Internal, or non-vital, bleaching is used to lighten a darkly discoloured tooth that has had root canal therapy. A chemical oxidizing agent is placed within the coronal portion of a tooth to remove tooth discoloration. It may be performed in the dental office using a procedure known as "chair side bleach." In this procedure, bleach crystals are placed inside the tooth, left for a period of time, and then removed before leaving the office. This may be done once or several times, depending upon the discoloration of the tooth. Another method is known as "walking bleach". In this procedure, bleach crystals are placed inside the tooth, left for several days and then the patient returns to the dental office to have the bleach crystals removed. Again, this procedure may be performed one or more times, depending upon the discoloration of the tooth.

before non-vital bleaching	after non-vital bleaching