My son bruised his tooth on a bad fall a couple of years ago. It has progressively become darker with time. It is a baby tooth, so I have never tried to whiten it since I know eventually he will lose it. The dentist feels the roots of his teeth are still quite far up, and it isn't likely he will lose it any time soon. The discoloration is bothering my son, though, and he tries to force it to feel wiggly. Therefore, I wondered if it is safe and worthwhile to use over the counter whitening products on a 5 year old child to whiten a bruised tooth.