Bleaching refers to the process of lightening the stains or colours inside enamel or dentine by using chemical agents.

A. Purpose

To whiten teeth and regain the normal colour of the teeth

B. Application

• Vital tooth
• Non-vital tooth treated by root canal therapy

C. Mechanism

Bleaching agents are used to oxidize the colour pigments in the discoloured teeth in order to whiten these teeth.

D. Material

Bleaching agents contain chemicals such as Carbamide Peroxide, Hydrogen Peroxide Hypochlorite, etc.

E. Procedures for bleaching

• Bleaching vital tooth
  Dentist will use different bleaching methods according to various oral conditions：
  • Impressions of teeth are taken to make a model. A custom whitening tray is constructed from this model. The trays are filled with a gentle whitening solution, and are inserted and worn over the teeth overnight. The patient should wear the tray every night according to the dentist's instructions and return to the dentist for follow-up appointments according to schedule.
  • In the dental clinic, the dentist will use a strong light to catalyse the highly concentrated bleaching agents to whiten teeth.

Treatment duration: 3 to 6 months

• Bleaching of non-vital tooth treated by root canal therapy
  • Endodontic treatment(Root canal therapy) of the tooth must be completed.
  • A cotton pellet with whitening agent is first placed inside the pulp chamber and the tooth is then filled.
  • Visit dentist periodically to check the progress of bleaching, and change the cotton pellet with whitening agent according to needs. The cotton pellet is removed after the bleaching process is finished and the tooth is then restored.
    Treatment duration: The treatment ends when the stains or colours are lightened, which takes approximately 1 - 3 months

F. Points to note before using bleaching agents

• Not all stains/colours could be removed.
• Improper use of bleaching agents will damage gums and tooth supporting tissues. Be careful when using bleaching agents and consult your dentist for proper usage of bleaching agents.
• Harmful to health if bleaching agent is ingested accidentally.

G. Points to note after bleaching

• Visit your dentist for check-up as advised.
• Bleaching can only keep the teeth white for a period of time. Repeated bleaching treatment is needed to keep the teeth white.