L2: Tooth Whitening-Part I Flashcards
1
Q
Tooth Whitening today:
A
- Toothpastes
- Do it yourself (DIY)
- Non – vital tooth whitening
- In office
- Take home
- Assisted
- Over the counter (OTC)
2
Q
Diagnosis and Tx planning:
A
Nature of the discoloration.
- Intrinsic stains
- Extrinsic stains
- Expectations of the patient.
- Restorative status.
- Caries status.
- Vital or non vital tooth discoloration (single dark tooth)
- Root exposure
3
Q
Extrinsic vs Intrinsic discoloration:
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/383/616/214/a_image_thumb.png?1652127610)
4
Q
Chromophore theory:
A
- H2O2 interacts with organic chromophores within the tooth structure.
- When H2O2 encounters stain molecules, the chromophore chains are oxidized and converted into simpler structures or alter their optical properties and diminish the appearance of the stain.
- H2O2 diffuses easily all over dentin, interacts with chromophors and changes the color.
- Whitening effect is time and dosage dependent.
5
Q
HP vs CP:
A
![](https://s3.amazonaws.com/brainscape-prod/system/cm/383/616/343/a_image_thumb.png?1652127694)
6
Q
Safety of tooth whitening:
A
- H2O2 produces hydroxyl free radicals that are associated with toxic effects. Results in animal studies vary.
- Accidental consumption resulted to death in humans.
- Stomach and chest pain.
- No evidence of carcinogenicity.
- H2O2 is a tissue irritant, concentration dependent.
- Mild to moderate changes can happen to enamel and dentin.
- Concentration, time and pH dependent.
- Other studies show that these effects can be reversible.
- Most studies are in-vitro.
- It does not appear to have any clinical evidence of problems.
7
Q
Safety of tooth whitening: Approval:
A
- Over 500 research projects in 50 years document the safety of HP and CP in tooth whitening concentrations in humans.
- Carbamide Peroxide: FDA approved since 1974
- Whitening Products: ADA approval since early 90s.
- Since 1989, in millions of tooth whitening cases, there is no published case reports with erosion or any other non reversible problems.
8
Q
Tooth whitening and Dental materials:
A
- Controversial in-vitro studies show possible effects on:
- Surface roughness
- Microhardness
- Color
- Microleakage.
- No evidence of a lower clinical performance of Dental materials exist.
9
Q
Adverse effects:
A
- Cold/air sensitivity in up to 80% of the patients.
- Due to dehydration mainly.
- Mild to severe.
- Gingival tissue irritation.
- Mechanical trauma.
- Toxic effect.
- Pulpal effects.
- H2O2 definitely reaches the pulp.
- The lower the concentration the faster the regeneration
- Decrease in Enamel and Dentin Bond Strengths Immediately After Whitening.
- REVERSIBLE IN A FEW DAYS
10
Q
Vital Tooth Whitening:
A
- In office
- Take home
- Assisted
- Over the counter (OTC)
- Whitening Toothpastes
- Do it yourself(DIY)
11
Q
OTC Whitening:
A
- TV, drug stores.
- Some contain citric Acid, titanium dioxide, and other potentially DANGEROUS PRODUCTS.
- Not customized trays.
- Report of serious enamel erosion (CubbonT, Ore D, 1991)
- Not approved by any dental organization
MOST IMPORTANT, THERE IS NO DENTIST SUPERVISION
12
Q
Whitening Toothpastes:
A
- Very low concentration of H2O2 to work.
- High abrasiveness.
13
Q
Case Selection: Indications :
A
- Teeth of a uniform color.
- Few restorations.
- The Shade before whitening does not matter.
- Tetracycline discoloration ???
- Fluorosis ???
- White spots
14
Q
Case Selection Contra- indications:
A
- Caries or Periodontal problems.
- Cervical abrasions or erosions.
- Large aesthetic restorations.
- Pregnancy and breast feeding.
- Children.
15
Q
Two parameters effect the results:
A
- Contact time
- H2O2 concentration