Internal Bleaching Flashcards
What are 7 causes of internal tooth discoloration?
- Pulp necrosis
- Intrapulpal hemorrhage
- Calcifica metamorphosis
- Internal resorption
- Age
- Developmental defects
- Systemic diseases
Chemical, mechanical, or bacterial irritation of the pulp can cause what and what can this lead to?
Causes pulp necrosis. Tissue degradeation byproducts deposit in dentinal tubules typically discoloring the tooth to a grey color.
What can result from an impact injury without pulpal necrosis but with an extensive formation of tertiary (irregular) dentin?
Calcific metamorphosis
Calcific metamorphosis decreases the translucency of the tooth and results in what color discoloration?
Yellow/brown
Is calcific metamorphosis quick or gradual over time?
Gradual
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?
Internal resorption
What can bacteria do to the odontocalsts as they begin resorption?
Continue to stimulate internal resorption
What is the pink tooth of mummery?
If internal resorption lesion is located coronally in the canal
When will internal resorption resolve?
After RCT
Is internal bleaching necessary on a tooth that has NSRCT for internal resorption?
No
What are the factors of age that lead to tooth discoloration?
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
Ingestion of excessive amounts of fluoride during tooth formation will result in what appearance?
Chalky, white porous enamel that stains easily. Endemic fluorosis.
Tetracycline in children and minocycline in adults can result in what type of internal discoloration?
Yellow, brown, dark grey
What are 2 treatments for systemic drug staining?
- External bleaching
2. Elective NSRCT and internal bleaching
What systemic disease has a massive lysis of RBC’s leaving hemosiderin in tubules causing dark staining of primary teeth?
Erythroblastosis Fetalis
Linear banding hypoplasia of several teeth is due to what?
High ever during tooth formation
What is a genetic condition where heme is not made properly and the teeth have a red/brown discoloration?
Porphyria
What is a genetic disorder causing abnormal form of hemoglobin, causing destruction of red blood cells leading to anemia (causes blue/brown/green discoloration)?
Thalassemia
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)?
Sickle Cell anemia
What is a tooth development disorder with the teeth covered with a thin, abnormally formed enamel (causes yellow/brown discoloration)?
Amelogenesis imperfecta
Are erythroblastosis fetalis, high fever during tooth formation, porphyria, thalassemia, sickle cell anemia, amelogenesis imperfecta, dentinogenesis imperfecta amenable to bleaching?
No
What can be cause by obturation material leading to a dark discoloration?
Endodontic iatrogenic discoloration
What is the most common iatrogenic etiology related to tooth discoloration?
Endodontic iatrogenic discoloration
What can make endodontic iatrogenic discoloration hard to bleach?
Metallic sealer (Zinc Oxide Eugenol)
What will endodontic iatrogenic discoloration require, and is it expected to completely resolve?
Requires internal bleaching and complete resolution may not occur?
How can endodontic iatrogenic discoloration be avoided?
Remove gutta percha to below gingival margin/CEJ
Beyond obturation materials, what is another cause of endodontic iatrogenic discoloration?
Remnants of pulpal tissue
What are 2 other sources of discoloration provided by the dentist?
- Intracanal medicaments
2. Coronal restorations
What do we use as our bleaching materials?
- Hydrogen peroxide
2. Sodium perborate
Is hydrogen peroxide (Superoxyl), which is 30% hydrogen peroxide, used along for internal bleaching?
No. Acidic pH will increase the risk of external cervical root resorption.
What is another concern with 30% hydrogen peroxide?
Caustic to tissue
What is the material of choice for internal bleaching that comes as a dry powder and can be mixed with hydrogen?
Sodium perborate
Is sodium perborate safer than hydrogen peroxide?
Yes, it has an alkaline pH
What is the most commonly used material for external bleaching?
3-15% solutions of Carbamide peroxide
What are 3 indications for internal bleaching?
- Discoloration of pulp chamber origin
- Dentin discoloration
- Discoloration that is not amenable to external bleaching
What are 5 contraindications to internal bleaching?
- Superficial enamel discoloration
- Defective enamel formation
- Severe dentin loss
- Presence of caries
- Discolored proximal composites
What are 2 complications associated with internal bleaching?
- External root resorption
2. Chemical burns
The external root resorption risk is increased by what 2 factors?
30% hydrogen peroxide
Heat
How does external root resorption occur during internal bleaching?
Bleach materials diffuse through dentinal tubules and cementum defects into PDL causing an acidic environment leading to an inflammation response
What blocks dentinal tubules from penetration by bleaching agent to decrease risk of external root resorption?
2mm seal of glass ionomer or composite resin above the CEJ
The thermocatalytic bleaching technique does what to the hydrogen peroxide and increase what?
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.
What technique is recommended for all internal bleaching?
Walking bleach technique
What is the mix for the walking bleach technique?
Hydrogen peroxide 30% and sodium perborate mixed to sand-in-water consistency
What is the recall schedule for walking bleach technique?
Patient returns every 7 days to replace bleaching material and check progress
