Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FINALS - Restorative Dentistry > Tooth Whitening > Flashcards

Tooth Whitening Flashcards

1
Q

What are the extrinsic factors of tooth discolouration?

A
  • Smoking
  • Tannins (Tea, coffee, red wine)
  • Chromogenic bacteria
  • Chlorhexadine
  • Iron supplements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the intrinsic causes of tooth discolouration?

A
  • Fluorisis
  • Tetracycline
  • Non-vitality
  • Dental materials
  • Cystic fibrosis
  • Thalassemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the first stage of whitening for extrinsic tooth staining?

A

PMPR (HPT - hygiene phase therapy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the mechanism by which vital tooth staining occurs?

A

Discolouration is caused by formation of chromogenic products. These are long chain organic molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mechanism by which vital tooth bleaching can occur?

A

Bleaching oxidises the long chain organic molecules, leading to smaller molecules which are often no longer pigmented.

Oxidation can also cause ionic exchange in metallic molecules leading to a lighter colour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does hydrogen peroxide cause tooth whitening?

A
  • Forms an acidic solution in water
  • Breaks down to form hydroxyl
  • Hydroxyl is an oxidising free radical

Note that it is often not used as a bleaching agent for teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the purpose of carbamide peroxide in bleaching gel?

A
  • Active ingredient
  • Breaks down to produce hydrogen peroxide and urea
  • Urea increases and stabilises pH
  • Hydrogen peroxide creates hydroxyl (the oxidising agent)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of carbopol in bleaching gel?

A
  • Thickening agent
  • Slows release of oxygen
  • Increases viscosity of gel, causing it to stay on the tooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What factors impact the effect of external vital bleaching?

A
  • Time (more time, better effect)
  • Cleanliness (the cleaner the better)
  • Concentration (higher conc, quicker effect)
  • Temperature (higher temp, quicker effect)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What factors should you check before starting external vital bleaching?

A
  • Check patient is dentally fit
  • Carious leakage may lead to pulpal damage
  • Take an initial shade, ask patient if they agree, make a note of it.
  • Consider clinical pictures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What advice would you give to the patient about the bleaching process?

A
  • Sensitivity
  • Relapse
  • Restoration colour
  • Allergy
  • Might not work
  • Requires compliance with regime
  • Can cause gingival irriation
  • Problems with bonding to teeth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the disadvantages of chair-side vital external bleaching?

A
  • Takes time
  • Can be uncomfortable
  • Results wear off quicker
  • Expensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the process of chair-side vital external bleaching?

A
  • Thorough cleaning
  • Rubber dam
  • Bleaching gel
  • Apply heat/light
  • Wash/dry/repeat
  • Takes 30-60mins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the effects of heat/light/laser to bleaching?

A
  • Mainly a marketing technique
  • No evidence of better bleaching
  • Often good initial result due to dehydration, but this wears of quickly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the typical strength of a bleaching agent?

A

10-15% carbamide peroxide gel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the process of home vital external bleaching?

A

Patient sent home with custom made tray, and applies gel as per manufacturers guide.

Bleaches slowly over time, but requires patient compliance.

17
Q

What do you tell the patient if their teeth are not whiter within 2 weeks?

A

Whitening is most likely not going to work.

18
Q

What are the indications for tooth bleaching?

A
  • Age related discolouration
  • Mild fluorosis
  • Post-smoking cessation
  • Tetracyclin staining
19
Q

How often is bleaching re-treatment required?

A

Every 1-3 years but this varies.

20
Q

Is there evidence that bleaching can damage teeth long term?

A

No evidence over 15+ years.

21
Q

How does bleaching affect boding?

A

Residual oxygen from the peroxide remains within enamel structure, but dissipates over a short time.

This can interfere with bonding, so it is advisable to delay restorative procedures for 24 hours after bleaching. (Better to delay for a week)

22
Q

What can cause internal non-vital discolouration?

A
  • Dead pulp, bleeding into dentine
  • Blood products darken and diffuse
  • Causes grey discolouration.
23
Q

What are the contraindications for internal non-vital bleaching?

A
  • Heavily restored teeth
  • Staining due to amalgam
24
Q

What are the limitations of internal non-vital bleaching?

A

Doesn’t always work, but generally worth a go.

25
Q

What are the advantages to internal non-vital bleaching?

A
  • Easy
  • Conservative
  • Patient satisfaction
26
Q

What are the risks of internal non-vital bleaching?

A
  • External cervical resorption
  • Caused by diffusion of peroxide through dentine into periodontal tissues
27
Q

What is the technique for internal non-vital bleaching?

A
  • Record shade
  • Prophylaxis
  • Rubber dam
  • Remove filling
  • Remove GP from pulp chamber and 1mm below ACJ
  • Place 1mm RMGIC over GP to seal canal (prevents root resorption)
  • Remove very dark dentine
  • Etch internal surface
  • Place 10% carbamide gel
  • Cotton wool over this
  • Seal with GIC
  • Repeat at weekly intervals
28
Q

How often should internal non-vital bleaching be performed?

A

Every week until desired shade achieved. Normally takes 3-4 visits.

If no change after 4 visits, consider crown/veneer/composite build up.

29
Q

How often does non-vital bleaching need to be repeated?

A

Typically every 4-5 years, but this is variable.

30
Q

What can micro-abrasion be done with?

A

Acid (erosion) or pumice (abrasion).

31
Q

What are the indications for micro-abrasion?

A
  • Fluorosis
  • Orthodontic related demoralisation
  • Demoralisation with staining
  • Prior to veneering if dark staining is present
32
Q

What is the maximum legal limit of hydrogen peroxide release, in a bleaching agent?

A

6% is the maximum, any more than it is a criminal offence to apply it to a patient.

33
Q

Who can apply tooth bleaching to a patient?

A

Only those legally registered with the GDC to perform such treatment.

34
Q

What are the indications for internal non-vital bleaching?

A
  • Non-vital tooth
  • Adequate RCT
  • No apical pathology
35
Q

What are the advantages of chair-side vital external bleaching?

A
  • Controlled by professional
  • Can use heat and light
  • Quick results for patient

FINALS - Restorative Dentistry (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions