In the back of the mouth where bite forces are extremely strong, one implant per tooth is the ideal.
Although not always required, alternatively, if multiple teeth are missing within the same region, several missing teeth can also be replaced with fewer implants because dental implants are stronger than the natural tooth roots. This solution includes having implant fixed bridges done.
If you are missing several teeth then an implant supported bridge can replace them in function, form and esthetics. An implant fixed bridge is very much like a conventional bridge except the support is actually over implants rather than natural teeth.Natural biting capacity