INDIAN DENTAL ACADEMY    Leader in Continuing Dental Education        www.indiandentalacademy.comwww.indiandentalacademy.com
CONTENTSIntroductionDefinitionAnatomy & histology of dentineMechanism of stimulus transmissionClinical featuresPrevelanceD...
INTRODUCTIONOne of most important and main objective of dentist has been thecontrol or elimination of pain. Painful sympto...
•Definition:Dentinal hypersensitivity may be defined as short sharp painarising from exposed dentin, typically in response...
Anatomy and histology of dentin:Dentine is the hard tissue portion of the pulp dentin complex andforms the bulk on the too...
material mainly ofhydroxyapatite,20% organic material - type Icollagen with glycoproteins,proteoglycans,phosphoproteins an...
Contents of tubule:Odontoblast and its process, nerves are also found in some tubules.Fluid that is assumed to be present ...
DENTINE: Composition    MATRIX subdivided into      Peritubular dentine                                Inter-tubular denti...
Types:Predentin:Its a layer of variable thickness 10 - 47 mm that lines the inner mostportion of the dentin. It is unminer...
Enamel                     PREDENTINE                                           DENTINEOdontoblasts          Direction of ...
MATURE DENTINE: Varieties                     MANTLE DENTINE just below                     DEJ coarser fibrils           ...
Dentine permeability:It is constant interchange of fluid between dentine & pulp. It differs from one person toanother and ...
NEUROANATOMY OF PULP AND DENTINE:Nerve fibers entering the teeth have been identified histologically asmyelinated A - fibe...
Trow bridge summarized 4 types of nerve endings where they terminated1. Marginal fibers: simple pulp fibers extending from...
By tooth eruption, both myelinated and unmyelinated nervesreach the odontogenic regions and lie close to the odontoblast.A...
www.indiandentalacademy.com
MECHANISM OF STIMULUS TRANSMISSION ACROSSDENTINPashley & Parson suggested mechanism of dentinalhypersensitivity to be clas...
Theory ]:This theory of dentinal sensation takes into consideration the "synaptic-like" relationship between the terminal,...
www.indiandentalacademy.com
Gate Control Theory:When the dentin is irritated, for example, by cavity preparation, all of thepulpal nerves become activ...
Hydrodynamic Theory:Fish in 1927 observed the interstitial fluid of the dentin andpulp, referring to it as the "dental lym...
According to the hydrodynamic theory, as put forth by Brannstrom andAstrom, a dentinalgia results from a stimulus causing ...
www.indiandentalacademy.com
It is also a common clinical finding that pain is produced whensugar or salted solutions are placed in contact with expose...
www.indiandentalacademy.com
www.indiandentalacademy.com
ColdHot       www.indiandentalacademy.com
Clinical features:•It’s a symptom complex rather than true disease•The teeth diagonosed as exhibiting dentine sensitivity ...
Prevelance:The prevelance of DH varies from 45-57%. Cause for variation is attributedto differences in the population stud...
Distribution•It mostly occurs in patients who are between 30 & 40 yrs old, it mayeffect patients of any age•It affects wom...
ETIOLOGY :Essentially exposure of the dentin may result from one of theprocesses:  either removal of the enamel covering t...
Denudation of the root surface is multifactorial with     acute & chronic periodontal disease     following non-surgical p...
www.indiandentalacademy.com
www.indiandentalacademy.com
METHODS USED TO MEASURE /TEST HYPERSENSITIVITY :       Tactile        Thermal        Osmotic        ElectricalTactile meth...
A device with a 15 mm (0.26 gauge) stainless steel wire with a tip ground toa fine point & movable across the highest arc ...
www.indiandentalacademy.com
Hand held scratch device by Kleinberg:Another tactile method is a hand held scratch device developed byKleinberg (1990) wh...
Thermal:A simple thermal method for testing is directing a burst of air atroom temperature from a dental syringe on to the...
contact metal probes have been used in a number ofHypersensitivity studies.The tip diameter of these probes is usually sma...
www.indiandentalacademy.com
Osmotic :This method is based on the principle of osmosis i.e. movement offluid from higher concentration to lower concent...
Electrical :Electrical measurements differ from the others as in this a pain responsecan be obtained from non-sensitive as...
www.indiandentalacademy.com
www.indiandentalacademy.com
MANAGEMENT OF DENTINAL HYPERSENSITIYITY:History :Opium therapy, the earliest recorded treatment method, dates to400 BC and...
www.indiandentalacademy.com
In 1935, Grossman suggested the criteria for the idealdesensitizing agent.Desensitizing agents should be    nonirritating ...
Dental conditions with symptoms similar to dentine hypersensitivity :Cracked tooth syndromeFractured restorationsChipped t...
www.indiandentalacademy.com
www.indiandentalacademy.com
Office treatments for dentinal hypersensitivity :Cavity varnishes                                     Stannous fluorideAnt...
Desensitizing agents:Pattisson and Pattison listed the following possible mechanism of action fordesensitizing agents.Prec...
There are variety of physiochemical mechanisms that can lead to suchreduction in permeability and sensitivity of dentin.  ...
The concept of tubule occlusion as a method of dentindesensitization is logical extension of Hydrodynamic theory.But not a...
Fluorides:Sodium fluoride:Clinical investigations have shown fluoride tooth paste andconcentration of fluoride solutions a...
It has been demonstrated that aqueous solutions of stannousfluoride in low concentration will effectively control Dentinhy...
Strontium :A possible explanation for the mechanism of action of strontium ion insuppressing Dentin Hypersensitivity had b...
Calcium hydroxide :Calcium hydroxide has been a popular agent for the treatment of dentinhypersensitivity for many years p...
The use of a dentifrice containing formalin was reported by Fitzgerald(1956) who noted excellent results in most of patien...
Oxalates :Oxalates have been used popularly as desensitizing agent, they arerelatively inexpensive, easy to apply and well...
Iontophoresis is a method of facilitating the transfer of ions by means of anelectrical potential into soft or hard tissue...
Lasers :Types used : Argon, Co2, Ho:YAG, Nd:YAG, erbium YAG etc. These systemshave become available which are tailored spe...
Burnishing of dentin :Burnishing of dentin with tooth pick or orange wood stick willcreate a partial smear layer on dentin...
www.indiandentalacademy.com
SUMMARY AND CONCLUSIONDentin hypersensitivity is a problem that plagues many patients.The initial or continued clinical ca...
REFERENCESwww.indiandentalacademy.com
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Dentinal hypersensitivity /certified fixed orthodontic courses by Indian dental academy

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Dentinal hypersensitivity /certified fixed orthodontic courses by Indian dental academy

  1. 1. INDIAN DENTAL ACADEMY Leader in Continuing Dental Education www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. CONTENTSIntroductionDefinitionAnatomy & histology of dentineMechanism of stimulus transmissionClinical featuresPrevelanceDistributionEtiologyMethods of measurementManagement protocols www.indiandentalacademy.com
  3. 3. INTRODUCTIONOne of most important and main objective of dentist has been thecontrol or elimination of pain. Painful symptoms arising fromexposed dentine are a common finding in Adult population &have been reported to effect as many as 1 in 7 of patientsattending the dental operatory. (Graf & Galasse, 1977)Although many individuals seem to have exposed dentine but notall experience symptoms. There is no clear cut explanation for thisbut certain factors may be implicated age, rate of exposure of www.indiandentalacademy.com
  4. 4. •Definition:Dentinal hypersensitivity may be defined as short sharp painarising from exposed dentin, typically in response to stimuli-typically thermal, chemical, tactile or osmotic that cannot beascribed to any other dental defect or pathology (disease).[Canadian Advisory Board on Dentinal Hypersensitivity; 2003]The terms dentinal, dentin, or tooth sensitivity frequently havebeen used.The condition has also been referred to as cervical dentinhypersensitivity and as cervical tooth sensitivity , adding alocation based descriptor to differentiate it from other types oftooth pain. www.indiandentalacademy.com
  5. 5. Anatomy and histology of dentin:Dentine is the hard tissue portion of the pulp dentin complex andforms the bulk on the tooth. ENAMEL GINGIVA DENTINE PULP CEMENTUM PERIODONTAL ALVEOLAR BONE LIGAMENT/ PDL www.indiandentalacademy.com
  6. 6. material mainly ofhydroxyapatite,20% organic material - type Icollagen with glycoproteins,proteoglycans,phosphoproteins and plasma MATRIX of type – I collagen fibrilsproteins and 10% water. glycoproteins, proteoglycansIt is Characterized by closelypacked dentinal tubules that Mineral crystals - Hydroxyapatitesurround its entire thicknessand contain the cytoplasmicextensions of odontoblasts,cells that once formed thedentin and now maintain it.The cell bodies ofodontoblasts are aligned along ODONTOBLASTS & their processesthe aspect of the dentine, www.indiandentalacademy.comwhere they also form the
  7. 7. Contents of tubule:Odontoblast and its process, nerves are also found in some tubules.Fluid that is assumed to be present which might be equivalent to serum.It is thought that apart from collagen and nerve fibrils, the fluid mightcontain proteoglycans, tenascin, the serum protein albumin, transferrinand type V collagen. www.indiandentalacademy.com
  8. 8. DENTINE: Composition MATRIX subdivided into Peritubular dentine Inter-tubular dentineTUBULES 1-3 µm wide www.indiandentalacademy.com
  9. 9. Types:Predentin:Its a layer of variable thickness 10 - 47 mm that lines the inner mostportion of the dentin. It is unmineralized and consists principally ofcollagen, glycoproteins and proteoglycans.Primary dentin:Most of the tooth is formed by primary dentin, which outlines the pulpchamber. The outer layer of primary dentin is called mantle dentin.This is the l st layer formed by newly differentiated odontoblasts. The organicmatrix lacks phosphate and loosely packed coarse collagen fibrils.Secondary dentin:It develops after root formation. It was thought that secondary dentin isformed only in response to stimuli but it has been found in unerupted teethas well. www.indiandentalacademy.comThus secondary dentin represents the continuing but much slower
  10. 10. Enamel PREDENTINE DENTINEOdontoblasts Direction of growth - pulpward from DEJ www.indiandentalacademy.com
  11. 11. MATURE DENTINE: Varieties MANTLE DENTINE just below DEJ coarser fibrils PRIMARY (CIRCUMPULPAL) DENTINE - main mass of dentine {PU TERTIARY DENTINE - slowL increment to pulpal surfaceP REPARATIVE DENTINE - response to caries/erosion www.indiandentalacademy.com
  12. 12. Dentine permeability:It is constant interchange of fluid between dentine & pulp. It differs from one person toanother and from one area to other.FACTORS GOVERNING DENTINAL PERMEABILITY:•Types of dentine•Type & nature of diffusants•Degree of mineralization•Dentine exposed during g tooth preparation•Effective depth•Induced stresses•Hydraulic pressure•Deficient resistance and retention form•Micro leakage•Cracks & micro cracks in dentine & enamel•Types of intermediary base or restorative material www.indiandentalacademy.com
  13. 13. NEUROANATOMY OF PULP AND DENTINE:Nerve fibers entering the teeth have been identified histologically asmyelinated A - fibers and unmyelinated C-fibers. Both A and C and provideboth fast and slow conduction.They are grouped in bundles and enter through the apical foramina of theteeth and pass through the radicular to the coronal pulp where they fan outand diverge into smaller bundles.Nerve divergence continues, individual A-fibers within small bundles losetheir myelin sheath and divide repeatedly before finally ramifying into aplexus of single axons known as the subodontoblastic plexus or plexus ofRashkow.From this plexus, nerve fibers are distributed toward the pulp dentin border www.indiandentalacademy.com
  14. 14. Trow bridge summarized 4 types of nerve endings where they terminated1. Marginal fibers: simple pulp fibers extending from sub odontoblastic nerve layer; don’t reach predentine.2. Simple predentinal fibers: extend upto odontoblast predentine border or enter predentine.3. Complex predentinal fibers: reach predentine; undergo terminal ramification with multiple branching and multiple ending like branching on each branch4. Dentinal fibers: these pass through predentine with branching and enter dentin through dentinal tubule www.indiandentalacademy.com
  15. 15. By tooth eruption, both myelinated and unmyelinated nervesreach the odontogenic regions and lie close to the odontoblast.According to Narhi and co-workers, it would appear that A-fibers account for the sensitivity of dentin (dentinal pain).Most are Aδ fibers, where as C fibers respond when externalirritants (i.e. chemical agents) reach the pulp (pulpitis). www.indiandentalacademy.com
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  17. 17. MECHANISM OF STIMULUS TRANSMISSION ACROSSDENTINPashley & Parson suggested mechanism of dentinalhypersensitivity to be classified according to three hypothesis:1. nerve endings/ nociceptors respond directly when dentine isstimulated(threoughout the dentin)2. odontoblasts being chemically or electrically related to nerves3. stimuli applied to dentine- produce displacement of dentinaltubule content- excite mechanosensitive nerve endings nearpulpal end of tubules [hydrodynamic mechanism] www.indiandentalacademy.com
  18. 18. Theory ]:This theory of dentinal sensation takes into consideration the "synaptic-like" relationship between the terminal, sensory nerve endings and theodontoblastic processes. If a true synapse were present between these twoelements to facilitate the transmission of dentinal sensations, then a neuraltransmitting substance such as acetylcholine would be expected in this areaof the odontoblastic process and the predentin. There is no direct evidencefor the presence of acetylcholine activity in the neural transmission in thepulp.Modulation Theory:Upon an irritating stimulus to the dentin, the odontoblasts may becomeinjured and subsequently release a variety of neurotransmitting agents aswell as vasoactive and pain producing amines and proteins. These www.indiandentalacademy.comsubstances may modulate associated nerve fiber action potentials by
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  20. 20. Gate Control Theory:When the dentin is irritated, for example, by cavity preparation, all of thepulpal nerves become activated from the vibrations.The larger myelinated fibers may accommodate to the sensations. The smallerC-fibers may tend to be maintained and not adjust to the stimulus.Thus, as the low-intensity "pain gates" from the larger fibers are closed, thehigh-intensity "pain gates" from the smaller fibers are enhanced.However, the gate theory does little to explain how pain responses from thedentin are transmitted and perceived by the nerve endings of the pulp andhow they may be centrally interpreted. www.indiandentalacademy.com
  21. 21. Hydrodynamic Theory:Fish in 1927 observed the interstitial fluid of the dentin andpulp, referring to it as the "dental lymph."He postulated that the flow of this fluid could take place ineither an outward or inward direction depending on the pressurevariations in the surrounding tissue.This idea of fluid movement within the dentinal tubules is thebasis for the transmission of sensations according to thehydrodynamic theory. www.indiandentalacademy.com
  22. 22. According to the hydrodynamic theory, as put forth by Brannstrom andAstrom, a dentinalgia results from a stimulus causing minute changes in thefluid movement within the dentinal tubules.This may subsequently deform the odontoblast or its process and hence causean elicitation of pain via the intimately associated "mechano-receptor-like"nerve endings.i.e this increased flow, in turn, causes a pressure change across the dentine,which activates A- delta intradental nerves at the pulp-dentine border orwithin the dentinal tubules. www.indiandentalacademy.com
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  24. 24. It is also a common clinical finding that pain is produced whensugar or salted solutions are placed in contact with exposeddentin.When the irritant is rinsed or brushed away, the discomfortsubsides.This again can be explained by dentin tubule fluid movements.Fluids of a relatively low osmolarity (i.e., dentinal tubule fluid)will have a tendency to flow towards solutions of higherosmolarity (i.e., salt or sugar solutions).When isoosmotic solutions are applied, no stimulus is felt. www.indiandentalacademy.com
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  27. 27. ColdHot www.indiandentalacademy.com
  28. 28. Clinical features:•It’s a symptom complex rather than true disease•The teeth diagonosed as exhibiting dentine sensitivity when extracted andstudied under by SEM, exhibited in excess of seven times the mean surfacestubule count at buccal cervical dentinal sitescompared with teeth classifiedas non sensitive•Tubules at hypersensitive sites had a mean diameter twice that at a nonsensitive sites.•Dentinal hypersensitivity is uisually dioagonosed after other possibleconditions havbe been eliminated like chipped or fractured teeth, fracturtedrestorations, caries etc. www.indiandentalacademy.com
  29. 29. Prevelance:The prevelance of DH varies from 45-57%. Cause for variation is attributedto differences in the population studied and methods of investigation 9foreg questionaires & clinical examinationsPrevelance of DH is between 60-98% in patients with periodontitis.[Chabanski MB et al . Prevelance of cervical dentine sensitivity in apopulation of patients reffered to a specialist periodontology department:JCP 1996; 23: 982-92]Schuurs & colleagues reported that dentists believe DH represents a severeproblem for only 1% of their diagnosed patients. www.indiandentalacademy.com
  30. 30. Distribution•It mostly occurs in patients who are between 30 & 40 yrs old, it mayeffect patients of any age•It affects women more often than men though sex difference rarely isstatically significant•The condition may effect any tooth but it most often affects canines &premolars; buccal cervical zones of permanent teeth.•In right handed patients, dentinal hypersensitivity is obseved on left sideof mouth of patients. www.indiandentalacademy.com
  31. 31. ETIOLOGY :Essentially exposure of the dentin may result from one of theprocesses: either removal of the enamel covering the crown or denudation of the root surface by loss of cementum andoverlying periodontal tissues.Removal of the enamel may result from : attrition occlusal abnormalities tooth brush abrasion dietary erosion www.indiandentalacademy.com habit/ parafunction
  32. 32. Denudation of the root surface is multifactorial with acute & chronic periodontal disease following non-surgical periodontal therapy incorrect tooth brushing chronic trauma from habits gingival recession increasing with advancing ageFactors such as method and frequency of brushing, the brushtype, the dentifrice used all relate to the effects produced on softand hard tissues.Erosive agents primarily acids, environmental, dietary orendogenous are known to cause the damage.Occupational:Workers exposed to fumes of HC1, sulfuric, nitric, www.indiandentalacademy.com
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  35. 35. METHODS USED TO MEASURE /TEST HYPERSENSITIVITY : Tactile Thermal Osmotic ElectricalTactile method :A.The simplest tactile method used to test for hypersensitivity isto lightly pass a sharp explorer over the sensitive area of tooth(usually along the CEJ).Patient response is graded on a scale. 0 - No pain felt 1 - Slight pain or discomfort 2 - Severe pain www.indiandentalacademy.com
  36. 36. A device with a 15 mm (0.26 gauge) stainless steel wire with a tip ground toa fine point & movable across the highest arc curve of facial surface of thesensitive tooth under test.Pressur in wire is increased with adjustment screw incrementally in ¼ or1/3 of mm until subject is able to feel a pain sensation. At that point , thescratching force expressed in mm is taken as threshold value. If no pain isfelt tooth is considered as Non sensitive.C. force sensitive electronic probe by Yeapleused for measurement of periodontal pocket at fixed pressure. In dentinalhypersensitivity test, probe force can be increased in steps of 5 gms untilthe subject experience discomfort, that point is taken as pain threshold. www.indiandentalacademy.com
  37. 37. www.indiandentalacademy.com
  38. 38. Hand held scratch device by Kleinberg:Another tactile method is a hand held scratch device developed byKleinberg (1990) which consists of torsion gauge and a sharpexplorer like probe that can be passed easily across a sensitivetooth.It has an indicator that is displaced by the arm of the explorerthat records the force of displacement in centi-newtons .A tooth that fails to respond to a force of 80 centi-newtons isclassified as non sensitive. www.indiandentalacademy.com
  39. 39. Thermal:A simple thermal method for testing is directing a burst of air atroom temperature from a dental syringe on to the test tooth.Room air is cooler than teeth and cooling by this means is easilydetected as pain if tooth is sensitive.Air stimulation has been standardized in number of studies as aone second blast from the air syringe of a dental unit, where itstemperature is set generally between 65° and 70° F and apressure 60 psi. (the air is directed at right angles to test surfacewith adjacent teeth usually isolated by operators fingers). 0 - No discomfort 1 - Discomfort but no severe pain 2 - Severe pain-during application www.indiandentalacademy.com
  40. 40. contact metal probes have been used in a number ofHypersensitivity studies.The tip diameter of these probes is usually small enough to permitplacement in the cervical area of a tooth.One such device developed by Smith and Ash, the temperature ofthe probe tip was measured with a thermistor embedded in thetip.A flow of current in one direction was used to cool the probe tipfrom room temperature to 12°C, current flow in the otherdirection heated the tip to 82°C.Intensity of the current to the probe from a power supplycontrolled the temperature. The initial temperature (standard)37.5°CFor cold stimulation 1°C is reduced and the tip is placed incontact with tooth, for heat stimulation it is increased in 1°C www.indiandentalacademy.comincrements and placed in contact with tooth. Temperature at
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  42. 42. Osmotic :This method is based on the principle of osmosis i.e. movement offluid from higher concentration to lower concentration.An osmotic method consisting of the subjective pain response to asweet stimulus was used by Mcfall and Hamrick in 1987 tomeasure the effect of several test dentifrices on dentinalsensitivity.This was done by preparing fresh saturated solution of sucroseallowing it to reach room temperature.After isolation of the test tooth with cotton rolls, a cottonapplicator was saturated with sucrose solution and then appliedto the root surface of the tooth and allowed to remain in place for www.indiandentalacademy.com
  43. 43. Electrical :Electrical measurements differ from the others as in this a pain responsecan be obtained from non-sensitive as well as from sensitive teeth.Instruments for application of electrical stimulus of increasing intensity,e.g: pulp testers, were used mainly to determine the vitality.Instrument improvements led to better quantification of the electricalstimulus and discovery, that a condition of "pre-pain" consisting of atingling or warm sensation is observed before real pain and discomfort arefelt by the patient as the magnitude of stimulus is increased.For stimulating a tooth electrically, the basic constituents are anelectrode or probe to apply the electrical stimulus so that its magnitudecan be progressively increased and a means of completing the electrical www.indiandentalacademy.comcircuit, electrolyte (eg. tooth paste) required.
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  46. 46. MANAGEMENT OF DENTINAL HYPERSENSITIYITY:History :Opium therapy, the earliest recorded treatment method, dates to400 BC and was still advocated as late as 1000 AD.A wide variety of treatments such as henbane plant and crushedbeetles were recommended until the late 1800s.Cocaine was introduced in 1859 and other medicaments such ascreosate and tannic acid and arsenic were used at the turn of thecentury. In the 1920s, aqueous solutions of iodine with silver iodide werereported to be effective for relieving dentinal sensitivity and didnot blacken the tooth surface as did silver nitrate. www.indiandentalacademy.com
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  48. 48. In 1935, Grossman suggested the criteria for the idealdesensitizing agent.Desensitizing agents should be nonirritating to the pulp, relatively pain less on application, easily applied, rapid in action permanently effective, consistently effective and cause no staining.Hot olive oil, formaldehyde, silver nitrate, zinc chloride, sodiumcarbonate, and sodium fluoride were used in the 1950s, many ofthese materials are used to stimulate the formation of secondarydentin, and some are adhesive and used for covering the sensitive www.indiandentalacademy.comareas.
  49. 49. Dental conditions with symptoms similar to dentine hypersensitivity :Cracked tooth syndromeFractured restorationsChipped teethDental cariesPost-restorative sensitivityTeeth in acute hyperfunction www.indiandentalacademy.com
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  52. 52. Office treatments for dentinal hypersensitivity :Cavity varnishes Stannous fluorideAnti-inflammatory agents IonotophoresisBurnishing of dentin Strontium chlorideSilver nitrate Potassium oxalateZinc chloride - potassium ferrocyanideFormalin Restorative resinsCalcium compounds Dentin bonding agentsCalcium hydroxideDiabasic calcium phosphateFluoride compoundsSodium fluorides www.indiandentalacademy.com
  53. 53. Desensitizing agents:Pattisson and Pattison listed the following possible mechanism of action fordesensitizing agents.Precipitating or denaturing organic material at the exposed end of the(odontoblastic process) tubule.Depositing an inorganic salt at the supposed end of the dentinal tubulesStimulating secondary dentin formation with in the pulp.Suppressing pulpal inflammationMyjor suggests that the treatment should be aimed towards a reduction inthe permeability of the dentin rather than towards an attempt to stimulatesecondary dentin .Treatment through tubules occlusion:Several therapeutic approaches to tubule occlusion have been developed withpromise as dentin desensitizing agents. www.indiandentalacademy.com
  54. 54. There are variety of physiochemical mechanisms that can lead to suchreduction in permeability and sensitivity of dentin. Formation of calculus over sensitive tubules. Formation of intra tubular crystals from salivary mineral Intratubular crystals from dentinal fluid Progressive formation of peritubular dentin Invasion of tubules by bacteria Formation of caries crystals Formation of intratubular collagen plugs Leakage of plasma proteins up into tubules Formation of smear layer by brushing, tooth pick etc. Formation of irritation dentin Resin impregnation or covering www.indiandentalacademy.com Topical application of calcium hydroxide, sodium fluoride .
  55. 55. The concept of tubule occlusion as a method of dentindesensitization is logical extension of Hydrodynamic theory.But not all agents that decrease dentin sensitivity do so byoccluding dentinal tubules.This is because there are 2 mechanisms of action of desensitizingagents.One involves blocking fluid movements by occluding dentaltubules.The other involves blocking pulpal nerve activity by altering theexcitability of sensory nerves. www.indiandentalacademy.com
  56. 56. Fluorides:Sodium fluoride:Clinical investigations have shown fluoride tooth paste andconcentration of fluoride solutions are highly efficientespecially with iontophoric technique.Fluoride was first proposed as a desensitizing agent byLukomsky in 1941.The use 2% sodium fluoride following pretreatment with, 10%strontium chloride was observed to have an additive effect inreducing sensitivity ( Gedalia et al 1978) although sodiumfluoride alone was still significantly effective. www.indiandentalacademy.com
  57. 57. It has been demonstrated that aqueous solutions of stannousfluoride in low concentration will effectively control Dentinhypersensitivity (Miller et al 1949).Two concepts have been put forward for the mechanism of actionof stannous fluoride.That it acts as an enzyme to inactivate the odonotoblasticprocess. (Kutsches 1967).That it induces high mineral content which creates a calcificbarrier on the dentin surface ( Furseth 1970).In view of the questionable importance of the odontoblast processin pain transmission the former suggested mode of action appearsunlikely.As with sodium fluoride the formation of a calcific barrier www.indiandentalacademy.com
  58. 58. Strontium :A possible explanation for the mechanism of action of strontium ion insuppressing Dentin Hypersensitivity had been advanced by Gutentag.He proposed that because calcium has been shown to establish excitableneural membranes by modifying their permeability to Na + and K + the effectwas more pronounced and long lasting with strontium.As a result effects in Dentin Hypersensitivity were attributed to a blockageof the organic matrix of the tooth ( Powlowska 1956) . www.indiandentalacademy.com
  59. 59. Calcium hydroxide :Calcium hydroxide has been a popular agent for the treatment of dentinhypersensitivity for many years particularly after root planing.The exact mechanism of action is unknown, but evidence suggests that itmay block dentinal tubules or promote peritubular dentin formation.Increasing the concentration of calcium ions around nerve fibers can resultin decreased nerve excitability and thus suppresses nerve activity.Potassium nitrate :The desensitizing effectiveness of potassium nitrate used in professionalhands has been reported by Hodosh in 1974 and Green et al 1977.Tarbet et al (1980) demonstrated for the first time that the daily use of 5%potassium nitrate delivered in low abrasive toothpaste constituted a highlyeffective home therapy regime for patients with Dentin hypersensitivity.Penetration of K + ions into pulp, there by sensory nerves are prevented to www.indiandentalacademy.comrepolarise after depolarization.
  60. 60. The use of a dentifrice containing formalin was reported by Fitzgerald(1956) who noted excellent results in most of patients seeking relief fromcervical hypersensitivity.However, Smith and Ash 1964 using as more objective method of evaluatingresponses to thermal and mechanical stimuli, found no significant alterationof Hypersensitivity after use of dentifrices containing formalin.Resin and adhesives :The rationale for the use being the possibility of sealing dentinal tubules.Results of studies were promising and have demonstrated an immediate andlong lasting blockage of sensitivity on most surfaces for between 1 monthand 1 year.Doereig and Jensen (1985) have used light cure dentin bonding agents out of12 participants withwww.indiandentalacademy.com hypersensitivity, 74% reported no pain three months
  61. 61. Oxalates :Oxalates have been used popularly as desensitizing agent, they arerelatively inexpensive, easy to apply and well tolerated by the patients.6% Ferric oxalate 30% potassium oxalate and 3% Monohydrogenmonopotassium oxalate solutions are used as desensitizing agents.The oxalate ions react with calcium ions in the dentinal fluid to forminsoluble calcium oxalate crystals that are deposited within the tubules.Corticosteroids :Myjor and Ferseth have reported that application of corticosteroidspreparation to dentin caused complete obliteration of tubules thusdecreasing dentin permeability.Bowers and Elliot concluded that 1.2% solution containing 25% by weightthe parachlorophenol, 25% metacrystal acetate, 49% gumcomphor, 1%prednisolone was effective in treatment of sensitivity due to incisal or www.indiandentalacademy.comocclusal fracture, periodontal surgery, occlusal adjustment and post
  62. 62. Iontophoresis is a method of facilitating the transfer of ions by means of anelectrical potential into soft or hard tissues of the body for therapeuticpurposes.The object of fluoride Iontophoresis is to drive fluoride ions more deeplyinto the tubules than can not achieved with topical application of fluoridealone.It is hypothesized that fluoride Iontophoresis may increase theconcentration and depths of penetration of calcium fluoride there byoccluding the tubules and reducing the conduction of hydrodynamicallymediated stimuli.Iontophoresis is not a simple procedure it involves the placement of anegative electrode to dentin and a positive electrode to the patients face orforearm. Although iontophoresis has gained some popularity, its www.indiandentalacademy.com
  63. 63. Lasers :Types used : Argon, Co2, Ho:YAG, Nd:YAG, erbium YAG etc. These systemshave become available which are tailored specifically for dental surgeryusing fibre optic delivery to a hand piece, smaller than a conventionalrotary dental instrument.The availability of laser would potentially satisfy all the requirements of adesnsitizing agent .However question whether laser may be thermally damaging to vital toothstructure has been raised by some investigators.Action :Blocks the tubules probably by fusion of crystals (Hydroxyapatite), as lowintensity defocused beam is used. www.indiandentalacademy.comSide effects :
  64. 64. Burnishing of dentin :Burnishing of dentin with tooth pick or orange wood stick willcreate a partial smear layer on dentin surface, there by occludingthe orifices of dentinal tubules. www.indiandentalacademy.com
  65. 65. www.indiandentalacademy.com
  66. 66. SUMMARY AND CONCLUSIONDentin hypersensitivity is a problem that plagues many patients.The initial or continued clinical cause, in the majority of situations, isgingival recession.The first step should be to identify and eliminate the cause.Patients should be informed of all the possible steps that may be necessaryto eliminate their hypersensitivity.The next is to rectify the recession or seal the exposed dentinal tubulesfrom the oral environment.If the patient is thoroughly informed of all the possible steps then theybecome a partner in the treatment process, identifying for the dentist whenthey want to proceed to the next step.This minimizes frustration on the patients part and facilitates the process www.indiandentalacademy.comby which the dentist solves the problem.
  67. 67. REFERENCESwww.indiandentalacademy.com

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