I've had two fillings eight years ago. Recently, I noticed that they are staining/discoloring. When I
went to the dentist, he did some X-rays and he found some underneath the fillings. He said I need to get them replaced. One tooth may need a canal and a crown on because the decay is quite deep.
How do you get decay under the fillings? What can I do to prevent this from happening again with the new filling that I will be getting soon?
Please help! Thanks a lot!