Implants are titanium cylinders which are placed into the bone of the jaw, which secure over time via a process known as osseointegration, wherein the bone grows back tightly around the implant – This is a process very similar to that which happens when a broken bone heals. In the case of a broken bone, the limb is supported by a plaster cast to stop the two ends of the bone moving. The equivalent of this with dental implants is the screw thread, which stabilises the implant in the bone. Except under certain circumstances, it is generally safer not to put any load on the implant until the bone has attached, usually within 6 to 8 weeks. Once osseointegration has occurred, then the implant is extremely well connected into the bone and is ergo stable.
During the healing period, a small cap is screwed into the implant, which is either flush or buried beneath the gum. It is usually possible to have a temporary tooth in the interim, although in the case of existing dentures these may need to be left out for a short period.
The cap is then removed and impressions taken to make the permanent teeth. A post-like component called an abutment is screwed into the implant.
A crown is then made to fit on the abutment which is usually cemented into place, but can also be held in by a screw.
If more than one implant is placed, these can be used to support multiple teeth in the form of a bridge.
Alternatively, implants can be placed and then dentures secured to them by means of a press stud type arrangement. Whilst not as secure as fixed teeth, this represents a huge increase in stability compared to conventional dentures.