Bleaching

Question 1

What is bleaching?

Answer 1

The lightening of the color of a tooth through the application of a chemical agent to oxidize the organic pigmentation in the tooth.

Question 2

whitening techniques may be used

Answer 2

(tooth whitening) or
(tooth bleaching)

Question 3

vital tooth whitening can be done in

Answer 3

the dental office by the dental team or at home(nightguard vital whitening)

Question 4

Teeth discoloration Classified into 4 categories

Answer 4

1. Extrinsic stain.
2. Intrinsic stain.
3. Defect on the enamel or dentin (environmental,
   hereditary)
4. Other factors.

Question 5

Whitening agents

Answer 5

 Hydrogen peroxide (H2O2): is a strong oxidizing agent , releases free
radicals of oxygen that react with pigments in both extrinsic and intrinsic

 carbamide Peroxide (CH6N2O3): is a complex of two molecules, urea and hydrogen peroxide.

 Sodium Perborate: is another
weak oxidizing agent on non vital teeth

Question 6

Bleaching techniques

Answer 6

Vital - at home > night guard
In office > professionally applied

Non vital - in office > internal / external
*tooth endodontic treatment must be
completed.

Question 7

Walking whitening (internal)

Answer 7

After the pulp chamber is cleaned, the gutta-percha is removed 2 mm below the cemento-enamel junction, resin modified ionomer over gutta percha and the bleaching agent is applied .
 Sodium perborate mixed with 35% hydrogen peroxide
or 10% carbamide Peroxide is applied internally to the pulp chamber.
 The canal is packed with a cotton pellet and sealed with
zinc phosphate. ( Usually requires 2-3 visits ) .

Question 8

Walking whitening (internal) advantages

Answer 8

 No ingestion of gel.
 Patient didn’t complain of sensitivity after internal bleaching

Question 9

Walking whitening (internal) disadvantages

Answer 9

 Multiple patients visit ,once a week for 4 weeks .
 Need to open the orifice and replace the bleaching materials .

Question 10

Power whitening (external)

Answer 10

 The canal is sealed and the tooth is isolated with a resin.
 An in-office heat , light or laser activated
bleaching material may be applied to the
coronal surface of the tooth

Question 11

Professionally Applied, In-Office Whitening

Answer 11

 Hydrogen peroxide solution placed directly on the teeth (delivered by syringe) , avoid damage to the vital pulp.

Question 12

Professionally Applied, In-Office Whitening advantages and disadvantages

Answer 12

ADVANTAGES:
● Achieve a fast results.
DISADVANTAGES :
● if the soft tissues is not protected well it will be injured
● Greater sensitivity.
● may require more than one visit to achieve

Question 13

Patient-Applied ,
Professionally Supervised Whitening:

Answer 13

Either hydrogen peroxide or carbamide peroxide may be used in the patient- applied, professionally supervised technique.

Hydrogen peroxide :
 Average number of treatments Once per day for 2-3 hours
 Takes about 3-4 weeks for measurable results to be seen.

Question 14

Carbamide peroxide

Answer 14

The trays are worn during the day for multiple treatment sessions of 2 to 4 hours

Question 15

Carbamide peroxide contraindications

Answer 15

1. Children with large pulp or teeth with cracks .
2. Exposed root surfaces and severe loss of enamel .
3. In the pregnant woman ,or patient with an allergy to the ingredient in the carbamide peroxide .
4. Inability to tolerate taste (at-home bleaching) or technique (in-office) .
5. Patient with hypersensitivity .

Question 16

Carbamide peroxide advantages and disadvantages

Answer 16

Advantages
. The fee is low in comparison with the other esthetic restoration.
. No teeth preparation is required.

Disadvantages :
. Patients may report dentine hypersensitivity.
. Patient required a multiple visits.
. The outcome and prognosis are unpredictable.
. Bleaching procedure using peroxides will produce free radicals. Free radicals have been linked with cancer
. gingival irritation
. Tooth sensitivity