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All-on-4 vs All-on-6: What's the Difference?

Dr. Nav Atwal

All-on-4 supports a full arch on four implants, while All-on-6 uses six. The extra two implants in All-on-6 spread chewing forces more widely, can better support heavier zirconia bridges, and add backup if one implant has trouble — but they require more bone and cost more. All-on-4 is often ideal where bone is limited, using angled implants to avoid grafting. Neither is universally better; the right choice depends on bone volume, bite force, the arch treated, and the prosthesis material.

Key Takeaways

- All-on-4 uses four implants per arch; All-on-6 uses six. - All-on-6 spreads chewing load more widely and offers more backup if an implant has trouble. - All-on-4 is often ideal for limited bone, using angled implants to avoid grafting. - All-on-6 usually costs more and can better support heavier zirconia bridges or stronger bites. - Neither is universally better — the right choice depends on bone, bite, the arch treated, and materials.

All-on-4 and All-on-6 are the two most common forms of All-on-X, and the difference is exactly what the names suggest: the number of implants used to support a full arch of fixed teeth. Both can deliver an excellent, permanent result — the question is which is right for a particular jaw, bite, and set of goals.

The Core Difference

All-on-4 supports the entire arch on four implants, typically two placed vertically at the front and two angled at the back to maximize contact with available bone. All-on-6 adds two more implants, distributing the load across six points instead of four.

Support and Load Distribution

More implants spread chewing forces more widely. All-on-6 can therefore offer greater support for heavier prostheses — such as full zirconia bridges — and for patients with strong bites or a history of grinding. All-on-4, when well planned, is biomechanically sound and highly successful, but it concentrates the load on fewer points.

Bone Requirements

All-on-4 was specifically designed to work where bone is limited, using angled posterior implants to reach denser bone and often avoid the need for grafting. All-on-6 requires more available bone to place the additional implants, which can mean grafting in deficient areas.

Redundancy

With six implants, the arch has more built-in backup: if one implant were to develop a problem, the remaining implants can often continue to support the prosthesis. With four, each implant carries more responsibility.

Cost

Two extra implants mean more surgical time and materials, so All-on-6 generally costs more than All-on-4. The right choice balances that against the clinical benefit in your specific case.

Upper vs Lower Jaw

The upper jaw tends to have softer bone than the lower, so some clinicians favor additional implants in the upper arch for extra support. The lower jaw's denser bone often supports an All-on-4 design very predictably. This is a case-by-case judgment.

So, Which Is Better?

Neither is universally superior. More implants are not automatically better — a well-planned All-on-4 can outperform a poorly planned All-on-6. The decision depends on your bone volume, bite force, which arch is being treated, the material of the final teeth, and your budget.

In my practice, that decision follows a CBCT scan and a full assessment of bone and bite, so the number of implants reflects what your case actually requires — not a one-size-fits-all formula. A consultation is the way to find your answer.

— Dr. Nav Atwal

Frequently Asked Questions

What is the difference between All-on-4 and All-on-6? The difference is the number of implants supporting the arch: All-on-4 uses four implants, while All-on-6 uses six. More implants spread chewing forces more widely. Is All-on-6 better than All-on-4? Not universally. All-on-6 offers more support and redundancy but needs more bone and costs more, while a well-planned All-on-4 is highly successful. The best choice depends on your case. Does All-on-6 cost more than All-on-4? Yes. The two additional implants require more surgical time and materials, so All-on-6 generally costs more. Do you need bone grafting for All-on-4? Often not. All-on-4 was designed to use angled implants that reach available bone, which frequently avoids the need for grafting. All-on-6 may require more bone. Is more implants always better for full-arch treatment? No. More implants are not automatically better; a well-planned four-implant case can outperform a poorly planned six-implant one. Planning quality matters most. Which is better for the upper jaw? The upper jaw has softer bone, so additional implants are sometimes preferred there for extra support, but this is decided case by case after a scan.

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