Whether you can still do all-ceramic dentures after four years of tooth extraction needs to be examined by your doctor to see the size of the remaining gap and the location of the missing tooth to determine. 1. The size of the remaining gap: due to the missing teeth for a long time, both sides of the teeth have been tilted or maxillary teeth have been elongated, resulting in the remaining gap is insufficient, can not be fixed bridge or implant denture all-ceramic crown restoration; if the gap is enough, or root canal treatment, orthodontics, etc. to make the gap between the missing teeth to return to normal, you can consider the all-ceramic dental restoration. 2. The location of the missing teeth: if the missing teeth for the free end of the missing teeth, that is, no teeth behind the missing teeth position, can not be fixed bridge all-ceramic dental restoration, but at this time you can consider all-ceramic dental implant denture repair. It is recommended to consult a doctor in time.