All-on-4 vs All-on-6 Dental Implants: The UK 2026 Decision

All-on-4 vs All-on-6 is the single biggest fork in the road for UK patients heading toward a full-arch dental implant. Both fit a fixed bridge on a whole jaw and both are done in reputable UK clinics every week. The difference is bone volume, budget and how the load is spread over the next twenty years.

TL;DR

All-on-4 vs All-on-6 comes down to bone volume, budget and long-term redundancy. All-on-4 uses four implants, including two angled at the back to avoid grafting, and is the fastest and most affordable full-arch route in the UK. All-on-6 uses six straight implants, spreads bite force more evenly and gives you more spare capacity if one implant ever fails. Survival at ten years for both is well above 90 per cent in published data. All-on-4 typically runs 12,000 to 18,000 pounds per arch privately, All-on-6 around 15,000 to 22,000. The right choice is the one your bone, your bite and your surgeon agree on.

All-on-4 vs All-on-6: the short answer

Both protocols replace a full arch of missing or failing teeth with a fixed bridge screwed onto implants, and both let you leave the clinic on the same day with a temporary set of teeth. The difference is the number and angle of the implants underneath.

All-on-4 uses four implants per arch, with the two rear implants tilted at around 30 to 45 degrees to catch dense bone at the front of the jaw and avoid the sinus or the nerve at the back. All-on-6 uses six implants, usually placed straight, spread more evenly across the arch. The extra two implants are the reason All-on-6 costs more, tolerates a broader range of bone anatomy and offers more mechanical margin over the life of the bridge.

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Neither is universally better. All-on-4 is the elegant answer when bone at the back is thin and grafting is not wanted. All-on-6 is better when there is more bone to work with, the bite is heavy, or the patient wants extra resilience.

Why the number of implants actually matters

The number of implants under a full-arch bridge decides three practical things: how the bite force is shared, how much can go wrong before the bridge is at risk, and how much bone can be worked with.

More implants share load across more anchor points. In a heavy bite, or in a bruxism patient, six well-placed implants spread the peak force more evenly than four, which reduces strain on each fixture and on the screws holding the bridge in place. Our guide on how a night guard protects an implant-supported bridge from clenching explains why mechanical load is often the hidden long-term risk.

More implants also give you redundancy. If a single implant is lost in year eight, an All-on-6 bridge can often be maintained on five while the failed fixture is replaced. On an All-on-4 bridge, that same loss is a bigger structural event and more often means remaking the whole bridge. That difference in resilience is the quiet reason many surgeons prefer six when the bone allows.

The All-on-4 protocol: how it works

All-on-4 was refined by Nobel Biocare and has become the reference protocol for restoring a full arch on a small number of implants. Two implants go in vertically at the front of the jaw, where the bone is naturally denser. Two more go in at the back, tilted at around 30 to 45 degrees, so the tip of each implant is anchored in solid bone in front of the sinus or the mental nerve.

The clever part is the angle. By tilting the rear implants, the surgeon lengthens the anchor and moves the biting point of the bridge further back, without needing to place implants in soft bone at the back of the jaw. That is why All-on-4 avoids sinus lifts and major grafting in most patients. A systematic review and meta-analysis on PubMed reported cumulative implant survival for the All-on-4 protocol at around 95 per cent at ten years, a strong long-term figure for such a limited number of implants.

A temporary fixed bridge is usually fitted on the same day, and the final bridge follows once the implants have integrated. Our overview of same-day dental implants and the honest UK timeline explains why same-day teeth are real but not the same as a finished restoration.

The All-on-6 protocol: what changes with two more implants

All-on-6 keeps the same principle, a fixed bridge over the whole arch, but adds two implants. In most cases all six implants are placed straight rather than tilted, distributed more evenly along the jaw. Some clinicians still tilt the rear implants on an All-on-6 arch when anatomy demands it, but the geometry is less extreme than in All-on-4.

The advantages are mechanical and biological. Six implants give a more even load distribution, which helps in heavy bites and bruxism cases. They also give more surface area for osseointegration, which is why the protocol is often preferred when bone quality is average rather than excellent. Our explainer on what osseointegration actually is sets out how living bone locks onto the implant surface over three to six months.

The trade-off is time and cost. Two more implants mean more surgery, more components and often a longer planning phase if grafting is needed. For the right patient, the extra investment buys real long-term margin. For a patient with limited bone at the back and no wish to graft, All-on-4 remains the more sensible answer.

Bone quality and quantity: the deciding factor

Bone is the first thing your surgeon assesses, and it often ends the debate. A cone beam CT scan measures the height, width and density of the bone in each part of your jaw and decides how many implants can be safely placed and where.

If your CBCT shows good bone right across the arch, both protocols are on the table. If the bone at the back of the upper jaw is thin because of a large sinus, or if the nerve at the back of the lower jaw sits high, All-on-4 is often the elegant answer because its angled rear implants can avoid those obstacles. If bone is generous at the back as well as the front, All-on-6 becomes attractive because you can place all implants straight and share the load evenly.

Where bone is inadequate for either protocol, grafting or a sinus lift can be planned, but it adds cost, healing time and complexity. Our practical guide to bone augmentation for dental implants in the UK explains the four main techniques and when each is used.

UK cost comparison: All-on-4 vs All-on-6 in 2026

The ranges below reflect what UK private clinics quote in 2026 for a full arch, including implants, abutments, the final fixed bridge and the same-day provisional teeth. NHS funding for full-arch implants is very restricted, as the NHS dental treatment cost guidance makes clear, so almost every full-arch case in the UK is a private one.

Option	Implants per arch	Typical UK price per arch (2026)	Grafting often needed
All-on-4	4	12,000 to 18,000 pounds	Rarely, by design
All-on-6	6	15,000 to 22,000 pounds	Sometimes, if bone is thin
Full mouth (both arches) All-on-4	8 total	22,000 to 32,000 pounds	Rarely
Full mouth (both arches) All-on-6	12 total	28,000 to 40,000 pounds	Sometimes

Prices vary by city, clinic tier, implant brand and bridge material. Titanium and acrylic bridges sit at the lower end, zirconia or hybrid porcelain push toward the top. Our line-by-line walkthrough in the full cost of All-on-4 broken down shows how the same quote can shift by thousands depending on materials, sedation and location. To compare like-for-like quotes from vetted UK clinics, use our free implant quote service.

Survival, complications and the long game

Both protocols perform well over the long term when placed by experienced clinicians and looked after properly. Published data for All-on-4 shows ten-year implant survival around 95 per cent, and All-on-6 studies report similar or slightly higher figures, with the extra implants offering additional mechanical margin rather than a dramatically different survival number.

The more useful long-term metric is what happens if something goes wrong. On an All-on-6 arch, losing one implant can often be managed by removing the failed fixture and continuing on the remaining five. On an All-on-4 arch, losing one of the four is a far more serious event and often means redesigning the entire bridge. That is why some UK surgeons quietly prefer All-on-6 for younger patients or heavy bite forces, even when All-on-4 would work.

The most common late complication for both protocols is peri-implantitis, an inflammatory process that damages the bone around the implant. It is largely preventable with good home care and regular hygiene visits, and our guide on spotting peri-implantitis early covers what to watch for. The British Dental Association also underscores that maintenance is as important as the surgery itself.

Who is the right candidate for each protocol

There is no perfect patient for either option, but there are clear patterns UK surgeons look for. All-on-4 tends to suit patients who want a fixed set of teeth, are ready to move on from failing teeth or ill-fitting dentures, and either do not have enough bone at the back for straight implants or would prefer to avoid grafting. It is often the protocol of choice for tighter budgets, because fewer implants keep costs down without compromising the fixed-bridge outcome.

All-on-6 tends to suit patients with enough bone across the arch to place six straight implants, patients with heavy bites or a history of bruxism, and anyone who wants the extra long-term redundancy of two more anchor points. It is often preferred for the upper jaw, where softer bone makes the added support worthwhile.

Neither protocol suits someone who cannot commit to lifelong hygiene, or whose medical status makes elective surgery unsafe. Your surgeon will screen for uncontrolled diabetes, active gum disease and heavy smoking. Check that any clinician offering full-arch implants is on the General Dental Council's public register, and specialist standards for oral surgery are set out by the Royal College of Surgeons of England Faculty of Dental Surgery.

Practical decision framework for UK patients

A short checklist to guide the conversation with your surgeon:

1. Start with a CBCT scan. Bone volume decides most of this argument.
2. Match the protocol to your anatomy. Thin bone at the back points to All-on-4. Generous bone all round opens the door to All-on-6.
3. Weigh the budget honestly. All-on-4 saves several thousand pounds per arch. If that is the difference between fixed teeth and no treatment, it is a serious argument in its favour.
4. Factor in bite and bruxism. Heavy grinders often benefit from the extra load sharing of All-on-6.
5. Think in decades. More implants mean more redundancy if one is lost in year ten or fifteen.
6. Check the clinician and the brand. Confirm GDC registration and insist on a documented implant brand. Our comparison of Straumann, Nobel Biocare and MegaGen in the UK explains what those brand names actually buy you.
7. Get more than one quote. Two or three itemised quotes will show you quickly which recommendation is genuinely tailored to your case.

Frequently asked questions

Is All-on-6 always better than All-on-4?

No. All-on-6 offers more implants, more even load sharing and more redundancy, all real advantages when anatomy and budget allow. But All-on-4 is designed for patients who lack generous bone at the back of the jaw, and it has a strong long-term evidence base at a lower price. If your bone, bite and finances all point to All-on-6, it is often the more resilient choice. If your bone is limited or your budget is tight, All-on-4 is not a compromise, it is a well-studied protocol in its own right.

How much do All-on-4 and All-on-6 cost in the UK in 2026?

For 2026 UK private treatment, All-on-4 typically ranges from 12,000 to 18,000 pounds per arch, and All-on-6 from 15,000 to 22,000 pounds per arch, including implants, abutments and both the same-day and final bridges. A full mouth of All-on-4 is generally 22,000 to 32,000 pounds, and a full mouth of All-on-6 is 28,000 to 40,000 pounds. Prices vary with city, clinic reputation, implant brand and bridge material. NHS funding for full-arch implants is only available in narrow medical situations, so these are almost always private costs.

How long does All-on-4 or All-on-6 treatment take?

Both protocols usually deliver a same-day fixed provisional bridge on the day of surgery, so patients leave with teeth rather than an empty jaw. The final bridge is fitted after the implants have integrated, which normally takes three to six months. All-on-4 tends to move slightly faster because grafting is rarely needed. All-on-6 sometimes adds a few months if bone augmentation is required first. Plan on four to nine months for a straightforward case, longer if grafting is involved.

What happens if one implant fails on an All-on-4 bridge?

Losing one implant on an All-on-4 arch is significant because the bridge only has four anchor points. In many cases the whole bridge has to be redesigned, and a replacement implant is placed once the site has healed. This is one reason some surgeons prefer All-on-6 for younger patients or heavier bites. On an All-on-6 arch, a single failure can often be managed by continuing on the remaining five. Regular hygiene visits and prompt attention to looseness or bleeding around the bridge are the best way to catch problems early.

Can I convert my dentures directly to All-on-4 or All-on-6?

You cannot simply retrofit implants under an existing denture. Full-arch implant treatment is a fresh, planned reconstruction based on a CBCT scan and a new prosthetic design, not an add-on. Patients frustrated with removable dentures are a very common route into full-arch implants, and many UK clinics see the transition from dentures to a fixed bridge as their main workload. Our comparison of All-on-4 versus dentures and what patients wish they had known covers the honest trade-offs.

Which protocol is safer over 20 years?

Both are considered safe long-term treatments when placed by an experienced surgeon and maintained properly. Published data shows ten-year survival in the mid-90s per cent for All-on-4 and similar or slightly higher figures for All-on-6. The safer choice for you is the one that matches your bone, your bite and your medical status. What moves the twenty-year outcome most is not the number of implants but the quality of the surgery, the discipline of your daily cleaning, and turning up for annual maintenance visits.