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Flashcards in Tooth Whitening Deck (57)
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1

List some extrinsic causes of tooth discolouration (5)

1. Smoking

2. Tannins
- Tea
- Coffee
- Red wine
- Guinness

3. Chromogenic bacteria
- Common in children

4. Chlorrhexidine

5. Iron supplements

2

List some intrinsic causes of tooth discolouration (7)

1. Fluorosis

2. Tetracycline

3. Non vitality
-Blood products
- Tooth dies becomes darker over time as pulp dies and products leach into dentine

4. Physiological
- Age changes

5. Dental materials
- Amalgam
- Root filling materials

6. Porphyria
- Red primary teeth

7. Cystic fibrosis
- Grey teeth

3

Whats the 1st method of tooth whitening for extrinsic staining?

HPT
- scaling etc

4

What are the 2 types of tooth bleaching?

1. External vital bleaching

2. Internal non-vital bleaching

5

When is external vital bleaching used? (2)

- Discolouration forms chemically stable, chromogenic products within the tooth surface

- Bleaching oxidises these compounds and leads to smaller molecules that are not pigmented

6

Active ingredient for vital external bleaching

Hydrogen peroxide
- Forms an acidic solution in water
- Breaks down to form water + o2
- Free radical per hydroxyl (HO2) is formed (the active oxidising agent)

7

What are the constituents of bleaching gel? (9)

1. Carbamide peroxide
2. Carbopol
3. Urea
4. Surfactant
5. Pigment dispersers
6. Preservative
7. Potassium nitrate
8. Calcium phosphate
9. Fluoride

8

What does carbamide peroxide break down to produce?

Hydrogen peroxide + urea

9

Function of carbopol (3)

1. Thickening agent

2. Slows the release of o2 and diffusion into enamel

3. Increases viscosity of gel so it stays where you put it
- Teeth
- Tray

10

Function of urea (2)

1. Raises pH

2. Stabilises Hydrogen peroxide
- Slows down the reaction

11

Function of surfactant

Allows gel to wet the tooth surface

12

Function of potassium nitrate/calcium phosphate

Desensitising agent

13

Function of fluoride

Prevents erosion
Desensitising agent

14

List factors that affect bleaching (4)

1. Time
More time = more effect

2. Cleanliness of tooth surface
Cleaner = better

3. Concentration of solution
Higher conc = more+quicker effect

4. Temperature
Higher = quicker effect

15

What must you check before starting bleaching?

Patient is dentally fit
Any leakage around carious cavity margins will lead to pulpal damage

- Take an initial shade
- Agree with patient + record in their notes
- Take a phoot with shade guide included in the picutre

16

Warnings for patient about external vital bleaching (6)

1. Sensitivity
2. Relapse
3. Restoration colour
4. Allergy
5. Might not work
6. Compliance with regime

17

What are the 2 types of vital external bleaching we can offer?

1. Chairside
2. Home bleaching

18

Advantages of in office bleaching (3)

1. Controlled by dentist
2. Can use heat/light
3. Quick results for patient

19

Disadvantages of in office bleaching (4)

1. Time for dentist
2. Can be uncomfortable
3. Results tend to wear off quicker
4. Expensive

20

Talk through the in-office bleaching technique (6)

1. Thorough cleaning of teeth

2. Ideally rubber dam, but atleast gingival mask

3. Apply bleaching gel to tooth

4. Apply heat/light

5. Wash/dry repeat

6. Takes 30 mins to an hour

21

Talk through the home vital bleaching technique (4)

1. 10-15% carbamide peroxide gel

2. Patient uses solution at home with a custom made mouthguard tray

3. Bleaches slowly, over several weeks

4. Easy for dentist + patient

22

What doest 16.7% carbamide peroxide equate to?

6% of hydrogen peroxide = max strength of solution

Anything stronger = illegal

23

How are mouth guards made? (4)

1. Alginate impressions of teeth

2. 0.5mm thick soft splint made

3. Should stop 1mm short of gingival margin

4. Buccal spacer to allow placement of gel

24

How long should a whitening tray be placed at home?

Atleast 2 hours
Preferably overnight

25

How quickly do patients see a result from tooth whitening

2-3 days

26

When should teeth be bleached? (4)

1. Age related darkening/discolouration
- Teeth with yellow/orange discolouration respond better than ones with bluish/grey discolouration

2. Mild fluorosis

3. Post smoking cessation
- Don't bleach smokers as its a waste of time

4. Tetracyclin staining
- Can work if prolonged tx
- Works better with yellow over grey
- Can take months

27

What are some issues revolving bleaching teeth? (5)

1. Sensitivity
2. Wears off
3. Cyotoxicity
4. Gingival irritation
5. Problems with bonding to tooth

28

How long does sensitivity take to resolve?

Resolves over 2-3 days post bleaching

29

What are some predictors of sensitivity (5)

1. Pre-existing sensitivity

2. High conc of bleaching agent

3. Frequency of change

4. Bleaching method

5. Gingival recession

30

Why does tooth whitening wear off? (2)

1. Oxidised chromogens gradually decrease with time
2. Retx 1-3yrs varies