bleaching

Discoloration of teeth

Intrinsic discoloration Extrinsic discoloration
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Extrinsic stains

“located on the surface of the tooth and are most easily removed by external cleaning.”Extrinsic color changes may be due to: poor oral hygieneingestion of chromatogenic foods and drinkstobacco use.

Intrinsic stains

“located within the tooth and are accessible only by bleaching.”Intrinsic color changes may be caused by :agingingestion of chromatogenic foods and drink tobacco usagemicrocracks in the enameltetracycline medicationexcessive fluoride ingestionsevere jaundice in infancydental cariesrestorations

VITAL BLEACHING

Commonly known as, tooth whitening is a noninvasive method of lightening dark or discolored teeth.

Vital BleachingAdvantages

Low cost High success rate No tooth alteration

Vital Bleaching Disadvantages

Unpredictable results Need Re-treatment Possible side effects Transient sensitivity

Dental bleaching agents

Composition Carbamide peroxide 5% to 40% Carbopol ( slow oxygen releasing) Glycerin (thickening agent) Sodium hydroxide Flavors and fluoride

Mode of action

In saliva Carbamide peroxide converts to hydrogen peroxide, the active bleaching agent, and urea. Hydrogen peroxide, typically generates short-lived oxygen intermediates, such as hydroxyl radical It enters enamel or dentine and diffuse to areas of discoloration and breaks down some of the double bonds in discolored or stained compounds, results in whitened appearance.

Hydrogen peroxide

UREA
Carbamide peroxide
hydroxyl radical
DOUBLE BONDS

Bleaching Techniques

In-office bleaching technique Laser bleaching Dentist-prescribed, home applied bleaching Non vital bleaching

In-office Bleaching(Clinical Protocol)

Clean teeth with pumice Record pre-op shade Isolate teeth as close to the gingival margin as possible with rubber dam


Mix the thickening agent with 35% hydrogen peroxide . Place the gel material on the teeth for 30 min

Rinse and clean; remove rubber dam and record post-op shade

Laser bleaching
Lasers are also used within the clinical setting for dental bleaching. Quick results expensive

Recommended agents for bleaching

35% hydrogen peroxide for in office bleaching 10% carbamide peroxide for home bleaching

Contraindications of bleaching

Discoloration due to restorations Children with large pulp horns and cracks exposed roots and severe enamel loss

Non vital bleaching

Techniques for non vital bleaching
Thermocatalytic technique Walking bleaching Inside-outside bleaching

Recommendations

Sodium perborate mixed with water OR 10% carbamide peroxide

Potential Results

Alternatives to bleaching
Microabrasion Veneers (Direct and Indirect) Crowns