Implants are titanium screws that can be used for many applications.
Single tooth. An implant can be place in the bone to support a single crown. This is typically the preferred option to replace a single missing tooth. The alternative is a dental bridge that requires cutting down the adjacent teeth. Single teeth sites are typically straightforward procedures but are more complex if there is missing bone or if they are for aesthetic front teeth where bone or soft tissue grafts may be needed.
Multiple teeth. In situations where multiple teeth are lost or a previous dental bridge has failed then implants can provide a “fixed bridge” non-removable solution. The alternative is a long span bridge on adjacent teeth or a removable partial denture. In some cases multi sites are done to provide fixed teeth to a fully endentulous arch.
partial edentulous and full endentulous multi-site implant prosthesis
Replacing dentures. If you have full dentures or a partial denture and you want to “get rid of the denture” then multiple implants can be used to achieve a fixed solution. In the case where a full arch of teeth is missing implants can provide a “fixed” non removable denture bolted in place with a little as 4 implants. For tooth like restoration implants can support a series of fixed bridges that are more like dental bridges but on implants instead of teeth.
Supporting dentures. If you are “ok” wearing a denture but want a more stable denture, then implants can be used to assist with retention. As little as 2 implants with a snap-on connector can provide cost effective support for a lower denture. For more stability and also for the upper arch 4 implants are usually used and connected to a bar to lock the denture in place.