Discoloration of teeth م3 Discoloration of teeth Intrinsic discoloration Extrinsic discoloration

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 hygiene ingestion of chromatogenic foods and drinks tobacco use.

“located within the tooth and are accessible only by bleaching.” Intrinsic stains “located within the tooth and are accessible only by bleaching.” Intrinsic color changes may be caused by : aging ingestion of chromatogenic foods and drink tobacco usage microcracks in the enamel tetracycline medication excessive fluoride ingestion severe jaundice in infancy dental caries restorations

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

Vital Bleaching Advantages 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.

hydroxyl radical Carbamide peroxide Hydrogen peroxide DOUBLE BONDS UREA Hydrogen 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  When the discoloration is from within the pulp chamber, from necrotic pulp tissue or from staining agents that are present in the pulp chamber, the bleaching treatment need to take place within the pulp chamber

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

Recommendations Sodium perborate mixed with water OR 10% carbamide peroxide

Potential Results Before After

Alternatives to bleaching Microabrasion Veneers (Direct and Indirect) Crowns