If the tooth becomes transparent, it is likely that the tooth has been decayed from the inside, which causes the dentin to be eroded and only the enamel remains. It is necessary to take dental film in time to judge, and if it is really caries, carry out filling treatment as soon as possible, because it often proves that the caries has reached a very deep level. Generally speaking, caries is not easy to be detected because the hole on the surface is small, but the bottom of it is big, and it looks like a small hole on the surface, but when it is really opened, it is found that the hole has been involved deeply. For the tooth that has involved the nerve, root canal treatment should be carried out in time to avoid the inflammation of the nerve.