Internal Bleaching

Question 1

What are 7 causes of internal tooth discoloration?

Answer 1

1. Pulp necrosis
2. Intrapulpal hemorrhage
3. Calcifica metamorphosis
4. Internal resorption
5. Age
6. Developmental defects
7. Systemic diseases

Question 2

Chemical, mechanical, or bacterial irritation of the pulp can cause what and what can this lead to?

Answer 2

Causes pulp necrosis. Tissue degradeation byproducts deposit in dentinal tubules typically discoloring the tooth to a grey color.

Question 3

What can result from an impact injury without pulpal necrosis but with an extensive formation of tertiary (irregular) dentin?

Answer 3

Calcific metamorphosis

Question 4

Calcific metamorphosis decreases the translucency of the tooth and results in what color discoloration?

Answer 4

Yellow/brown

Question 5

Is calcific metamorphosis quick or gradual over time?

Answer 5

Gradual

Question 6

What is an inflammatory condition resulting in progressive destruction of dentinal walls of canal caused by some form of canal wall injury (trauma, caries) and odontoclasts begin resportion?

Answer 6

Internal resorption

Question 7

What can bacteria do to the odontocalsts as they begin resorption?

Answer 7

Continue to stimulate internal resorption

Question 8

What is the pink tooth of mummery?

Answer 8

If internal resorption lesion is located coronally in the canal

Question 9

When will internal resorption resolve?

Answer 9

After RCT

Question 10

Is internal bleaching necessary on a tooth that has NSRCT for internal resorption?

Answer 10

No

Question 11

What are the factors of age that lead to tooth discoloration?

Answer 11

Extensive dentin formation (secondary dentin)
Thinning of enamel to expose dentin
Decreased translucency of enamel
Extrinsic discoloration due to food and beverages
Previous restorations, especially amalgam

Question 12

Ingestion of excessive amounts of fluoride during tooth formation will result in what appearance?

Answer 12

Chalky, white porous enamel that stains easily. Endemic fluorosis.

Question 13

Tetracycline in children and minocycline in adults can result in what type of internal discoloration?

Answer 13

Yellow, brown, dark grey

Question 14

What are 2 treatments for systemic drug staining?

Answer 14

1. External bleaching

2. Elective NSRCT and internal bleaching

Question 15

What systemic disease has a massive lysis of RBC’s leaving hemosiderin in tubules causing dark staining of primary teeth?

Answer 15

Erythroblastosis Fetalis

Question 16

Linear banding hypoplasia of several teeth is due to what?

Answer 16

High ever during tooth formation

Question 17

What is a genetic condition where heme is not made properly and the teeth have a red/brown discoloration?

Answer 17

Porphyria

Question 18

What is a genetic disorder causing abnormal form of hemoglobin, causing destruction of red blood cells leading to anemia (causes blue/brown/green discoloration)?

Answer 18

Thalassemia

Question 19

What is a genetic disorder causing red blood cells to form a sickle-shape, delivering less oxygen to the body, and are easily trapped in veins (causes blue/brown/green discoloration)?

Answer 19

Sickle Cell anemia

Question 20

What is a tooth development disorder with the teeth covered with a thin, abnormally formed enamel (causes yellow/brown discoloration)?

Answer 20

Amelogenesis imperfecta

Question 21

Are erythroblastosis fetalis, high fever during tooth formation, porphyria, thalassemia, sickle cell anemia, amelogenesis imperfecta, dentinogenesis imperfecta amenable to bleaching?

Answer 21

No

Question 22

What can be cause by obturation material leading to a dark discoloration?

Answer 22

Endodontic iatrogenic discoloration

Question 23

What is the most common iatrogenic etiology related to tooth discoloration?

Answer 23

Endodontic iatrogenic discoloration

Question 24

What can make endodontic iatrogenic discoloration hard to bleach?

Answer 24

Metallic sealer (Zinc Oxide Eugenol)

Question 25

What will endodontic iatrogenic discoloration require, and is it expected to completely resolve?

Answer 25

Requires internal bleaching and complete resolution may not occur?

Question 26

How can endodontic iatrogenic discoloration be avoided?

Answer 26

Remove gutta percha to below gingival margin/CEJ

Question 27

Beyond obturation materials, what is another cause of endodontic iatrogenic discoloration?

Answer 27

Remnants of pulpal tissue

Question 28

What are 2 other sources of discoloration provided by the dentist?

Answer 28

1. Intracanal medicaments | 2. Coronal restorations

Question 29

What do we use as our bleaching materials?

Answer 29

1. Hydrogen peroxide | 2. Sodium perborate

Question 30

Is hydrogen peroxide (Superoxyl), which is 30% hydrogen peroxide, used along for internal bleaching?

Answer 30

No. Acidic pH will increase the risk of external cervical root resorption.

Question 31

What is another concern with 30% hydrogen peroxide?

Answer 31

Caustic to tissue

Question 32

What is the material of choice for internal bleaching that comes as a dry powder and can be mixed with hydrogen?

Answer 32

Sodium perborate

Question 33

Is sodium perborate safer than hydrogen peroxide?

Answer 33

Yes, it has an alkaline pH

Question 34

What is the most commonly used material for external bleaching?

Answer 34

3-15% solutions of Carbamide peroxide

Question 35

What are 3 indications for internal bleaching?

Answer 35

1. Discoloration of pulp chamber origin 2. Dentin discoloration 3. Discoloration that is not amenable to external bleaching

Question 36

What are 5 contraindications to internal bleaching?

Answer 36

1. Superficial enamel discoloration 2. Defective enamel formation 3. Severe dentin loss 4. Presence of caries 5. Discolored proximal composites

Question 37

What are 2 complications associated with internal bleaching?

Answer 37

1. External root resorption | 2. Chemical burns

Question 38

The external root resorption risk is increased by what 2 factors?

Answer 38

30% hydrogen peroxide | Heat

Question 39

How does external root resorption occur during internal bleaching?

Answer 39

Bleach materials diffuse through dentinal tubules and cementum defects into PDL causing an acidic environment leading to an inflammation response

Question 40

What blocks dentinal tubules from penetration by bleaching agent to decrease risk of external root resorption?

Answer 40

2mm seal of glass ionomer or composite resin above the CEJ

Question 41

The thermocatalytic bleaching technique does what to the hydrogen peroxide and increase what?

Answer 41

Creates hydroxyl radicals and increased diffusion of hydrogen peroxide to the root surface causing damage to the cementum and PDL leading to external cervical resorption.

Question 42

What technique is recommended for all internal bleaching?

Answer 42

Walking bleach technique

Question 43

What is the mix for the walking bleach technique?

Answer 43

Hydrogen peroxide 30% and sodium perborate mixed to sand-in-water consistency

Question 44

What is the recall schedule for walking bleach technique?

Answer 44

Patient returns every 7 days to replace bleaching material and check progress