All-on-4 vs All-on-6

Quick answer

The difference is how many implants carry the arch — four or six — and the choice is driven by available bone, bite forces and the planned prosthesis, not by one being a better protocol. We found no systematic review comparing their outcomes directly, so anyone telling you one is definitively superior is going beyond the evidence.

We do not yet hold enough verified data on both sides to build a meaningful comparison table.

The biggest differences

All-on-4 places four implants, angling the rear two so they reach further back along the jaw without entering the sinus or the nerve canal — which is precisely what lets it avoid grafting in many cases. All-on-6 adds two more fixtures, spreading load across a longer span. More implants is not automatically better: each one needs enough bone to sit in, and placing six where there is comfortable room for four is not a free improvement.

Clinical evidence

This is where we have to be careful. All-on-4 has a body of literature behind it, including a systematic review of the protocol itself. What we could not find was a systematic review comparing All-on-4 against All-on-6 head to head — what exists is largely finite-element modelling and individual trials. We have therefore recorded the comparative outcome as insufficient evidence rather than reporting a winner from weaker sources.

Cost considerations

All-on-6 generally costs more, because two additional fixtures and their components are involved. That difference is not itself a reason to choose one over the other in either direction — a cheaper plan that does not suit the bone is not a saving, and a more expensive one is not automatically more robust.

What may influence clinical selection

The factors that actually decide this are the volume and quality of bone in each region of the jaw, whether the opposing arch is natural teeth or a denture, whether the patient grinds, and what the final prosthesis is made of. It is a planning decision made from a CT scan by the clinician who will carry out the work, not something determinable from a website.

Important limitations

'All-on-4' is a Nobel Biocare trademark, listed on its own trademarks page as the 'All-on-4 treatment concept'. In practice the phrase is used generically for any four-implant full-arch protocol, so a quote bearing the name does not by itself tell you which implant system or components will be used. That is worth asking about explicitly.

So which is better?

Neither is universally better, and any page telling you otherwise is selling something. These are different designs with different trade-offs, and the right choice depends on the bone available, the position in the mouth, the planned restoration, and what the treating clinician is equipped and experienced to place and to service years from now. That last point is easy to overlook and matters more than most specification differences: components need to remain obtainable for as long as the implant is in place.

Sources

Numbers match the citations beside each claim above.

Primary sources

[1]Trademarks — Nobel Biocare — Nobel Biocare Services AG. Accessed 2026-07-21.

Clinical evidence

[2]The all-on-four treatment concept: Systematic review — Journal of Clinical and Experimental Dentistry (PMC), 2017. Accessed 2026-07-21.
[3]Loading Protocols for Fixed Prostheses in Edentulous Jaws — ITI Consensus Statement — International Team for Implantology (ITI), 2013. Accessed 2026-07-21.