Tooth hypersensitivity - learn about why teeth are sensitive to cold and other stimulus including (sensitivity theories - causes and factors causing the teeth to be sensitive) حساسية الاسنان - تعرف لماذا الاسنان حساسة للبرودة وللمؤثرات الاخرى هذا الموضوع يتضمن (نظريات حساسية الاسنان - الاسباب التي تجعل الاسنان اكثر حساسية) Prepared by: Dr Muneera Ghaithan

1. Dentin hypersensitivity

2. prepared by: Dr. Muneera Ghaithan
Dentin
hypersensitivity

3. definition
It’s defined as sharp ,short pain arising from
exposed dentin in response to stimuli typically
thermal, chemical, tactile or osmotic and
which can not be ascribed to any other form
of dental defect or pathology.
It’s a symptom complex rather than a true
disease

4. Mechanism of
Dentinal Sensation

5. The neurophysiology of teeth
• Both myelinated and unmyelinated axons
innervated the pulp.
• According to conduction velocities the nerve
units can be classified into:
A group
C group
Having conduction velocity
> 2 m/s
Having conduction velocity
< 2 m/s

6. • Aδ fibers ( C.V≈6-30 m/s) are responsible for
sharp better localized pain.
• While C fibers are considered responsible for
dull radiating pain
Myelinated A fiber seems to be responsible
for dentin sensitivity.

7. • It is well known even the most peripheral
part of dentin is sensitive. However,
varying opinions have been presented on
the mechanism of intradental nerve
activation in response to external
irritation.

8. Mechanism of dentin sensitivity
Theories of dentin sensitivity:
A. Neural theory
B. Odontoblastic theory
A. The hydrodynamic theory
B. Modulation theory

9. Neural theory
Activation to initial excitation of
these nerve ending in dentinal
tubules
nerve signals are conducted
along the parent primary
afferent nerve fibers.
Dental nerve branch.
brain

10. a recent neuroanatomic studies -
Byer (1984) have shown that
only the inner 100 to 200 µm of
dentin is innervated, indicating
that the pain sensations induced
by stimulation of superficial
dentin cannot be a result of
direct irritation of nerve ending.

11. Odontoblastic theory
The theory assumed that odontoplast
extend to the periphery.
Stimuli
Excite the process or body of
odontoplast.
The membrane of odontoblasts come
into close apposition with that of the
nerve ending in the pulp or in D.T.
The odontoblast transmets the
excitation of these nerve endings

12. Thomas (1984) indicated that the
odontoblastic process is restricted to the inner
third of the dentinal tubules. Accordingly it seems
that the outer part of the dentinal tubules
doesnot contain any cellular elements but is only
filled with dentinal fluid.

13. The hydrodynamic theory
This theory proposes that:
Stimuli
Displacement of fluid that exists
in the dentinal tubules
Activates the nerve endings
present in the dentin or pulp

15. The displacement of
the tubule contents
is rapid enough to
deform nerve fiber in
pulp or predentin or
damage odontoplast
cell. Both of these
effects appear
capable of producing
pain.

16. Mathews et al (1994)

17. Etiology and predisposing factors
The primary underlying cause for DH is exposed
dentin tubules
Dentin may be
exposed by:
Loss of covering periodontal
structures
Loss of enamel

18. The area of recession that has developed due to a combination
of age-related changes, and history of gum disease (light blue).
The dark blue area has a white filling which may have been
placed there to treat dentine hypersensitivity.

19. Common Reasons for Gingival
Recession
1. Inadequate attached gingiva
2. Prominent roots
3. Toothbrush abrasion
4. Pocket reduction periodontal surgery
5. Oral habits resulting in gingival laceration, i.e.,
traumatic tooth picking eating hard foods
6. Excessive tooth cleaning
7. Excessive flossing
8. Gingival loss secondary to specific diseases, i.e.
periodontitis, herpetic gingivostomatitis
9. Crown preparation

20. Causes of loss of enamel:

21. anatomical characteristics in the region
of cementum–enamel junction (CEJ),
edge-to-edgeoverlapping not form a junction

22. Diagnosis
The pain arising from DH is extremely variable
in character, ranging in intensity from mild
discomfort to extreme severity.
The degree of pain varies in different teeth and
in different persons.
It may emanate from one tooth or several teeth
and it is sometimes felt in all quadrants of the jaws

23. Most patients describe the pain arising from
DH as being rapid in onset, sharp in character,
and of short duration ( the character of pain
doesn't outlast the stimulus).
The pain is intensified by thermal changes,
sweet, sour, scratching the dentine.

24. Diagnosis and treatment
Making the proper diagnosis is the first step in
assisting your patients suffering from dentin
hypersensitivity.

25. Differential diagnosis
1. Chipped teeth.
2. Fractured restoration.
3. Restorative treatment.
4. Dental caries.
5. Cracked tooth syndrome.
6. Other enamel invaginations.

26. • Addressing any underlying causes of dentin
hypersensitivity is the first step in successfully
managing the condition.
• Educating the patient on the causes and
management of dentinal hypersensitivity.
• Treatment options include both in-office
procedures and at-home care.
Management and Treatment
Generally, the least invasive treatment method
should be considered first.

27. • Three principal treatment options:
1. Dentinal tubules can be covered
2. Dentinal tubules can be plugged
3. Desensitization of the nerve tissues
within tubules
Management and Treatment

28. At-home treatments:
• At-home treatments include desensitizing
toothpastes or dentifrices
1. Desensitize the nerve
a)Potassium Nitrate:
Management and Treatment
interfere with the transmission
of the nerve impulse
Potassium nitrate is commonly
used in toothpastes such
as Sensodyne or Crest
Sensitive as a remedy

29. 2. Plug (sclerose) the dentinal tubules:
a) Strontium chloride and strontium acetate
form mineralised deposits
within the tubule lumen and
on the surface of the exposed
dentine, they are used in
Sensodyne Original and
Sensodyne Mint toothpastes.
Note the occlusion of the dentinal tubules,
preventing the outward flow of fluid and
subsequent stimulation of nerve fibers.
Management and Treatment
b) Fluoride dentifrices

30. In-office procedures
1- Desensitize the nerve:
potassium nitrate
2- partially obturate the dentinal tubules
a) stannous fluoride.
b) potassium oxalate.
c) strontium chloride.
d) calcium compounds.
Management and Treatment

31. 3- Tubule sealant
• A) restorative resins.
• B) dentin bonding agents.(GLUMA)
4- Cavity varnish
5- Laser

32. Patient education
• Causes of dentinal hypersensitivity
• Instructions on tooth brushing technique and when
to brush.
• Advice on toothbrush type - avoid medium and
hard bristles
• Advice on appropriate use of toothpaste
• Advice on technique for interdental cleaning
• Dietary advice
• Hypersensitivity associated with tooth whitening
Management and Treatment