Tooth Whitening

Question 1

List 3 types of extrinsic staining:

Answer 1

1. Beverages e.g. tea or coffee
2. Tobacco
3. Mouthwashes e.g. chlorhexidine

Question 2

List 3 potential extrinsic stain-removal options:

Answer 2

1. Prophy paste
2. Ultrasonic
3. Airflow

Question 3

List 4 types of intrinsic staining:

What is unique about these types of staining?

Answer 3

1. Amelogenesis imperfecta
2. Dentinogenesis imperfecta
3. Enamel hypoplasia
4. Root resorption

These are all resistant to whitening/bleaching

Question 4

What are 2 common bleaching materials used?

Which of the 2 materials is more stable and why?

Answer 4

1. Hydrogen peroxide H2O2
2. Carbamide peroxide -more stable because it releases 1/3 of concentration compared to HP

Question 5

How quickly does the bleach pass from the enamel through to the pulp chamber?

Answer 5

5-15 minutes

Question 6

What is the most active free radical from hydrogen peroxide?

Answer 6

OH- 95%

Question 7

How do the oxygen molecules react with the teeth and stains?

Answer 7

They search for double carbon bonds, as they easily attach, which are the source of most colour stains in the tooth as they absorb light

Double carbon bonds are broken down into single carbon bonds which reflect light and make the teeth appear whiter

Question 8

What activation does chairside power bleaching use?

What negative effect can this technique have?

Answer 8

Light activation

Can cause more sensitivity and gingival irritation if not isolated correctly

Question 9

What % of carbamide and hydrogen peroxide are used for home whitening trays?

Answer 9

Overnight bleaching = 16% carbamide

Daytime bleaching = 6% hydrogen peroxide

Question 10

When is intracoronal bleaching used?

Answer 10

On non-vital single teeth

Question 11

What impact can ‘smokers’ paste have on the oral cavity?

Answer 11

Smokers paste is more abrasive so can thin the enamel and make teeth look darker

Question 12

What are 4 general harmful effects of bleaching?

Answer 12

1. Increased tooth sensitivity
2. Irritation of oral mucosa
3. Effects on enamel and dentine
4. Cervical erosion (internal bleaching)

Question 13

What are 3 effects bleaching has on enamel and dentine?

Answer 13

1. Demineralization of enamel
2. Increased enamel porosity
3. Reduced enamel and dentine microhardness

Question 14

Does whitening have any effect on composite, ceramic crowns, dentures etc.?

Answer 14

Whitening has no effect

Question 15

As of 2012, what is the maximum concentration of hydrogen peroxide permitted?

What is the minimum age for teeth whitening?

Answer 15

6%

18 years old