Chapter 43: Tooth Bleaching Flashcards
may result in significantly whiter teeth and contribute to an increase in patient’s self-confidence.
tooth bleaching
refers to use of abrasive agents and/or detergents contained in a dentifrice to remove extrinsic stain.
tooth whitening
involves free radicals and the breakdown of pigment, which occurs in the tooth-bleaching procedures.
Bleaching
teeth can be stained ________ & _______
intrinsically and extrinsically.
________ bleaching is used for both vital and nonvital teeth.
external tooth
Bleaching agent breaks down chemical bonds in _______ making them refract light and appear lighter.
chromogens
Color change can extend into the _____ to produce a whitened tooth.
dentin
a bleaching procedure performed by a dentist after root canal therapy using a rubber dam or other type of isolation.
Nonvital tooth bleaching
method sealed a mixture of sodium perborate and water into the pulp chamber and retained it there between the patient’s visits.
walking bleach method
the walking bleach method was modified using water and 30%–35% _________ instead of the sodium perborate and water
hydrogen peroxide
Bleaching products penetrate ____ and ____ reaching the pulp10 within ___ minutes.
enamel
dentin
5-15
Bleaching products break down larger pigmented organic molecules, called ______ into smaller, less pigmented constituents that are locked in the enamel matrix and dentinal tubules
chromogens
Dentin color is either ___or _____ and can be seen through the enamel due to its translucency.
yellow
gray
Both _______ and ______ peroxide are used to lighten vital teeth.
hydrogen peroxide and carbamide
_____ is approximately three times stronger than carbamide peroxide
Hydrogen peroxide
_____ has a short working time; _______ has an extended working tim
hydrogen peroxide
carbamide peroxide
Hydrogen peroxide releases all of the peroxide within ___hours.
1.5
Hydrogen peroxide breaks down into_____ and ____ ; carbamide peroxide breaks down into _____ and _____ which further break down as shown
oxygen and water
hydrogen peroxide and urea,
carbamide peroxide Has slow release: __ of peroxide released in ____ hours and remainder of peroxide in ___ hours resulting in less sensitivity.
50%
2-4
2-6
Has a lower pH than carbamide peroxide, which may result in demineralization or erosion when used for longer treatment times than recommended.
hydrogen peroxide
Materials to reduce the sensitivity side effect of bleaching may be added to bleaching systems:
-POTASSIUM NITRATE: creates a calming effect on pulp impulses
-SODIUM FLOURIDE : (aid in remineralization).
-CALCIUM PHOSPHATE and amorphous calcium phosphate
( aid in remineralization)
a water-soluble resin used as a thickening agent, which:
Prolongs the release of hydrogen peroxide from carbamide peroxide.
Promotes quicker results.
carbopool
a gel to thicken and control the flow of bleaching agent to prevent overextending onto gingival tissues.
Glycerin:
help to lift and remove extrinsic stains.
Surfactants
aids in patient satisfaction and compliance.
aids in patient satisfaction and compliance.
a cleaning agent.
Sodium hydroxide
Materials to reduce the sensitivity side effect of bleaching may be added to bleaching systems.
Desensitizers
Both hydrogen peroxide __% and carbamide peroxide __% are considered safe to lighten the color of teeth when professionally monitored
3.5%
10%
Hydrogen peroxide at concentrations of __% or higher may:
Remove the enamel matrix.
Create microscopic voids that scatter light.
Result in increased whiteness until remineralization occurs and color partly relapses.1
30%
Complications with current restorations may include:
- Increased surface roughness.
- Change in surface color.
- Increased microleakage.
Personal factors affecting acceptance for treatment may include:
- Subjective determination when tooth shade is acceptable.
- Patients with unrealistic personal expectations.
- Poor patient compliance with treatment
- Patients with tooth conditions that do not respond to vital tooth bleaching
Tetracycline particles incorporate into _____ & ____ during mineralization of ____teeth.
Result: discolored dentin resistant to bleaching.
dentin calcium
unerupted
First-category staining
light-yellow to light-gray responds to bleaching.
Second-category staining
darker and more extensive yellow-gray responds to extended bleaching time.
Third-category staining:
intense dark gray-blue banding stains.
Severe third-category staining may require porcelain veneers for satisfactory esthetic result.
Some tetracycline stains will require __-__ months to achieve a satisfactory result.
1-12 months
Brown discoloration responsive to bleach __% of the time.
80
Nicotine stains: require __-__ months of nightly treatment due to the tenacity of the stain
1-3 months
Desensitization agents for Bleaching
- toothpaste containing POTASSIUM NITRATE
- toothpaste that includes CALCIUM CARBONATE
- toothpaste, which includes SODIUM FLOURIDE
Root Resorption
Can occur after bleaching, particularly after _________ , ________ bleaching when heat is applied during the technique.
May lead to _______
intracoronal, nonvital tooth
tooth loss
Products containing acidic pH may result in tooth ___over time.
The higher the percentage of hydrogen peroxide, the lower the ___
(More common with OTC bleaching products)
erosion
PH
Professionally applied bleaching is performed with high concentrations of ____ % hydrogen peroxide or ____ % carbamide peroxide.
30-40
35-44
over the counter bleaching preparations :
- strips
- prefabricated trays
- paint on (carbamide peroxide)
- dentrifice
- mouthrinse
Also called walking bleach method and internal bleaching, _______ involves the bleaching of a single, ______ tooth that is discolored.
nonvital tooth bleaching
endodontically treated
bleaching nonvital teeth:
Hydrogen peroxide and/or sodium perborate is placed in the pulp chamber, sealed, and left for - days,
3-7
Three concepts should be considered when determining tooth shade:
hue, chroma, and value
refers to the color of a tooth
hue
refers to the saturation, or intensity of the color.
chroma
the lightness or brightness of the color
value
When selecting tooth shade, it is best to start with selecting the proper ___
value
Each tooth reaches a maximum color change. Additional bleaching product or contact time will NOT necessarily result in a lighter color
true or false
true
Dentin color is either___ or ____ and can be seen through the enamel due to its translucency.
yellow
gray
Both ____ & ____ peroxide are used to lighten vital teeth.
hydrogen peroxide
carbamide
After bleaching, new restorative procedures need to be delayed for __ weeks to allow for color stabilization.
Bonding needs to be delayed for __ weeks due to significantly reduced bonding strength associated with recently bleached tooth surface
2 weeks
2 weeks
Current American Dental Association recommendations for children and adolescent use of tooth bleaching include:
- Delaying treatment until after permanent teeth have erupted.
- Use of a custom-fabricated tray to limit amount of bleaching gel.
- Close supervision.
Tooth bleaching is contraindicated in the following patients:
- PREGNANT and lactating women.
- Use of photosensitive medications
- Recent cosmetic procedures such as skin peels, facial waxing, or use of certain essential oils.
Light-activated bleaching is contraindicated for patients who are:
- Light sensitive.
- Taking a photosensitive medication.
- Receiving photochemotherapeutic drugs or treatments such as psoralen and ultraviolet radiation.
