Internal tooth bleaching whitens teeth from the inside out. (It's also known as non-vital bleaching.) Usually, this teeth whitening procedure is done on a dead tooth thatâs previously had a root canal, an endodontic procedure that removes the soft inner core of dental pulp chamber.Â
After a root canal, a tooth can become discolored or develop intrinsic dark or yellow stains. Internal bleaching can remove discoloration from a dark tooth and restore its natural tooth color.Â
Because the bleach is left in the tooth for several days to weeks, the technique is often referred to as a âwalking bleach.â
This whitening technique can be very effective. âIâve seen amazing results from internal bleaching following root canal treatment,â says Dr. Steven Davidowitz, a leading cosmetic dentist in New York City.
In one study where internal bleaching was done on 255 teeth in 203 patients, researchers reported that all teeth had either âgoodâ or âacceptableâ color change, and there were no cases that were considered to have had no change at all. All of the gray cases and almost all the light yellow and black cases had âgoodâ outcomes. The dark yellow teeth were harder to bleach, and about oneâthird of this group had only âacceptableâ changes rather than âgoodâ changes. However, overall, the results of the bleaching were very encouraging and predictable.
The procedure can also be redone, if sufficient whitening doesnât occur the first time.Â