All-on-4 and All-on-6 are types of fixed dental prostheses that use a certain number of dental implants to support the prosthesis in the upper or lower jaw.
All-on-4 involves placement of four implants in either the upper or lower jaw, while All-on-6 involves placement of six implants, with the extra two providing additional support for a more secure fit. In both cases, the aim is to replace missing teeth with a fixed prosthesis that is supported by the implants.