Chapter 41: Dentinal hypersensitivity Flashcards
pain elicited by a stimulus and alleviated upon its removal. Numerous types of stimuli can lead to pain response in individuals with exposed dentin surfaces.
dentinal hypersensitivity
contact with toothbrush and other oral hygiene devices, eating utensils, dental instruments, and friction from prosthetic devices such as denture clasps.
tactile reaction
temperature change caused by hot and/or cold foods and beverages, and cold air as it contacts the teeth. Cold is the most common stimulus for pain.
thermal reaction
dehydration of oral fluids as from high-volume evacuation or application of air to dry teeth during intraoral procedures.
Evaporative reaction
alteration of pressure in dentinal tubules through a selective membrane.
osmotic
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; acidic formulation of whitening agents.
chemical reaction
Characteristics of Pain from Hypersensitivity
Sharp, short, or transient pain with rapid onset.
Cessation of pain upon removal of stimulus.
Presents as a chronic condition with acute episodes.
Pain in response to a non-noxious stimulus, one that would not normally cause pain or discomfort.
Discomfort that cannot be ascribed to any other dental defect or pathology.
The 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 or from the pulp to the dentinocementum junction
dentin
Only the portions of the dentinal tubules closest to the ___ are potentially innervated with ______ endings from the pulp chamber.
pulp
nerve fiber
Tubules are ____ and more numerous in _____ areas
wider
sensitive
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
pulp
_____ fiber endings extend just beyond the dentinopulpal junction4 and wind around the odontoblastic processes. However, not all dentinal tubules contain _____.
nerve
Nerves react via the same neural ______ (sodium–potassium pump), which characterizes the response of any nerve to a stimulus.
neural depolarization mechanism
As a result of the lower mineral content of _____ & _____ compared with enamel, demineralization occurs more rapidly and at a lower critical pH.
cementum and dentin
Acute hypersensitivity may occur with sudden dentin exposure since gradual exposure allows for the development of natural desensitization mechanisms such ___________ or ________
as smear layer or sclerosis
Loss of enamel or cementum can expose ____ gradually or suddenly as in tooth fracture.
dentin
The occurrence of gingival recession has a multifactorial etiology. Potential causes include:
Effects of improper oral self-care:
- Use of a medium- or hard-bristle toothbrush
- Frequent, long-term aggressive use of the toothbrush and/or other oral hygiene devices.
Enamel and cementum do not meet at the _________ ____ in about __-__% of teeth, leaving an area of exposed dentin.
cementoenamel junction
5-10 %
can occur due to parafunctional habits such as bruxing.
attrition
Effects of attrition and abrasion are exacerbated when ___ erodes the tooth surface or when the tooth is brushed immediately after consumption of acidic foods and beverages.
acid
Dietary acid intake results in an immediate drop in oral pH; after normal salivary neutralization, a physiologic pH of __ reestablishes within minutes
7
a wedge-shaped cervical lesion, has a questionable etiology.
A cervical lesion caused by lateral/occlusal stresses or tooth flexure from bruxing.
Microscopic portions of the enamel rods chip away from the cervical area of the tooth resulting in loss of tooth structure
abfraction
Lateral occlusal forces stress the enamel rods at the cervical area, resulting in enamel rod fracture over time. In an advanced stage, a wedge- or V-shaped cervical lesion is visible. Although minute cracks in the enamel rods may not be clinically evident, the tooth can exhibit hypersensitivity.
process of abfraction
currently accepted mechanism for pain impulse transmission to the pulp as a result of fluid movement within the dentinal tubule, which stimulates the nerve endings at the dentinopulpal interface.
hydronamic theory
Hypersensitivity can decrease naturally over time, even without treatment interventions.
These mechanisms include the following:
- Sclerosis of dentin
- Secondary dentin
- Smear layer
- Calculus
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 intratubular or 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.
sclerosis of dentin
dentin that is secreted slowly over time after root formation to “wall off” the pulp from fluid flow within dentinal tubules following a stimulus; results in narrower pulp chamber and root canals.
secondary dentin
With aging, secondary dentin accumulates, resulting in a _______ chamber with fewer _____ _____ and less sensitivity.
smaller pulp
nerve endings
Consists of organic and inorganic debris that covers the dentinal surface and the tubules.
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 a natural “bandage” that blocks stimuli.
smear layer
Provides a protective coating to shield exposed dentin from stimuli.
Postdebridement sensitivity can occur after removal of these deposits; dentinal tubules may become exposed as this is removed.
calculus
at what age is dental sensitivity more common?
30-40 year olds
Gingival recession is more prevalent with aging. However, dentinal _________is not more prevalent with aging.
hypersensitivity
Hypersensitivity has been reported to occur primarily at the cervical one-third of the facial surfaces of _______ and ________ _______or on premolars and molars
premolars and mandibular anterior teeth
reduction of the resting potential of the nerve membrane so that a nerve impulse is fired. At rest, the inner surface of the nerve fiber is negatively charged and impermeable to sodium ions
Neural depolarization mechanism (sodium/potassium pump)
Loss of tooth structure rarely develops from a single cause but rather from a combination of contributing factors.
t or f
true
The degree of pain is always proportional to the amount of recession, the percentage of tooth structure loss, or to the quality or quantity of stimulus.
t or f
FALSE. it is not always proportional.
Hypersensitivity can manifest as
acute or chronic pain
When patients have difficulty describing and localizing their pain, the following diagnostic techniques and tests can aid in differentiating among the numerous causes of tooth pain.
- Visual assessment
- Palpation
- Occlusal examination
- Radiographic assessment
- Percussion
- Pain from biting pressure
- Mobility testing
- Transillumination
- Pulpal pathology assessment with thermal or electric pulp tests.
There are two basic treatment goals:
- Pain relief
- Modification or elimination of contributing factors.
In the presence of dental biofilm, the dentinal tubule orifices increase to ____times the original size; with reestablishment of biofilm control measures, there is a __% decrease in size
three
20%
an individual using a manual toothbrush typically exerts ____ g of pressure; _____ of pressure is usually exerted with a power toothbrush
200–400
70–150 g
Desensitizing agents can be categorized according to their mechanisms of action, either _________ or _________ . Potassium salts are the only agents that are theorized to work by depolarization.
depolarization of the nerve
occlusion of the dentinal tubule.
Formulations containing _______
______
______ or
_____reduce depolarization of the nerve cell membrane and transmission of the nerve impulse
-Potassium chloride,
-Potassium nitrate,
-Potassium citrate,
or
-Potassium oxalate
Block open dental tubules.
Oxalate salts such as potassium oxalate and ferric oxalate precipitate calcium oxalate crystals to decrease the lumen diameter.
oxalates
Coagulates proteins and amino acids within the dentinal tubule to decrease the dentinal tubule lumen diameter.
Can be combined with hydroxyethylmethacrylate, a hydrophilic resin, which seals tubules.28
Creates calcium crystals within the dentinal tubule to decrease the lumen diameter
Glutaraldehyde
Advocated for use as a caries control agent to reduce demineralization and increase remineralization by releasing calcium and phosphate ions into saliva for deposition of new tooth mineral (hydroxyapatite).
can compromise the bioavailability of fluorides since calcium and fluoride react to form calcium fluoride.
May be effective for patients with poor salivary flow and consequent deficient calcium phosphate levels.
Calcium Phosphate Technology
_% ____ _____ , sodium fluoride, or ______ _____ separately or in combination are the active desensitizing agents
5%
potassium nitrate
stannous flouride
Gels containing _____ ppm fluoride are a prescription product brushed on for generalized hypersensitivity or burnished into localized areas of sensitivity.
5000
Mouthrinse containing ___ % stannous fluoride mouthrinse can be prescribed for daily use to treat hypersensitivity.
Short-term use
(2–4 weeks) will limit staining concerns.
0.63%
A tray delivery system can be used to apply a __% neutral sodium fluoride solution.
Select trays of adequate height and fill with sufficient fluoride agent to cover the cervical areas of each tooth.
2%
A __% _____ ______ ______ maintains prolonged contact with the tooth surface by serving as a reservoir to release fluoride ions in response to pH changes in saliva and biofilm.
Does not require a dry tooth surface,
5%
sodium flouride varnish
Glass ionomer may be placed in the presence of _____ , which eliminates the need for drying the tooth.
In addition to the glass ionomer restoration physically blocking the dentinal tubule, there is an added benefit of _____ _____ _____ .
moisture
slow fluoride release
Desensitization agents and oral self-care measures disrupt the pain transmission as described by the hydrodynamic theory in one of two ways
Prevent nerve depolarization
Prevent a stimulus from moving the tubule fluid by occlusion of dentin tubule orifices
Obturates the tubule opening and does not require use of acid etch or dehydration; a single application may protect against further erosion for 3–6 months.
Methylmethacrylate polymer is a common dentin sealer.
dentin bonding agents
