All-on-6 vs All-on-4 Dental Implants: Which One and What's the Difference?

Four implants to hold a full jaw of teeth: all of your new teeth connect together as one bridge, and that bridge sits on just four implants. That's All-on-4, and it's one of the most elegant solutions in modern dentistry. But then someone mentions All-on-6, and a question appears that wasn't there before: if four implants work, why would anyone want six? And if six is better, why doesn't everyone get six?

The answer is satisfyingly specific. The lower jaw is dense and strong, so four implants do the job beautifully. The upper jaw is softer, which is why six implants there give better long-term stability. Most people end up with four on the bottom and six on the top, though the exact recommendation depends on the bone. And the price difference between them, which is £3,000-£6,000 per jaw, is worth understanding.

And just so you don't get the image in your mind of having only four teeth on the bottom and six on the top: These are the implants we're talking about here. The contact points that your new teeth go all on. Now you know why they're called all-on-4 and all-on-6.

The Cost Difference Between Them

All-on-4 runs £8,000-£16,000 per jaw, which comes to roughly £20,000-£30,000 for both upper and lower. All-on-6 runs £11,000-£22,000 per jaw, so £25,000-£40,000 for both. The extra cost comes from two additional implant fixtures, slightly longer surgery, and a bridge design that distributes force across six points instead of four.

How All-on-4 Dental Implants Work

The concept has been around for over two decades, and the clever bit is how the implants are positioned. The two at the front go in straight. The two at the back go in at an angle, which lets them grip into stronger bone while avoiding the areas that would cause problems. A full arch bridge clips across all four, holding 10-14 teeth per jaw, and the ten-year survival rates sit at 94-98%, which is excellent by any measure.

The lower jaw suits four implants particularly well because the bone there is naturally dense and strong. Four well-placed implants provide more than enough support.

So Why Would Anyone Want Six?

The upper jaw. That's really where the conversation starts, because the upper and lower jaws are, structurally speaking, completely different beasts.

The lower jaw is dense, compact, strong. Four implants in the mandible have more than enough bone to grip onto, which is why All-on-4 works so brilliantly there. The upper jaw though is softer, more porous, and has the maxillary sinuses taking up space where bone could be. Each implant simply has less to hold onto. Two extra implants spread the chewing force across a wider area, so each one carries less load. And if one of them doesn't integrate perfectly, the other five keep the bridge rock solid. With four in soft bone, there's less margin for that kind of thing.

The ten-year survival rates are actually very similar for both approaches (94-98% for each), which surprises people. The difference isn't about whether the treatment works; it's about how much safety margin is built into the system. In dense lower jaw bone, four implants have plenty. In softer upper jaw bone, six buy breathing room.

Most implant specialists recommend four for the lower and consider six for the upper, especially for patients with softer bone or a history of bone loss from gum disease.

The Hybrid: Four Below, Six Above

Something that's becoming increasingly common, and for good reason: All-on-4 in the lower jaw, All-on-6 in the upper. Ten implants total instead of eight or twelve, which recognises that the two jaws are fundamentally different structures and treats them accordingly.

The cost for this hybrid sits around £22,000-£35,000 for both jaws, depending on the bridge material and the region. Many experienced implant surgeons consider this the optimal balance of cost, engineering, and clinical outcomes for full mouth restoration.

What Determines the Choice

The decision isn't one you need to make before walking into a consultation. It emerges from what the CT scan shows about your bone.

If the scan reveals good, dense bone in both jaws, All-on-4 provides excellent results at a lower cost. If the upper jaw is softer or has experienced significant resorption, six implants there offer meaningful extra security. Teeth grinding is a consideration too, since grinders exert two to three times normal biting force over decades, and extra implants provide additional resilience against that. Even the bridge material plays a role: a heavier zirconia bridge transmits forces differently from a lighter acrylic one, and some clinicians prefer six implants when placing zirconia in the upper jaw.

The clinician who's looking at your three-dimensional bone scan has information you don't. If they recommend six, it's because your bone tells a story that benefits from the extra support. If they recommend four, the bone is strong enough that additional implants would add cost without adding meaningful benefit.

Surgery and Recovery

The surgical experience is similar for both. All-on-4 takes 2-3 hours per jaw. All-on-6 takes 2.5-4 hours, the extra 30-60 minutes for two more implant sites. Both approaches provide same-day teeth: the temporary bridge is fitted immediately, and you walk out with a full set of functioning teeth that day.

IV sedation is available for anyone who'd rather the procedure pass without awareness. Recovery is the same for both: swelling peaking at 48-72 hours, soft foods for the first few weeks, most people back to normal activities within a week. The two extra implant sites don't change the recovery experience because the surgical area is the same: the jawbone under the gum.

What About Years Down the Line?

One thing that's nice about this decision: whichever you go with, the ongoing maintenance is identical. Professional cleaning twice a year (the hygienist uses specialised instruments to get under the bridge where a toothbrush can't reach), a water flosser or interdental brushes at home, and that's really it. The implants themselves are titanium, so they can't decay, though the gum tissue around them still needs looking after the same way natural gums do.

The bridge on top is where the long-term maths gets interesting. An acrylic bridge lasts about 10-15 years before it needs replacing (£1,500-£3,000 for the lab work, and the implants underneath stay exactly where they are). A zirconia bridge lasts 20-25 years or potentially longer, which is part of why some people choose the higher upfront cost. Either way, the four-vs-six decision makes no difference to any of this. Once the bridge is in place, the foundation underneath is invisible.

The Consultation

At UrgentCare Dental, the implant consultation includes CT imaging and a thorough assessment of bone volume and density. The recommendation comes from the clinical picture rather than a one-size-fits-all philosophy. Payment plans can spread the cost across manageable monthly instalments, and knowing the exact figure before committing means the financial decision is as informed as the clinical one.

Four implants hold a full jaw of teeth. Six hold a full jaw with extra security. Both have decades of clinical evidence, excellent success rates, and outcomes that genuinely transform lives. The right answer is the one that matches your anatomy, and the consultation is where that answer becomes clear.