Internal tooth whitening is a method of whitening a tooth from the inside out and therefore requires access inside the tooth.
This type of whitening is complete when a particular tooth is darkened or discolored. This usually occurs when the nerve inside the tooth has died due to either infection or trauma.
Although there may be a lot of different reasons for a tooth to be darker than the rest, the most common reason is internal discolouration or pulp problems.
No anaesthetic or needles are required for this procedure because the nerve has already been removed from the tooth, therefore the tooth has no feeling in it.