It is not necessary to have an implant for every tooth that is being replaced. The number of implants necessary to provide support depends on the type of implants used and the type of teeth (removable vs. non- removable) that will be attached to the implants. A thorough oral exam and panoramic x-ray is all that is necessary in most cases, to determine which implant can be used and how many must be used. Sometimes additional x-rays or CT scans are used in more complicated cases.