left side tooth sensitivity
compared with their right contralateral tooth types.

7. Etiology
Two processes need to occur to arise dentine hypersensitivity.
 Lesion localization
 Lesion initiation
dentine has to become exposed.
 A. LESION LOCALIZATION:
Causes:
 Enamel loss
 Gingival recession

8. Enamelloss
Attrition. Abrasion.

9. Erosion.
• dietary
• environmental
Extrinsic acids
Intrinsic acids

10. Abfraction.

11. Other reasons.
 Improper instrumentation
 Enamel and cementum do not meet at the CEJ

12. Gingivalrecession
Cause:
 Tooth brushing
 ANUG and ANUP,
 Self- inflicted injury,
 Periodontal disease,
 Periodontal surgical and non-surgical
procedures,
 Dehiscence / fenestrations.

13. B. LESION INITIATION
 Require opening of dentinal tubules
 Tooth paste remove the smear layer
through abrasive and detergent actions
 Erosive agents, particularly acid dietary
fluids readily expose tubules
 Most soft drinks, some alcoholic
beverages and yoghurt all readily
remove the dentine smear layer after a
few minutes of exposure.
 Erosion causes bulk loss of dentine and
surface softening, which is very
susceptible to physical insults.

14. Mechanism of action
The neural theory, gate
control theory
The odontoblastic
transduction theory
The hydrodynamic theory

15. Direction neural stimulation
 According to this theory the dentinal tubules innervated by
nerves, which extend upto 100 microns along the dentinal
tubules.
 Whenever there is injury to these dentinal tubules, the stimuli
reach the nerve ending in the inner dentine.
 The stimulated nerve causes hypersensitivity.
 Since histological examination shows the dentinal tubules does
not contain any nerve endings, this theory is not accepted

16. Gate controltheory.(seltzer)
• A.k.a. vibration theory
• Irritated pulpal nerves get activated & larger myelinated fibres
accommodate these sensations.
• But smaller C fibres tend to be maintained hence high intensity
gates remain open
• Causing pain

17. 2. Transduction theory
 Membrane of the odontoblast process is excited by the stimulus
and the impulse is conduct to the nerve ending in the inner
dentine i.e. pre-dentine, odontoblast zone and pulp.
 Not popular theory since there is no neurotransmitter vesicles in
the odontoblast process to facilitate the synapse or synaptic
specialization.

18. 3. Hydrodynamic theory
 Ist proposed Gysi – 1900,)
(Brannstrous 1963,67.)
Rapid shifts of the fluids within the
dentinal tubules, following stimulus
application, result in activation of
sensory nerves in the inner dentin
region of the tooth

20. Clinical assessmentof dentine
hypersensitivity
 Subjective Evaluation

21. 1. Verbal rating scale is a simple descriptive pain scale which
includes the following:
1 – Mild discomfort
2 – Marked discomfort
 0 – No discomfort


 3 – Marked discomfort that lasted for more than 10 seconds

22. 2. Visual analogue scale is a line 10 cm in length,
the extremes of the line representing the limits
of pain, a patient might experience from an
external stimulus.
3. McGill pain questionnaire – the patient is
shown 20 sets of words and asked to select a
word from each set which best describes the
present pain experience.

23.  Objective assessment

24. Mechanicalor tactilestimuli
 Pass a sharp dental explorer… grade the response …..scale 0 – 3
 Collins used a no 23 explorer
 Simple yet effective
 5 – 10 gm of force…Tip of the explorer … 500/nm2…
compression and deformation of dentin.
 Incorporating a calibrated strain gauge in the explorer.
 Using a Yeaple probe…. Compact handpiece that contains an
explorer … electromagnetic field.

25.  Hand held scratch device… Dr Kleinberg
 Torsion gauge
 Sharp explorer like probe
 Indicator …Records the force of displacement in centinewtons
 Probed at CEJ
 A tooth that fails to respond at 80 centi-newtons is non
sensitive.

26. Scratchdevice

27. Thermal Sensitivity
 Directing a burst of warm temperature air from a dental syringe
onto the test tooth
 One second blast from the air syringe …. temperature is b/n 650
and 700F and at a pressure of 60 psi
 0 - No discomfort
 1 - Mild discomfort, but no severe pain
 2 - Severe pain when stimulus is applied
 3 - Severe pain occurs and persists even after removal of stimulus

28.  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.
 The Yeh device had a disposible plastic tip, and air emitted at 10
psi could be adjusted to between 1000 and 700F within about 2
minutes.

29.  Cold water testing: varied temperature of 15 ml of water is rinsed.
 Thermo-electric device (Biomat-thermal probe)
 It provides a continuous application of heat/cold.
 Consists of small probe tip to which thermistor is attached. This
thermistor measures the temperature at the probe tip.
 A current flow is used to regulation air temperature either by
increasing or decreasing the current flow in range of 12oC- 82oC
 It is preset at temperature of 37.5oC. It can be used for heat and cold
testing by increasing or decreasing the temperature by IoC.
 Ice – stick.
 Heat or cold air.
 Ethyl chloride.

31. Electrical stimulation
Electrical pulp tester
 Is a battery operated, producing pulses of direct current. The intensity of
the output voltage may be increased by pre-setting various numbered
gradations (0-10) on a thumb wheel.
Dental Pulp Stethoscope
 Developed by Stark et al (1977)
 Consisted of a digital readout sensitive voltameter connected to a digital
printer teeth was activated by push button control. A conventional
battery powered electrical pulp tester was attached to the Voltameter.
 The stimulus intensity was measured in volts.
 The pulp test lip is placed on the gingival 1/3rd of enamel and tooth
stimulated. A electrolytic gel with a pH of 5.4 – 5.6 is used.
 When patients feel tingling warm sensation, it is switched off and voltage
is read in digital read out. 15 volts and above- range of non sensitivity

32. Starkinstrumentfor electricalstimulation

33. Chemical / osmotic stimulation
 Hypertonic solutions. Eg. Sodium chloride glucose, sucrose and
calcium chloride.
 The use of chemical solution is complicated, because the solute in
solution diffuses into the dentine fluid. On repeated applications,
the osmotic pressure difference between the tubular fluid and the
applied fluid will decrease and reduce the effect of the solution as
our osmotic stimulus.
 Toavoid this, long time intervals must be allowed between the
applications of the solutions.
 Practically least preferred.

34. DifferentialDiagnosis
 Cracked tooth syndrome.
 Fractured restorations.
 Chipped teeth.
 Dental caries.
 Post-restorative sensitivity.
 Teeth in acute hyper function.

35. MANAGEMENT

36. Classification
 According to Scherman A and Jacobeen – 1992.
 Based on chemical and physical properties as follows.
Physical agents
Composites
Resins
Varnishes
Sealants
Soft tissue grafts
Glass inomer cement
Lasers
 Chemical agents
 Corticosteroids
 Silver nitrate
 Strontium chloride
 Formaldehyde
 Potassium nitrate or oxalate
 Fluorides
 Sodium citrate
 Iontophoresis with 2% NaF

37. B. IN-OFFICE PRODUCTS
 1. Treatment agents that do not polymerize.
a. Varnishes / Precipitants
 Shellacs
 5% NaF varnish
 1% sodium fluoride, 0.4% stannous fluorides
 3% mono-potassium-monohydrogen oxalate
 6% acidic ferric oxalate
 Calcium phosphate preparations.
 Calcium hydroxide.
b. Primes containing HEMA (Hydroxy ethyl methacrlate)
 5% glutaradehyde
 35% HEMA in water
 II. Treatment agents that undergo setting or polymerization reactions.
 Conventional glass ionomer cement.
 Resin-modified glass ionomer cement / Compomers
 Adhesive resin primers
 Adhesive resin bonding system.
 III. Use of mouth guards.
 IV. Iontophoresis.
 V. Lasers.

38. Mechanisms
 The most likely mechanisms of action is the reduction in the
diameter of the dentinal tubules so as to limit the displacement of
fluid in them.
According to Trowbridgeand Silver (1990) this can be attained by
 Formation of a smear layer produced by burnishing the exposed
surface.
 Topical application of agents that forms insoluble precipitates
with in the tubules.
 Impregnation of tubules with plastic resins.
 Sealing of the tubules with plastic resins.
 Act via precipitates of crystalline salts on the dentine surface,
which blocks dental tubules.
 Desensitizing agents are effective when used continuously for a
period of at least 2 weeks.

39. A. Home use products

Rationale.
Home use ‘over the counter’ desensitizing products appear to
be the most realistic and practical means of treating most
patients with tooth dentine hypersensitivity and should be the 1st
step in routine management.
Several reasons exit to prescribe these products.
 They are readily and widely available in pharmacies
 The products are cost effective.
 The ‘over the counter’ products an simple to use and non-invasive
 The habit of tooth brushing is almost universal the patients are
not required to do anything.

40. Strontiumchloride
 Dentifrice containing 10% strontium chloride hexahydrate
as the desensitizing agent
 Sensodyne tooth paste was formulated with strontium
chloride hexahydrate in 1961
 In vitro studies report that strontium chloride only slightly
reduces dentinal fluid flow, the occurrence thought to be
produced by the abrasive filler occluding the tubule
orifices.
 Skurnick in an uncontrolled study, found that it decreased
dentinal sensitivity short term in 93% of cases.
 However, Anderson and Matthews found it ineffective as
a densitizing agent.
 Possible detrimental pulpal effects of strontium chloride
have also been suggested.
 Minkoo et al regular at-home use of a dentifrice
containing 10% strontium chloride hexahydrate is an
effective means for reducing the discomfort and pain
engendered by thermal and tactile stimuli.

41. PotassiumNitrate
 Greenhill and Pashleyfound potassium nitrate - ineffective in decreasing any
dentinal fluid flow in in vitro coated dentin, even at a 30% concentration.
 But many investigators have found 5% potassium nitrate an excellent dentinal
desensitizing agent.
 Hodash (1974) called potassium nitrate a superior desensitizer and found it to be
highly effective at concentrations of 1 to 15 %
 In a controlled study, Tarbet et al found 5% potassium nitrate-paste able to
desensitize the dentin effectively at 1 week and up to 4 weeks compared to the
control (paste without potassium nitrate) in 92% of the subjects. In a follow-up
report, which histologically examined the pulpal effects of the previous study, it
was determined that "potassium nitrate did not induce any pulpal tissue change

42. Sodium monoflurophospate
 In a study by Arowojolu (2001) , the desensitizing effect of sodium
monoflurophosphate was better than srontium chloride.
 In conclusion a commercially available dentrifice of Na
monoflurophospahte as its active ingredient - effective results
after 6 weeks.

43. A. Varnish/Precipitants
 5% sodium fluoride in a thick varnish – by Clark et al (1985).
 HEMA containing primers like GULMA [5% gluteraldehyde and
35% HEMA]

44. Corticosteroids
 Anti-inflammatory effect of glucocorticoids …. decrease dentinal sensitivity
 Mjor and Furseth ….. application of corticosteroid preparation to dentin
caused complete obliteration of tubules .
 Mosteller …. liner consisting of 1% prednisolone in combination with 25%
parachlorophenol, 25% m-cresyl acetate and 50% gum camphor prevented
postoperative thermal sensitivity
 Mjor showed that steroid application to dentin increased peritubular dentin
mineralization.
 Thus, the tubule lumen would be decreased, resulting in less dentin tubule
fluid movement, reducing the dentinal sensitivity.
 Green et al compared steroid application to Ca(OH)2 in their ability to
induce mineralization. The results were very similar for both compounds,
with the steroid causing "completely obturated tubules" and calcification
"in an area of the dentine where no highly mineralized peritubular matrix is
normally found."

45. Burnishing of dentin
 Tooth pick or "orange wood stick … creates a partial smear layer on dentin
surface .
 Reduced fluid movement by 50% to 80% .
 More effective in reducing dentin permeability than burnishing with glycerin
alone or glycerin in combination with sodium flouride.
 Pashley et al - The effects on dentin permeability of burnishing NaF, kaolin, or
glycerin, alone and in various combinations, were determined using an in vitro
system. The results indicate that the important variable was not any of the
constituents of the paste but the burnishing process itself.

46. Silver nitrate
 Powerful protein precipitant .
 Greenhill and Pashley found that the silver nitrate either alone or in
combination with formalin ppted silver chloride or elemental silver
 It may cause pulpal inflammation in shallow cavities.
 Naylor and Anderson and Matthews measured dentin sensitivity
before and after silver nitrate application and found no significant
difference in pain response.
 Thus, silver nitrate may be ineffective and is possibly deleterious in
the management of dentin sensitivity.

47. Calciumhydroxide
 It may block dentinal tubules or promote peritubular dentin formation .
 Brannstrom (1976) … construction of the dentinal tubules… depth of 0.1mm .
 Mjor (1967)…micro radiography… increased radio density
 In a study by Greene et al hydroxide was an effective desensitizing agent over the control to
mechanical, hot and cold stimulation .Calcium hydroxide out-performed potassium nitrate
at all time intervals throughout cold stimulation and therefore is especially recommended
as a desensitizing agent for those patients who are sensitive only to cold.
 Jorkjend and Tronstad applied calcium hydroxide to sensitive teeth following periodontal
surgery, sealing it in with polymethacrylate and a periodontal pack. They found best results
were obtained after 7 days, with the teeth no longer sensitive to cold, air, carbohydrates,
toothbrushing, toothpicks, scaling or ultrasonic devices
 In a 3-month clinical study, Green et al found calcium hydroxide applications consistently
effective in relieving cervical hypersensitivity

48. Hydroxyapatite
 Shetty et al evaluated Hydroxyapatite as an In-Office Agent for
Tooth Hypersensitivity - showed definite potential as an effective
desensitizing agent providing quick relief from symptoms. None
of the patients reported any adverse responses to the agent

49. Fluoride
 Mechanism of action….
 increasing the amount of reparative dentin, or
 by precipitating calcium fluoride in the tubules
 Johnson et al (1981) stannous fluoride with the ionizing brauh provided
significantly greater relief than did the stannous fluoride alone.
 Clement and Hoyt and Bibby (using 33.3% NaF) found sodium fluoride very
effective in reducing dentinal hypersensitivity in subjective, noncontrolled studies.
However, sodium fluoride may produce severe pulpal inflammation when applied
to dentin.

50. Fluoride Iontophoresis
 A low voltage electric current is used to impregnate the tooth with fluoride ions.
 Two to six times more fluoride can be impregnated into dentine than when
treated with topical sodium fluoride.
 Manning described an iontophoretic device which would work
electrophoretically to desensitize dentin.
 Using 2% NaF with iontophoresis, Carlo (in a noncontrolled study) found
"significant relief from sensitivity“ in 90% of cases.
 Singal et al - 2% NaF was comparatively better than HEMA-G in providing long-
term relief

51. Intra oral fluoride releasing device.
 Sodium fuoride in an acrylic polymer releasing fluoride at the rate
of 0.04mg/day,
 This device is fast , painless and cost effective (marini et al 2010)

52.  Orsini et al (2013) compared -
 Three dentifrices [1) containing 8% arginine, 1450ppm sodium
monofluorophosphate; 2) containing 8% strontium acetate,
1040ppm sodium fluoride; 3) containing 30% micro-aggregation
of zinc-carbonate hydroxyapatite nanocrystals] were compared
after 3-day treatment .
 This study documented that the three tested dentifrices
significantly reduced DH after 3-day treatment, supporting their
utility in clinical practice. This is the first report documenting the
rapid relief from DH of a zinc-carbonate hydroxyapatite
dentifrice.

53. Oxalates
 used popularly as desensitizing agent
 inexpensive
 easy to apply and
 well tolerated by the patients
 Potassium oxalate and ferric oxalate solutions -calcium ions in the
dentinal fluid to form insoluble calcium oxalate crystals.
 Muzzin et al compared 30% dipotassium Oxalate (DO) and 3%
monohydrogen-monopotassium Oxalate (MO) on the reduction of dentin
hypersensitivity in vivo. Results suggested - decrease in dentin
hypersensitivity following the application of 3% MO alone, and 30% DO
followed by 3% MO.

54. Lasers
 Studies have reported that the neodymium:YAG laser, the erbium:YAG
laser and galium-aluminium-arsenide, erbium, chromium-
doped:yttrium, scandium, gallium, and garnet all reduce DH
 A more expensive and complex treatment modality.
 Kumar et al - The combination of Nd:YAG laser and 5% sodium
fluoride varnish seems to show an impressive efficacy, when compared
to either treatment alone, in treating dentin hypersensitivity.
 Yilmaz et al (2011) evaluate the efficacy of er cr ysgg laser on reduction
in dh. Immediately after treatment the er cr ysgg laser had a
significant higher desensitizing effect and the results were stable after
3 months

55. Dentine bonding agents
 Bonding agents are applied to the exposed dentine
 Easy to apply
 Aesthetically acceptable
 Brannstrom et al. obtained "immediate and lasting blockage of
sensitivity" in 20 patients studied from 2 to 12 months. This is in
agreement with Dayton et al. who tested various unfilled resins in 44
teeth.
 Narhi et al. recorded nerve activity directly in cat teeth when dentin
was mechanically stimulated. He found no neural activity after resin
impregnation.

56. Composite/ glass ionomer restorations
 Long lasting, yet more invasive procedure
 Is indicated when there is significant loss of tooth structure

57. GC toothmousse
 Kowalczyk A et al
 GC Tooth Mousse for dentine hypersensitivity was evaluated -
cold air stream
 Min. 6 weeks of topical application would reduce hypersensitivity.
CPP-ACP: Casein Phosphopeptide –
Amorphous Calcium Phosphate).

58. Nano structuresbioactive glass.
 -Mitchell et al(2011)
 Nano structured sol gel bioactive glass with carrier fluid showed a
significant change in reduction of conductance…
 Produced an immediate reduction in
fluid conductance, and maintaining it for at least 7 days

59. Conclusion.
 Much has been learnt about hypersensitivity since it has been
described as an enigma 20 years ago.
 The ultimate goal in the treatment of dentine hypersensitivity is
the immediate and permanent relief of pain
 Professionals should identify the causative factors so that
prevention can also be included in the treatment plan

60. References.
 Calcium Hydroxide and Potassium Nitrate as Desensitizing Agents for
Hypersensitive Root Surfaces, GREEN et al , jop J. Periodontol. October, 1977.
 Clinical Evaluation of a New Treatment for Dentinal Hypersensitivity, Tarbet et al ,
J. Periodontol. September. 1980
 The Effectiveness of an Electro-Ionizing Toothbrush in the Control of Dentinal
Hypersensitivity, Johnson et al, J. Periodontol: June, 1982.
 Dentinal Sensation and Hypersensitivity A Review of Mechanisms and Treatment
Alternatives, Berman, Volume 56, Number 4, i. Periodontol. April, 1984.
 The Effects of Burnishing NaF/Kaolin/Glycerin Paste on Dentin Permeability,
Pashley et al, J Periodontol. January, 1987. Volume 58 Number 1
 Efficacy of Strontium Chloride in Dental Hypersensitivity, Minkof et sl , J.
Periodontol. July, 1987 Volume 58 Number 7.
 Effects of Potassium Oxalate on Dentin Hypersensitivity in Vivo, Muzzin et al, J.
Periodontol. March 1989, Volume 60 Number 3.
 Intraora fluoride releasing device: a new clinical therapy for dentin sensitivity,
merini et al , JOP 2000 vol 71, 90-95.

61.  2% Sodium Fluoride-Iontophoresis Compared to a Commercially Available
Desensitizing Agent. Singal et al , J Periodontol 2005;76:351-357.
 Short-Term Assessment of the Nd:YAG Laser With and Without Sodium
Fluoride Varnish in the Treatment of Dentin Hypersensitivity – A Clinical
and Scanning Electron Microscopy Study, Kumar et al , J Periodontol
2005;76:1140-1147.
 Hydroxyapatite as an In-Office Agent for Tooth Hypersensitivity: A Clinical
and Scanning Electron Microscopic Study, shetty et al, J Periodontol
2010;81:1781-1789.
 A 3-Day Randomized Clinical Trial to Investigate the Desensitizing
Properties of Three Dentifrices, Orsini et al, Journal of Periodontology;
2013 , DOI: 10.1902/jop.2013.120697 .
 BIOMIMETIC DENTIN DESENSITIZER BASED ON NANO-STRUCTURED BIOACTIVE
GLASS, Mitchell et al J Dental materials 2011;27:386–393.
 Yilmaz HG, Cengiz E, Kurtulmus-Yilmaz S, Leblebicioglu B. Effectiveness
of Er,Cr:YSGG laser on dentine hypersensitivity: a controlled clinical trial. J
Clin Periodontol. 2011 Apr;38(4):341-6.

62. Thank you