- The "walking bleach" technique is primarily used to treat non-vital (root canal-treated) teeth.
- This method is an internal bleaching procedure aimed at whitening discolored teeth that have undergone root canal treatment.

- When a tooth becomes non-vital, it often loses its natural color due to the breakdown of blood products and remnants of pulp tissue inside the tooth.
- External bleaching methods are usually ineffective in these cases because the discoloration originates from within the tooth structure rather than on the surface.

- The walking bleach technique involves placing a bleaching agent, commonly hydrogen peroxide or carbamide peroxide, inside the pulp chamber of the non-vital tooth.
- The bleaching agent is sealed within the tooth and left to act over several days, allowing it to penetrate the dentin and oxidize the chromogens causing discoloration.
- This procedure is repeated if necessary until the desired shade is achieved.

This technique is NOT suitable for teeth with:
- Early enamel caries because the discoloration is not internal and requires restorative treatment.
- Periodontally compromised teeth where the primary issue is supporting tissues, not tooth discoloration.
- Teeth with reversible pulpitis where the pulp is still vital and bleaching is contraindicated as it may cause further pulp damage.

In summary, the walking bleach technique is a conservative and effective approach specifically designed to whiten non-vital, root canal-treated teeth by applying a bleaching agent internally.

Reference: Grossman’s Endodontic Practice, 13th Edition, Chapter 22: Internal Bleaching of Discolored Teeth, Page 1010