ENDO Bleaching

Question 1

What are the types of tooth discolouration?

Answer 1

Intrinsic Extrinsic

Question 2

What is intrinsic staining?

Answer 2

Staining that involves the dentine

Question 3

What is extrinsic staining?

Answer 3

Staining that involvesthe enamel

Question 4

Describe intrinsic staining?

Answer 4

Staining of the detine from:
Pulpal changes
Iatrogneic
Others (genetic/tetracycline)

Question 5

Describe extrinsic staining?

Answer 5

Staining of the dental pellicle, caused by smoking, wine, coffee/tea or can be flurosis

Question 6

What pulpal changes can cause instrinsic staining?

Answer 6

Canal calcification, pulp haemorrhage or necrosis

Question 7

What iatrogenic changes can cause intrinsic staining?

Answer 7

• Failure to remove all pulp tissue remnants from pulp chamber
• Amalgam
• Certain sealer/cement in the pulp chamber (ledermix, GP)

Question 8

What are other causes of intrinsic staining?

Answer 8

Tetracycline staining, fluorosis, genetic (AI,DI)

Question 9

What is combined staining

Answer 9

Both intrinsic and extrinsic staining, caused by:
- Age
- Flurosis

Question 10

What are common bleaching materials used?

Answer 10

1. Sodium Perborate
2. Hydrogen Peroxide
3. Carbamide Peroxide

Question 11

What is the chemical formula for sodium perborate?

Answer 11

NaBO3

Question 12

What is the chemical formula for hydrogen peroxide?

Answer 12

H2O2

Question 13

What is the chemical formula for carbamide peroxide?

Answer 13

CH6N2O3

Question 14

What is the safest bleach material out of the 3?

Answer 14

Carbamide peroxide

Question 15

What is safer hydrogen peroxide or sodium perborate?

Answer 15

sodium perborate

Question 16

What is the pH of sodium perborate?

Answer 16

10

Question 17

What happens to sodium perborate when it comes into contact with water?

Answer 17

It reacts with water and breaks down into 10% hydrogen peroxide.

Question 18

Which bleaching material must you use rubber dam with?

Answer 18

Hydrogen peroxide

Question 19

What is the conc range of hydrogen peroxide and what is the most commonly used conc?

Answer 19

5-35%

30-35%

Question 20

How do you manage discoloured teeth.

Answer 20

1. Diagnose
2. Ask pt to change habits, remove staining foods from diet
3. Scale and clean
4. Bleaching
   - Home bleaching
   - In-chair bleaching
   - Microabrasion
5. Veneers

Question 21

What is the alternative to bleaching ?

Answer 21

Restorative treatments: veneers

Question 22

What are the disadvantages with restorative tx for discolored teeth?

Answer 22

Biologic cost
Tx only masks the discolouration

Question 23

How is home bleaching done?

Answer 23

In a custom tray or stick tray, with 10-30% carbamide peroxide

Question 24

How is power bleaching (in chair bleaching) done?

Answer 24

Using a high concentration 30-35% hydrogen peroxide, with the addition of light to enhance bleaching. More effective than home bleaching

Question 25

What is microabrasion?

Answer 25

Procedure to remove the superficial discoloured defects from teeth, and fluoride products are introducted to reminerlaise the teeth.

Question 26

What are the indications for microabrasion?

Answer 26

Mild flurosis

Question 27

what are the limitations of microabrasion?

Answer 27

Intrinsic discolourations like tetracycline staining, AI, DI

Question 28

What is the procedure of microabrasion?

Answer 28

Rubber dam, then apply PREMA paste (low conc H2O2 and fine grit) to the tooth surface, with prophy cup for 60s. Then give patient NaF gel to take home and apply. Recall in 4-6 weeks.

Question 29

What is the chemistry of bleach?

Answer 29

Bleaching teeth is an oxidation reduction reaction, hydrogen peroxide produces highly reactive free radicals, and they move through the dentine tubules to break down chromophores (organic material). This breakdown causes less light to be absorbed and thus the whitening effect.

Question 30

Can you restore teeth that have been bleached?

Answer 30

Only after 7 days, as it takes this long for the bleach to leech out of the tooth, otherwise it will affect the bond strength

Question 31

What is the walking bleach procedure?

Answer 31

Placing bleach in the access cavity of an endo treated tooth that has been intrinsically discoloured.

Question 32

What is the procedure for walking bleach technique?

Answer 32

1. Apply rubber dam 2. Access tooth 3. Acid etch the access cavity for 60s 4. Mix sodium perborate and water into a wet sand texutre 5. Deliver bleach to access cavity, esp labial wall of pulp chamber 6. Temporise: place cavit/GIC into the acces 7. Take post op photos 8. Recall in 7 days 9. Repeat process until desired bleaching effect acheived. 10. If happy, place definitive resto (make sure you wait atleast 7 days).

Question 33

Should you bleach the tooth immediately after obturation?

Answer 33

No, because the cavit and sealer will not have set.

Question 34

What is the recall for children compared to adults in the walking bleach procedure?

Answer 34

3-5 days in paeds pts compared to 7 days in adult pateints as the dentine tubules are wider and bleach will penetrate more.

Question 35

What discolouration will trauma usually cause?

Answer 35

Light yellow, grey

Question 36

What colour discolouration will prev dental tx, pulp necrosis, calcification cause?

Answer 36

Dark yellow