5. Internal Bleaching Flashcards
Etiology of Tooth Discoloration
• Various etiologies for discoloration.
• “Any change in the hue, color, or translucency of a tooth due to any cause.”
• Great differences in severity, localization, and appearance.
• ____ discolorations are incorporated into the tooth structure.
• ____ discolorations are attached to the tooth surface.
• Intrinsic and extrinsic discolorations may exist in ____ and can affect enamel, dentin, or the pulp.
• Tooth discolorations may be ____, related to patient behavior, age, and disease, or caused iatrogenically by dental and medical treatment.
Before conduct any type of procedure need to know ‘what happened to this tooth’
• What is reason that have the problems that have in teeth/mouth?
○ Need to know etiology of discolorations:
• Can be any changes in hue, color, translucency, etc.
Can have both intrinsic and extrinsic discoloration: • Intrinsic is incorporated into the tooth structure
○ Internally involved
• Extrinsic is the tooth surface
^based on which can figure out whether should address via internal bleaching or external bleaching
• External bleaching can be done at home, bleaching applied to tooth ____
• Internal bleaching bleaching agent applied ____ of tooth
○ Inside dentin and pulp chambers
instrinsic
extrinsics
combination
hereditary
surface
inside
Extrinsic discoloration can be: • Black • Brown ○ \_\_\_\_ causes brown discoloration • Sometimes used by perio if trying to target periodontitis or even for endo, prescribe .12% chlorhexidine (aka peridex) oral rinse for specific time • If use for too long (more than 1 week), can cause \_\_\_\_ of tooth color by attaching to tooth surface • Not permanent it is fixable • Yellow • Green
^color often caused by what you drink e.g. coffee, can also be caused by smoke
chlorhexidine
browning
Intrinsic discoloration of multiple teeth:
• most likely occurs during ____ and/or dentin formation during tooth development
enamel
Systemic intrinsic causes
• May have heard about in peds classes
AI, DGI, and DD:
• Affect ____ teeth during tooth development
“Porphyria, erythroblastosis fetalis, all those” are genetic, systemic causes of multiple tooth discoloration
“This is not our real target disease for discoloration but I want you to know what the systemic reasons are”
multiple
Systemic Intrinsic causes
Here are more causes of intrinsic ____ reads list on slide.
We will go a little further about drug related causes.
discoloration
The last chart the “kind of chart endodontists can actually target and fix” (I think she is saying this is the most important chart for endo internal bleaching because it’s intrinsic stains on single teeth which is what endo deals with when doing RCT):
• ____ • Brown • ____ • White
The factors include:
• ____ restoration
• Coronal restoration
• ____ restoration like a filling/obturation material
• Trauma
• ____ caries
These often affect single teeth and discolor them. We can fix these chairside.
We will now go through these factors one by one so we can address what causes these problems and how internal bleaching can fix them.
black yellow amalgam endodontic dental
What causes pulp necrosis?
• Dental caries
• Trauma
○ Trauma can be a real, accidental trauma
○ Trauma can also be iatrogenic for example if the filling was too deep, or if exposed the pulp during treatment
Mechanical, bacteria, and chemical can all be contributing factors that cause pulp necrosis.
If pulp necrosis happens…
• The bacteria start to cause necrosis and the tissue starts to disintegrate and
bacterial products can be released into the pulp chamber
○ These released colored compounds may penetrate the ____ and
start to stain the dentin structures
• Degree of discoloration is directly linked to how long the pulp has
been under ____ without treatment
• The longer the discolored compounds have been in the pulp chamber the greater the ____
• Pulp necrosis can happen without ____
○ This occurs often in older, aged population
○ It creates an inflammatory reaction and patient sometimes doesn’t know why all of a sudden their tooth has turned to yellow or darker brown
• This discoloration can be chief complaint
Long term ____ can cause more darker and more severe discoloration
Success rate of this bleaching is very ____
• We can bleach chemically with bleaching agent
○ Shows long term success rate
○ Can do RCT and internal bleaching
• Will show examples at end of class
dentinal tubules necrosis discoloration pain good
Intrapulpal hemorrhage is mostly associated with impact injury or trauma to the tooth
• Results in disruption of ____and have hemorrhage and lysis of
erythrocytes
○ Certain “blood integration byproducts” we presume the ____ component in the blood can penetrate dental pulp and start to stain surrounding dentin
The stain tends to increase with ____ (similar to pulp necrosis)
• Difference between the two is that:
○ In internal hemorrhage case, the pulp maintains ____ (mostly)
• Over time, the tooth can turn to yellow but the pt still responds to pulp
vitality tests such as:
• ____ test, electric pulp test
• E.g. kid fell and over next few days tooth gets discolored and do pulp vitality tests and get response, your conclusion is that tooth is vital.
- In these cases, there is no need to do ____
- Don’t do RCT just because of discoloration
- BUT if patient INSISTS that they want to fix this discoloration to meet the patients expectation for esthetics ‘you may need to do ____, if patient insists they want to fix the tooth color’
- If you did external bleaching on a case like this, it would not work. You NEED to do ____ bleaching
Internal bleaching success rate in these cases is \_\_\_\_.
blood vessels
iron
time
vitality cold RCT intentional root canal internal high
Calcific metamorphosis
• Another type of the body’s reaction to the trauma
○ The body starts to release a lot of mineralized (
tertiary calcification shrink calcification yellow
vitality RCT external internal veneer
Developmental defects
• Discoloration of enamel and dentin happening during tooth formation
Endemic fluorosis ingesting excessive amount of fluoride during tooth formation
• Produces defect on mineral tissue most likely ____ matrix ○ Results in ____ enamel
• The degree of staining depends on the degree of the ____
○ When the tooth is erupted and the crown has chalky surface this is because of ____ enamel
• The hypoplastic, porous enamel can be more affected by chemicals in
drink and food thus they can easily stain
• To treat this: we can do ____ bleaching but it is more prone to be rediscolored
○ Must inform patient that bleaching might be successful, but may need to rebleach it. Not ____ result especially if drink coffee.
Tetracycline:
• Use in perio clinic often
• In development of tooth, ingestion of tetracycline binds ____ and causes
discoloration in the dentin
○ Can become ____ to dark grey
• Depends on amount and frequency of the tetracycline as well as the patients age and development
• ____ bleaching can be considered but might not be successful because of the very dark color
• Can do ____ bleaching, but again, these teeth are vital so would be getting rid of vitality
Enamel hypoplasia, enamel hypocalcification
• Similar to endemic fluorosis b.c has less developed enamel structure, more porous enamel
○ Can do ____ bleaching but may discolor again as teeth are constantly exposed to chemicals from food and drink
enamel
hypoplastic
hypoplasia
hypoplastic
external
permanent
calcium
dark brown
external
internal
external
These are related to our own dental procedures therefore, they are preventable. You can also plan how to fix it.
You can plan external or internal, and can give more predictable outcome to the patient.
Filling for endo:
• Obturation uses guttapercha and sealers
○ ____ can cause discoloration
• If you get sealers above ____ the color can leach from the material (especially sealers containing zinc oxide eugenol and “plastics”(?)) these sealers can be darker when ‘exposed to the outside’
• These materials can stain the ____
• Must remove material ____ to the gingival margin
• This is why must measure clinical crown length from the gingival margin to the edge of the crown
• Must remove obturation material below the ____ • It depends on what kind of sealer material you use
• Mostly metallic based or ZOEbased material used very hard to bleach these ____ rate not that high
sealers CEJ dentin cervical margin success
Access cavity preps:
• E.g. upper incisors make ____ shape following outline of tooth
○ But some doctors can find the root canal without making that triangle, but rather making small round opening they can still reach apical foramen BUT they often still leave pulp tissue in the chamber
• To remove all of the pulp in the chamber, MUST do the ideal access cavity prep
• ESPECIALLY ____ have pulp horn extending to corner of tooth so can’t do round access, need to do triangular.
• If make access cavity carefully, this can easily be ____
• If do access again, just extend endodontic access and can then do the ____
traingle
upper incisors
avoided
bleaching
nother case of Iatrogenic staining:
• Metallic restorations like amalgam
○ Even if remove the restoration, the color is already very dark • ____ to bleach these restorations
• If want good outcome would probably have to do ____ or coronal restorations to fix
hard
crowns
Composite restorations may leak at the ____
• The margins of composite stain over time and allow the discoloring agents to penetrate into dentinal tubules of the tooth
○ This is microleakage resulting in staining
• The ____ agent cannot fix composite shade!
○ Need to do bleaching ____, then do composite shade based on bleaching
____
• E.g. picture in middle class 3 yellow restoration if pt doesn’t like composite or tooth shade in general, need do bleaching first then composite
margin
bleaching
first
result
First, need to do diagnosis
• Need to first find ____ of discoloration
○ Based on this can plan whether doing external or internal
• Need to manage patients ____ (rate of success, if will need
multiple visits should be discussed at beginning of treatment)
• Vitality tests:
• If tooth is nonvital need to do ____ first prior to internal bleaching
• If RCT already done but coronal restoration is leaking remove the
old ____ and may need to retreat the RCT
Need to record must know the baseline
• Use shade guide to find the baseline of the current color of the tooth
• Want to harmonize the tooth colors so must record adjacent tooth colors
• Take photographs to keep record
etiology
expectations
RCT
material
These cases should NOT be internal bleaching
____ discoloration
• Should do ____ bleaching first
Severe ____
• E.g. severe dentinal caries need to do ____ control first
____ composites
• Bleaching agent cannot change ____ of composite material
superficial enamel external dentin loss cavity discolored shade
Common bleaching agents
____
• One of the most commonly used agents
\_\_\_\_ • Powder stable when dry ○ Mixed with water or hydrogen peroxide and applied to pulp chamber ^oxidizers to use for internal bleaching
superoxol
sodium perborate crystals
Bleaching reactions
Sodium perborate breaks down to sodium “metaborate” (?) and “hydrogen peroxide” ____ cannot understand what she is saying at all here for this sentence (1:00:43).
Sodium perborate is easier to ____ and ____ than hydrogen peroxide “This is the way the tooth gets bleached”
control
safer
Have two major techniques for internal bleaching
Walking bleach technique
• Sodium perborate can be with ____ OR ____
Thermocatalytic technique
• ____ applied in the pulp chamber and heat applied in the chamber
____ can use both of the techniques combined to increase the success rate
• E.g. dark brown, ____ discoloration can use the combined technique
water hydrogen peroxide hydrogen peroxide combination severe
Walking bleach technique
Need to seal the root canal filling material w/____ (like a barrier) to prevent the agent from going into the root canal (difficult to understand her, think this is what she means 1:02:33).
The bleaching agent can only be placed in pulp chamber and then the access cavity is sealed with a ____
• Bleaching agent can be in pulp chamber 27
○ Patient then comes back and you repeat
• Patient may be satisfied with first time, but may need to do it again to get good result
• BUT process should NOT be repeated more than ____ weeks because it can cause weakening of the dentin and spontaneous crown fracturing
glass ionomer
temporary restoration
4
Walking bleach
First step: mix bleaching material
Apply bleaching agent in pulp chamber
• Can use amalgam carrier can apply mixed agent in amalgam carrier and apply in
pulp chamber
Can pack the material against ____ wall because you want to fix color on facial wall
Can then put ____ to make sure there is no leaking • You can know if there is leaking if you see ____
○ Replace the temporary if there are bubbles b.c it means the agent is coming out
Leave bleaching in for ____ days
• After ____ days agent no longer works
○ This is why must replace every ____
facial temporary restoration bubbles 2-7 7 week
Barrier probing
Bleaching agent should be placed ____ CEJ
• You need to make a barrier above CEJ level
○ If there is leaking it can cause problems with the gingiva
You need to measure clinical crown length from incisal edge to the epithelial attachment
• Measure outside from incisal edge to ____
○ Apply material to this same length
• ____ is biological critical landmark if barrier was not properly placed in this area, the bleaching area goes further down into root canal space and can affect this biologically.
above
gingival margin
epithelial attachment
Barrier placement
After access cavity, you know where gutta percha ended so can measure clinical length ended and create space for barrier material
• Remove the guttapercha to ~____mm below CEJ
○ Reason for this: need space for the ____, which is mostly ____
cement (
2
barrier
glass ionomer
Barrier placement
Can use IRM or cavit, but “I prefer to use glass ionomer cement because it has less of a chance of ____”
You make ____mm barrier above the CEJ then prepare the space so that the agent can go in.
leaking
2
Barrier placement
Can use ____, IRM, composite
• But ____ is hard to remove at the end
“____ cement is best option personally”
cavit
composite
glass ionomer
____ is important to prevent leaking
temporary restoration
Thermocatalytic technique
Using hydrogen peroxide to place in the pulp chamber then ____ instrument is used to apply heat
• Heat activates the bleaching agent
○ Due to the heat and high concentration of bleaching agent, this technique can
cause ____
• You need to be selective in cases whether or not you can use this
• E.g. could use for very dark teeth like ____ induced staining
heat
cervical root resorption
tetracycline
You apply the bleaching agent in the chamber then apply heat with heating instrument
• After that, seal it with temporary filling
If you want to combine the techniques, can do this then make the patient go home with ____ agent “that’s walking bleaching”
Heating technique only done ____.
Which technique you use is based on case selection
bleaching
chairside
Thermocatalytic Technique
Cycles of bleaching
Can see ____ changes chairside after you apply heat
• But you need to repeat:
○ Apply ____ seconds and wait, ____ seconds and wait.
○ But this is very high concentration and then you also apply heat so can
cause trauma to the tooth and dentin…
immediate
30
30
Possible complications
____ resorption
• If you don’t make nice barrier, can cause cervical root resorption
• This is the most serious complication that can occur
○ This is why more emphasis is now placed in the barrier.
Can also cause crown ____
Color ____
• If fix discoloration, tooth can then get discolored again and again
____
• We cannot control the bleaching level sometimes can sometimes get
overbleached and is not harmonized with the rest of the teeth
cervical external root
fracture
regression
overbleaching
External root resoprtion prevention
- avoid or minimize ____
- place an adequate ____
- case selection (____ of patient)
- ____ (reversal of pH)
heat
barrier
age
calcium hydroxide
Another possible complication is color regression
• This causes esthetic problems
Reads slide.
Thermocatalytic is more ____, but it can cause more ____
effective
trauma
How we get a successful result:
• The RCT should be good without ____
○ If RCT is poor - chance for the bleaching agent to go through root canal and affect apical tissue
• Case ____ & pt history
• Proper ____ of pt
○ Know about their realistic ____
• Have good communication w/the pt
• They should know there is possible failure, especially if they expose oral cavity to coffee, smoking, etc.
• Location, shape, thickness
○ Placing below CEJ, prevent leaking, prevent root resorption
leaking
selection
counseling
expectations
Restore permanently with composite resin
• If you want to achieve a brighter color, can apply ____ color than original dentin
shade Reads slide.
Bullet point 3: (should not be repeated more than ____ weeks)
• Can cause weakening of the tooth and external root resorption if done for too long
Recall pt every ____ months:
• Always chance for discoloration to happen again
brighter
4
6
Tooth 8 discolored compared to other teeth
• Trauma to tooth when 8 years old, RCT done at 12 years old, then tooth retreated when 16 years old tooth already treated twice
○ Can see root canal area much wider for tooth 8 than tooth 9
• She was traumatized when young and also retreated this is why root canal and filling is very large
• Cervical area dentin is very ____
○ Remaining tooth is very weak and prosth denied to do crown restoration only option for fixing was ____ bleaching
thin
internal
- Accesses cavity, removes old composite
- Measures clinical crown (can measure before apply ____):
“____ remains as barrier”
____ side is the side the bleaching agent should do its work
○ The bonding agent is therefore removed from this surface They then make resin barrier:
They mix sodium perborate with water and apply with amalgam carrier
They try to apply this agent toward the ____ surface condense it toward facial surface
They then temporize with glass ionomer cement
rubber dam
composite resin
facial
facial
Has two things:
• ____ with the teeth
• Dislikes the ____
Decided to do retreatment and address discoloration
Can see dark, gray discoloration cervically
Radiograph: tooth 7 has large lesion
• The CBCT showed that it penetrates the cortical bone it is a large lesion
• The RCT is not great quality not ideal obturation
pain
color
Can see the gutta percha is very wide - can also see the barrier material that was made with glass ionomer cement
After just one cycle, can see that they gained A2 shade - very dramatic result
When you do the internal bleaching, you need to make sure you do a good ____, make a ____, and apply bleaching agent without ____. You then can repeat the bleaching process.
***“I try to mention everything in this lecture that will be on the exam. Sometimes I have heard students complain “it’s not on the slide but there was exam question” so I like to communicate with you more information that I present in the room
RCT
barrier
leaking
