ODP test #2 questions and answers
Whitening - Preventive and Therapeutic Benefits - Answer -Cosmetic dentistry is
emerging as a health service
• Appearance is an important aspect of nonverbal communication
• Self-perceived attractiveness, including dental esthetics, promotes psychological well-
being and self-confidence
• Social and psychological research has shown that: attractive individuals have
significant advantages (e.g. employment opportunities, earning potential, personal
happiness, overall mental/physical health)
Vital Vs Nonvital Bleaching - Answer -• Vital
• Whitening that occurs with teeth that have a living pulpal tissue
• Nonvital
• Whitening a single tooth that does not have a living pulpal tissue and ceases to give
response to electrical stimuli or temperature changes
Nonvital Bleaching - Answer -Option 1
• Removal of the restoration from the endodontic access cavity
• A 30% to 35% hydrogen peroxide solution or gel is placed in the pulp chamber on a
saturated cotton pellet
• A hot instrument is plunged into the cotton several times to activate the peroxide
Option 2
• "Walking bleach technique"
• A paste/gel containing water and 30-35% hydrogen peroxide is sealed into the pulp
chamber using a temporary restoration
• the patient returns in 2 to 7 days, the whitening material is removed, and a composite
or amalgam restoration is placed in the endodontic access cavity
Mechanism of Bleaching in Vital Teeth - Answer -- Darker teeth take more time to
lighten
- Each tooth reaches a maximum colour change
- Bleaching products cause teeth to become dehydrated
- Colour will stabilize approx 2 weeks after bleaching
Bleaching - Assessment Considerations - Answer -The following factors will be
considered:
• The condition of the dentition; including carious lesions, fractures, pulpal exposures
,• The presence of restorative dental materials which may react to the carbamide and
hydrogen peroxide whitening agents:
- amalgams
- temporary restorations may change colour
- carbamide peroxide may reduce the bond strength of resin composite systems to
treated enamel and dentin; postpone restorative tx for 2 weeks
- patients with crowns, bridges, implants and composite restorations in the anterior teeth
The current level of tooth sensitivity:
• Histological pulpal changes generally show a reversal of the changes and repair within
60 to 92 days
• Patients with recession and exposed cementum are not ideal candidates - if they do
whiten their teeth how can we minimize their sensitivity?
The etiology, intensity and depth of the tooth discolouration:
• Which type of discolourations respond best to bleaching agents?
• Improved results can be obtained with the more challenging intrinsic stains with in-
office bleaching system
• The DDS may also choose to treat fluorosis discolourations with a micro-abrasive
slurry, either alone, or in combination with a tooth bleaching
The periodontal status, which may affect the incidence and degree of soft tissue
irritation:
• Patients should be free of gingival inflammation and periodontal disease
• Presence of soft and hard deposits:
- these deposits need to be removed from the teeth before the trays are placed in order
to achieve optimal whitening
Restorative status:
- whitening may want to be performed prior to placing veneers or composite resins
Dentition:
- when tooth whitening is performed on children, the process must be monitored very
closely
- deciduous teeth are a particular concern for accelerated sensitivity
Mechanism of Bleaching in Vital Teeth - Answer -- Bleaching products penetrate
enamel and dentin reaching the pulp within 5-15 minutes
- Bleaching products breakdown larger organic molecules into smaller, less pigmented
particles
- Oxygen is released from product and alters the optical qualities of the tooth colour
- Colour of both enamel and dentin are changed
Vital Tooth Whitening Materials - Answer -Hydrogen Peroxide
• Used directly or produced through a chemical reaction
• Has a lower pH than carbamide peroxide, which may result in demineralization or
erosion when used for longer treatment times than recommended
, • May result in dentin changes which never recover
• Takes less time per day, but more days to change tooth color effectively
• Higher concentrations of hydrogen peroxide may result in greater sensitivity and more
color relapse after termination of bleaching
Carbamide Peroxide
• Active agent in most bleaching systems in a 10% concentration
• Breaks down into hydrogen peroxide and urea
• Urea may further break down into ammonia with high pH to facilitate bleaching.
• Has slow release: 50% of peroxide released in 2-4 hours and remainder of peroxide in
2-6 hours resulting in less sensitivity
• At neutral pH, 10% solution is both safe and effective
• Takes fewer days but more contact time to change tooth color effectively
Other Ingredients - Answer -Desensitizers Materials to reduce the sensitivity side effect
of bleach-ing may be added to bleaching systems
Materials can be:
• Incorporated into the bleaching gel
• Applied to teeth before bleaching
• Given for use in trays before, during, and after treatment
Material used:
• Potassium nitrate: creates a calming effect on pulp by affecting the transmission of
nerve impulses
• Sodium fluoride: aid in remineralization
• Calcium phosphate and amorphous calcium phosphate: aid in remineralization
• Carbopol: a water-soluble resin used as a thickening agent, which:
• Prolongs the release of hydrogen peroxide from carb-amide peroxide.
• Promotes quicker results
Glycerin: a gel to thicken and control the flow of bleaching agent to prevent
overextending onto gingival tissues
Sodium hydroxide: a cleaning agent
Surfactants: help to lift and remove extrinsic stains
Flavoring: aids in patient satisfaction and compliance
Planning Considerations - Answer -Hydrogen peroxide vs Carbamide peroxide?
- "High and fast" Vs. "Low and slow"
Home versus in-office treatment versus a combination
Whitening - Preventive and Therapeutic Benefits - Answer -Cosmetic dentistry is
emerging as a health service
• Appearance is an important aspect of nonverbal communication
• Self-perceived attractiveness, including dental esthetics, promotes psychological well-
being and self-confidence
• Social and psychological research has shown that: attractive individuals have
significant advantages (e.g. employment opportunities, earning potential, personal
happiness, overall mental/physical health)
Vital Vs Nonvital Bleaching - Answer -• Vital
• Whitening that occurs with teeth that have a living pulpal tissue
• Nonvital
• Whitening a single tooth that does not have a living pulpal tissue and ceases to give
response to electrical stimuli or temperature changes
Nonvital Bleaching - Answer -Option 1
• Removal of the restoration from the endodontic access cavity
• A 30% to 35% hydrogen peroxide solution or gel is placed in the pulp chamber on a
saturated cotton pellet
• A hot instrument is plunged into the cotton several times to activate the peroxide
Option 2
• "Walking bleach technique"
• A paste/gel containing water and 30-35% hydrogen peroxide is sealed into the pulp
chamber using a temporary restoration
• the patient returns in 2 to 7 days, the whitening material is removed, and a composite
or amalgam restoration is placed in the endodontic access cavity
Mechanism of Bleaching in Vital Teeth - Answer -- Darker teeth take more time to
lighten
- Each tooth reaches a maximum colour change
- Bleaching products cause teeth to become dehydrated
- Colour will stabilize approx 2 weeks after bleaching
Bleaching - Assessment Considerations - Answer -The following factors will be
considered:
• The condition of the dentition; including carious lesions, fractures, pulpal exposures
,• The presence of restorative dental materials which may react to the carbamide and
hydrogen peroxide whitening agents:
- amalgams
- temporary restorations may change colour
- carbamide peroxide may reduce the bond strength of resin composite systems to
treated enamel and dentin; postpone restorative tx for 2 weeks
- patients with crowns, bridges, implants and composite restorations in the anterior teeth
The current level of tooth sensitivity:
• Histological pulpal changes generally show a reversal of the changes and repair within
60 to 92 days
• Patients with recession and exposed cementum are not ideal candidates - if they do
whiten their teeth how can we minimize their sensitivity?
The etiology, intensity and depth of the tooth discolouration:
• Which type of discolourations respond best to bleaching agents?
• Improved results can be obtained with the more challenging intrinsic stains with in-
office bleaching system
• The DDS may also choose to treat fluorosis discolourations with a micro-abrasive
slurry, either alone, or in combination with a tooth bleaching
The periodontal status, which may affect the incidence and degree of soft tissue
irritation:
• Patients should be free of gingival inflammation and periodontal disease
• Presence of soft and hard deposits:
- these deposits need to be removed from the teeth before the trays are placed in order
to achieve optimal whitening
Restorative status:
- whitening may want to be performed prior to placing veneers or composite resins
Dentition:
- when tooth whitening is performed on children, the process must be monitored very
closely
- deciduous teeth are a particular concern for accelerated sensitivity
Mechanism of Bleaching in Vital Teeth - Answer -- Bleaching products penetrate
enamel and dentin reaching the pulp within 5-15 minutes
- Bleaching products breakdown larger organic molecules into smaller, less pigmented
particles
- Oxygen is released from product and alters the optical qualities of the tooth colour
- Colour of both enamel and dentin are changed
Vital Tooth Whitening Materials - Answer -Hydrogen Peroxide
• Used directly or produced through a chemical reaction
• Has a lower pH than carbamide peroxide, which may result in demineralization or
erosion when used for longer treatment times than recommended
, • May result in dentin changes which never recover
• Takes less time per day, but more days to change tooth color effectively
• Higher concentrations of hydrogen peroxide may result in greater sensitivity and more
color relapse after termination of bleaching
Carbamide Peroxide
• Active agent in most bleaching systems in a 10% concentration
• Breaks down into hydrogen peroxide and urea
• Urea may further break down into ammonia with high pH to facilitate bleaching.
• Has slow release: 50% of peroxide released in 2-4 hours and remainder of peroxide in
2-6 hours resulting in less sensitivity
• At neutral pH, 10% solution is both safe and effective
• Takes fewer days but more contact time to change tooth color effectively
Other Ingredients - Answer -Desensitizers Materials to reduce the sensitivity side effect
of bleach-ing may be added to bleaching systems
Materials can be:
• Incorporated into the bleaching gel
• Applied to teeth before bleaching
• Given for use in trays before, during, and after treatment
Material used:
• Potassium nitrate: creates a calming effect on pulp by affecting the transmission of
nerve impulses
• Sodium fluoride: aid in remineralization
• Calcium phosphate and amorphous calcium phosphate: aid in remineralization
• Carbopol: a water-soluble resin used as a thickening agent, which:
• Prolongs the release of hydrogen peroxide from carb-amide peroxide.
• Promotes quicker results
Glycerin: a gel to thicken and control the flow of bleaching agent to prevent
overextending onto gingival tissues
Sodium hydroxide: a cleaning agent
Surfactants: help to lift and remove extrinsic stains
Flavoring: aids in patient satisfaction and compliance
Planning Considerations - Answer -Hydrogen peroxide vs Carbamide peroxide?
- "High and fast" Vs. "Low and slow"
Home versus in-office treatment versus a combination
