The prognosis for internal bleaching is best if the etiology of the stain is:

 # The prognosis for internal bleaching is best if the etiology of the stain is:

A. Amalgam restorations

B. Necrotic pulp tissue

C. Precipitation of metallic salts

D. Silver containing root canal sealers

The correct answer is B. Necrotic pulp tissue.

Internal bleaching treatments are most effective among root canal treated teeth which have internal stains or discoloration due to blood, necrotic tissues and fluids that could have leaked in prior to root canal therapy.

Internal tooth bleaching is done by placing peroxide directly into the pulp chamber of a root canal treated tooth. The peroxide will then directly work on the stains within the tooth structure.

Staining from the silver containing root canal sealers and from mercury of amalgam restorations appear very dark. These stains are seldom treated by bleaching. Restorative treatments provide the most esthetic result because they remove or cover up these stains. 

CLICK HERE FOR MORE MCQs