1. Dentin Hypersensitivity
DH102: Clinic II
Lisa Mayo, RDH, BSDH
Concorde Career College

2. Reference
Wilkins CH43

3. Outline Define dentinal hypersensitivity
Review Anatomy of Tooth Structures
What can cause dentin exposure
Hydrodynamic Theory
Natural Desentization
Desentization Products

4. Objective #1: Define Dentinal Hypersensitivity

5. Dentin Hypersensitivity
Short, sharp painful reaction that occurs when some areas of exposed dentin are subjected to certain stimuli:
Mechanical
Thermal
Chemical

6. Hypersensitivity Patient Concerns Dentinal Hypersensitivity
Hot/cold sensitivity to foods/drinks
Pain during dental appointments: metal instruments can elicit pain
Will ask RDH why they have pain
Dentinal Hypersensitivity
Difficult to diagnose: their pain could be caused by many factors. May not be dentinal sensitivity.
Numerous tx approaches
Pain elicited by a stimulus and alleviated upon its removal

7. Stimuli That Elicit Pain Reaction
Tactile or mechanical
Toothbrushing
Eating utensils
Dental instruments
Friction from prosthetic devises such as denture clasps
Evaporative
Dehydration of oral fluids as from high-volume suction or applying air to dry teeth during intraoral procedures
Thermal
Cold more common than hot

8. Stimuli That Elicit Pain Reaction
Chemical
Acids in foods and beverages such as citrus fruits, condiments, spices, wine, and carbonated beverages
Acids produced by acidogenic bacteria following carbohydrate exposure
Acids from gastric regurgitation
Osmotic
Alteration of osmotic pressure in dentinal tubules due to isotonic solutions of sugar & salt

9. Characteristics of Pain from Hypersensitivity
Pain at onset
Sharp, short, transient pain and rapid onset
Cessation
From pain upon removal of stimulus
Chronic condition w/ acute episodes
Response to non-noxious stimulus (one that would not normally cause pain or discomfort)
Discomfort that cannot be ascribed by another dental defect or pathology

10. Objective #2: Review Tooth Anatomy

11. Anatomy of Tooth Structures
Dentin
Portion of the tooth covered by enamel on the crown and cementum on the root
Composed of fluid-filled dentinal tubules that narrow and branch as they extend from the pulp to the dentinoenamel junction
The only portion of the dentinal tubules that are innervated with nerve fiber endings from the pulp chamber are those closest to the pulp
10% of all teeth have dentin exposure

12. Anatomy of Tooth Structures
Dentin
Tubules in sensitive areas are wider and more numerous
Dentinal tubule closest to the pulp contains an odontoblastic process: thin tail of cytoplasm from a cell in the tooth pulp called an odontoblast
Fluid movement w/in open dentinal tubules can stimulate certain nerve endings that are associated w/ the odontoblastic processes, resulting in a short, sharp pain in the tooth

13. Odontoblastic Process

14. Odontoblastic Process
DENTIN
ENAMEL
DENTIN
Nerves
PULP
Odontoblastic Process

15. Anatomy of Tooth Structures
Pulp
Highly innervated with nerve cell fiber endings that extend just beyond the dentinopulpal interface of the dentinal tubules
Body portions of odontoblasts (dentin-producing cells) located adjacent to the pulp extend their processes from the dentinopulpal junction a short way into each dentinal tubule

16. Anatomy of Tooth Structures
Nerves
Nerve fiber endings extend just beyond the dentinopulpal junction and wind around the odontoblastic processes as shown in the next slide
Nerves react via the same neural depolarization mechanism (sodium potassium pump), which characterizes the response of any nerve to a stimulus

20. Objective #3: What Can Cause Dentin Exposure

21. Mechanisms of Dentin Exposure
General considerations
Once dentin exposed: demineralization of the root surface will occur more rapidly than of the enamel
Lower mineral content
Higher critical pH to initiate demineralization
Acute hypersensitivity may occur with sudden dentin exposure since gradual exposure allows for the development of natural desensitization mechanisms such as smear layer or sclerosis
After many years, secondary & reparative dentin may have formed, which also protects the pulp

22. RECESSION

23. Factors Contributing to Gingival Recession & Root Exposure
Improper oral hygiene self-care
Medium or hard toothbrushes
Aggressive brushing
Improper brushing motion
Anatomy and physiology of area
Anatomically narrow zone of attached gingiva is more susceptible to abrasion that can lead to recession and subsequent cemental exposure
Malocclusion
Tight, short labial frena that pulls on gingival tissues
Subgingival instrumentation
Large amts of sub-g calculus can pull gums away from tooth and create recession
May heal after removal

24. Frenum Pull

25. Factors Contributing to Gingival Recession and Root Exposure
Periodontal disease processes
Junctional epithelium migrates apically in response to inflammatory factors leading to connective tissue breakdown and loss of periodontal attachment
Surgical procedures
Dr’s reduce pocket depths
Gums repositioned
Tooth extraction

26. Factors Contributing to Gingival Recession and Root Exposure
Orthodontic procedures & appliances
Oral habits or piercings
Lip, tongue

27. Factors Contributing to Loss of Enamel & Cementum
Anatomy of cervical area
Thin and easily abraded when exposed
Enamel and cementum do not meet at CEJ in about 10% of teeth
Occlusion
Constant trauma to teeth
When recession present & pt grinds – can cause abfractions
Attrition and abrasion
Mechanical wear
Clenching / Grinding
Erosion
Chemical wear of teeth
From diet such as high acids, citric acids, wine, sodas
Bulimics

28. EROSION

29. ATTRITION

31. ABFRACTION

32. http://www. youtube. com/watch

33. Objective #4: Hydrodynamic Theory

34. Hydrodynamic Theory
Currently accepted explanation for transmission of stimuli from the outer surface of the dentin to the pulp
Developed by Brannstrom (1960s): theorized that a stimulus at the outer aspect of dentin will cause fluid movement within the dentinal tubules
Fluid movement creates a pressure on the nerve endings within the tubule
Transmits pain impulses by stimulating the nerves in the pulp

35. Open Dentinal Tubules

36. Hydrodynamic Theory Explains the following Dentinal tubules exposed
Pain-producing stimuli are present
Pain-producing stimuli initiate the flow of lymphatic fluid within dental tubules
Odontoblasts and their processes act as receptors and transmitters of sensory stimuli
Movement of tubular fluids causes nerve endings in the pupal wall to be stimulated & produce pain

37. Objective #5: Natural Desentization
Sclerosis of dentin (your oral embry book p.101 refers to this as tertiary dentin, reactionary/response, reparative dentin)
Secondary Dentin
Smear layer
Calculus

38. Natural Desensitization
Sclerosis of dentin (tertiary dentin)
Occurs by mineral deposition within tubules as a result of traumatic stimuli, such as attrition or dental caries
Creates a thicker, highly mineralized layer of peritubular dentin (deposited within the periphery of the tubules)
Results in a smaller-diameter tubule that is less able to transmit stimuli through the dentinal fluid to the nerve fibers at the dentinopulpal interface

39. Natural Desensitization
Secondary Dentin
Deposited gradually on the floor and roof of the pulp chamber after teeth are fully developed
Secreted more slowly than primary dentin that formed prior to tooth eruption: both types created by odontoblast
Creates a “walling off” effect between the dentinal tubules and the pulp to insulate the pulp from dentin fluid disturbances caused by a stimulus such as dental caries
As aging occurs, secondary dentin accumulates, resulting in a smaller pulp chamber with fewer nerve endings and less sensitivity

40. Natural Desensitization
Smear layer
Consists of organic and inorganic debris that covers the dentinal surface and the tubule
Accumulates following scaling and root instrumentation, use of toothpaste (abrasive particles), cutting with a bur, attrition, or abrasion
Occludes the dentinal tubule orifices forming a “smear plug” or “bandage” that blocks stimuli
May have a positive or negative effect
It protects from hypersensitivity, but may interfere with reattachment of periodontal tissues

41. Natural Desensitization
Calculus
Provides protective coating to shield exposed dentin from stimuli
Post debridement sensitivity can occur after removal of heavy calculus deposits
Dentinal tubules may become exposed as calculus is removed

42. Patients and Their Pain
Dentinal Hypersensitivity Statistics
Prevalence of hypersensitivity 8-30% of adults
Greatest age to be affected = 20-40yrs
Incidence decreases with increasing age = secondary dentin, sclerosis of dentin
Higher incidence in perio patients

43. Differential Diagnosis
Diagnostic techniques and tests
Visual assessment of the tissues and teeth
Palpitation both extra and intraoral
Ask about sinus issues
Occlusal exam: articulating paper
Radiographic assessment: pulpal pathology? Vertical root fracture?
Percussion: use handle to tap on tooth to see if pain elicited
Mobility?
Pain from biting: Bite Stick, cracked tooth
Transillumination: cracked tooth
Thermal/Electric tests on the pulp: Cold-Test

44. Question
After many years of root exposure, what structure can form that protects the root and pulp?
Primary dentin
Secondary dentin
Reparative dentin

45. Question
After many years of root exposure, what structure can form that protects the root and pulp?
Primary dentin
Secondary dentin
Reparative dentin

47. Objective: Desentization Products

48. Desensitizing Agents and Theorized Mode of Action: Mosby’s
Potassium salts
Formulations containing potassium chloride/nitrate/citrate/oxalate
Reduce depolarization of the nerve cell membrane and transmission of the nerve impulse by occluding dentinal tubules
OTC
Fluorides
Decrease the lumen diameter, block/occlude open dental tubules
Calcium phosphate technology
Caries control to reduce demin and to remineralize by releasing Ca, Phosphate ions for deposition of new tooth mineral (hydroxyapatite)
May occlude dentinal tubule openings

49. Desensitizing Agents and Theorized Mode of Action: Mosby’s
Oxalates
Block open dental tubules
Oxalate salts (potassium & ferric oxalate) decrease the lumen diameter
Glutaraldehyde
Can be combined with HEMA, a hydrophylic resin which seals tubules
Creates Ca-crystals w/in dentinal tubule to decrease the lumen diameter
Arginine and calcium carbonate
Occlusal tubules using arginine (amino acid), bicarbonate, Ca-carbonate
Marketed as a px paste to be applied before instrumentation

50. Types of Desentizing Tx
No single agent or form of tx is effective for all persons
Numerous agents have varying degrees of success
Solutions, gels, pastes of fluoride in varying compounds and %
Adhesive, varnish, bonding materials
Polymerizing agents
Glass ionomer cements (GIC)
Adhesive resin primers
Iontophorectic devises
Laser therapy
Restorations

51. Glass Ionomer Cements Used in cervical abrasion and abfractions
Sensitive area etched with 50% citric acid
Rinse with water
Dry
Glass ionomer placed

52. Adhesive Resin Primers
Reduce dentin permeability by occluding open tubules
Material rubbed on sensitive area for approximately 30 sec and air-dried

53. Iontophoretic Devises
Application of an electric current to impregnate tissues with ions from dissolved salts
Fluoride iontophoresis is thought to result in the increased uptake & penetration of fluoride ions into dentin
Devises are technique sensitive

54. Laser Therapy
One-time tx that reduces or eliminates dentin sensitivity
Seals tubules
Sensitive dentin treated with laser is found to be harder compared with untreated dentin

55. Restorations
Placed on surface where dentin is exposed to help reduce sensitivity
Unfilled or partially filled resins
Covers patent dentinal tubules
Dentin-bonding agents
Obturation of the tubule opening
Composite/glass ionomer

56. Soft Tissue Grafting
Surgical placement of soft tissue grafts can cover a sensitive dentinal surface
Results are somewhat unpredictable
Done with a specialist
High cost to patient

57. Behavioral Changes Dietary modifications
Limit acidic foods and beverages
Evaluate use of dental products: no acid formulations – can contribute to erosion
Avoid hot/cold extremes in the mouth: no ice, coffee not too hot…
Excellent dental biofilm control
Eval toothbrush type and technique
Eliminate parafunctional habits: mouthguard, ortho, occlusal adjustments
Medical referral for acid-reflux / GERD issues, Bulimia suspected
At home fluoride tx

58. FLUORIDE TRAY

59. Dental Professional Measures
Fluoride varnishes
Does not require a dry tooth surface: advantageous since this drying the tooth can be a painful procedure for a patient with dentin hypersensitivity

60. Novamin
Ca and Phosphate ions in ACP will seek out areas of demin and enhance enamel remin., occlude dentinal tubules, increase F uptake, prevent caries progression
High risk caries groups should use
People w/ sensitivity should use
Should be used in combo with F
Toothpaste, polish paste, sealant

61. Recaldent / Casein Phosphopeptides
Enhance the effects of Fluoride & provides a supersaturated environment of Ca and P for remin.
Not a Fluoride substitute
High caries risk, sensitivity issues
Caries prevention
Gum, pastes, professional application

62. Additional Considerations
Tooth-whitening-induced sensitivity
Commonly associated with carbamide peroxide
A reversible pulpitis is caused from the dentin fluid flow and pulpal contact of the material, which changes the osmolarity, without apparent harm to the pulp
Hypersensitivity = few days to several months
Exposed dentin and pre-existing dentin hypersensitivity increase risk for hypersensitivity secondary to whitening
Reduce tooth-whitening-induced sensitivity: Potassium nitrate, fluoride, or other desensitization product prior to & concurrently while whitening

63. Question Novamin is made of which two ions: Calcium, phosphate
Calcium, fluoride
Phosphate, fluoride
Phosphate, Potassium

64. Question Novamin is made of which two ions: Calcium, phosphate
Calcium, fluoride
Phosphate, fluoride
Phosphate, Potassium