In the All on 4 system the entire dental restoration is supported by four implants, while in the all on 6 six implants are placed, providing more stable support and better distribution of chewing forces.
It is not advisable to place a zirconia All on 4 because four implants are not sufficient support for such a heavy prosthetic construction.
For a zirconia prosthetic restoration at least anAall on 6, meaning six implants, is required.
All on 4 is suitable when making an acrylic prosthetic restoration because this is a much lighter material that can be safely supported by four implants.
The final decision is always made after a detailed analysis of the bone and the individual needs of the patient, in order to achieve a long lasting and functional result.
It is particularly important for patients to know whether a zirconia All on 4 or All on 6 is being made as monolithic crowns or as zirconia layered with ceramic.
Since a prosthetic restoration made entirely of zirconia cannot meet aesthetic requirements to the same extent as a zirconia ceramic prosthetic restoration, it is crucial that patients are informed in advance about which type of prosthetic work will be placed.