What Is All-on-4? Full-Arch Dental Implants Explained

All-on-4 is a full arch implant treatment that replaces a whole upper or lower set of teeth using four implants and one fixed bridge. Two implants go in straight at the front of the jaw. The back two are angled, which lets them anchor into denser bone further forward and often avoids the need for a bone graft.

That's the concept in one paragraph. The reality takes a bit longer to explain, and there are a few things about all on 4 treatment that the marketing tends to skip over.

Here's something that surprises people. Most of the full arch enquiries Bradbury Dental Surgery sees aren't from patients with no teeth at all. They're from patients who still have eight or ten teeth left, and most of them are failing. Australian survey data backs that up: around 4 per cent of adults have lost all their natural teeth, but close to 14 per cent have what the Australian Institute of Health and Welfare calls a non-functional dentition, meaning fewer than 21 teeth. That second group is much larger, and it's the group most likely to be weighing this decision.

What Is All-on-4 and How Does It Work?

All-on-4 works by using the bone you already have rather than rebuilding bone you've lost.

When teeth are missing for a long time, the jawbone that used to hold them shrinks. It resorbs. The bone at the back of the jaw usually goes first, and in the upper jaw the sinus drops down into that space, leaving very little to work with. Traditionally that meant grafting, waiting months for the graft to mature, then placing implants. A long process, and an expensive one.

The angled approach sidesteps a lot of that. By tilting the two rear implants forward at roughly 30 to 45 degrees, they can be seated in the denser bone at the front of the jaw while their tops still emerge far enough back to support a full bridge. You get support across the whole arch from four implants instead of six or eight.

Why four and not more?

Four is the minimum number that reliably resists the twisting forces of chewing across a full arch. Fewer than that and the bridge can rock. More than four is sometimes better, and we'll come back to that when we look at All-on-6.

What holds the teeth on?

The bridge screws onto the implants through angled connectors called abutments. You can't take it out. Your dentist can unscrew it for cleaning and servicing, but it stays put when you eat, talk, and sleep. That's the main practical difference between this and a denture.

What Happens During the All-on-4 Procedure?

The all on 4 procedure runs across several appointments, usually spread over four to eight months from start to finish.

1. Assessment and scanning. A 3D scan and x-rays map your bone volume, density, nerve position and sinus location. That scan tells us whether four implants will actually work for you, or whether you need a different plan.

2. Planning. Implant positions and angles are worked out digitally before anyone touches your mouth. A surgical guide is often made from that plan.

3. Extractions and implant placement. Any remaining teeth in that arch come out, the implants go in, and this all happens in one surgical visit. Local anaesthetic is standard, and IV sedation is available for patients who'd rather not be aware of the surgery.

4. The provisional bridge. A temporary fixed bridge is fitted, usually the same day or within a day or two.

5. Healing. The implants fuse with the bone over the next three to six months. This is osseointegration, and it can't be rushed.

6. The definitive bridge. Once the implants have integrated and your gums have settled into their final shape, the temporary comes off and your long-term bridge goes on.

That gap between step four and step six is the part patients most often don't expect.

Do You Really Get Teeth in a Day?

You get a set of teeth in a day. You don't get your final set.

The single most common thing our dentists end up correcting in a first consult is this one. "Teeth in a day" refers to the provisional bridge, which is fitted immediately so you never have to walk around without teeth. It's a real benefit and it matters to people. But the provisional is not the finished product.

It's usually made of acrylic. It's a bit bulkier, the shade and shape are a first approximation, and it's built to tolerate a jaw that's still healing and changing shape underneath it. You'll live with it for months while your gums shrink back to their settled contour.

The definitive bridge is made afterwards, once things have stopped moving. Better materials, better fit, better aesthetics.

Any clinic that lets you believe the same-day teeth are your final teeth is setting you up to be disappointed at month three. We'd rather you know now.

All-on-4 vs All-on-6 vs Implant-Supported Dentures

Full arch isn't one treatment. It's a family of them, and the right one depends on your bone, your bite and your budget.

Option	Implants per arch	Fixed or removable	Best suited to	Trade-offs
All-on-4	4	Fixed (dentist-removable only)	Reduced bone volume, patients wanting to avoid grafting	Less margin for error if one implant fails
All-on-6 / All-on-X	6 to 8	Fixed	Good bone volume, heavy bite forces, grinders	Higher cost, more surgery, may need grafting
Implant-supported overdenture	2 to 4	Removable by you	Tighter budgets, patients who want easier cleaning	Still a denture, covers the palate in some designs
Conventional full denture	0	Removable	Lowest cost, medically complex patients	Movement when eating, ongoing bone loss continues

"All on x" is just the generic version of the same idea, where the x stands for however many implants your case calls for. Some clinics use it to avoid the branded terminology. The underlying treatment is the same principle applied with a different implant count.

Worth knowing: All-on-4 is a registered trademark for a specific protocol developed by one implant manufacturer. Plenty of practices use the phrase loosely to mean any four-implant full arch bridge. If you're comparing quotes between clinics, ask which implant system is actually being placed, because it affects the cost of servicing and spare parts years down the track.

Who Is a Candidate for All-on-4, and Who Isn't?

Most people with a failing or fully missing arch can be assessed for full arch implants.

Not everyone should proceed with four.

Things that generally point to a simpler case:

• Enough bone height and width at the front of the jaw

• Reasonable general health and controlled chronic conditions

• Non-smoker, or willing to stop

• Gum disease treated and stable before surgery

• Able to commit to regular reviews afterwards

Things that give our dentists pause:

• Heavy smoking: Smoking raises the risk of early implant failure and later infection around the implant. We'll usually ask patients to stop well before surgery.

• Uncontrolled diabetes: Poorly managed blood glucose slows healing and interferes with integration. Well-controlled diabetes is a different story and is usually fine.

• Severe grinding: This one is underrated. We've seen more full arch cases run into trouble from undiagnosed bruxism than from anything to do with the implants themselves. Implants don't have the shock-absorbing ligament that natural teeth have, so grinding forces transfer straight through to the bone and the bridge. Most of these patients need an occlusal splint as part of the plan, not as an afterthought.

• Severe bone loss at the front of the jaw: The whole design depends on solid bone in the anterior region. If bone loss has advanced that far, four implants may not be enough, and grafting or a different approach comes back onto the table.

• Medications affecting bone metabolism: Some osteoporosis drugs change how bone heals after surgery. Bring your full medication list to the consult.

When we take a scan and the bone at the back of the lower jaw is thin, or the sinus has dropped low on the upper, that changes the conversation. Sometimes for the better, because that's exactly the situation the tilted design was made for.

What Does All-on-4 Cost in Australia?

Full arch implant treatment commonly starts somewhere around $23,000 per arch in Australia and can run past $30,000 depending on materials, the number of extractions, whether grafting is needed, and whether you have sedation.

A few things that affect where you land in that range:

• Bridge material. Acrylic on a titanium frame sits at the lower end. Zirconia costs more and generally lasts longer.

• Extractions. Removing ten failing teeth adds surgical time.

• Sedation. IV sedation is an added cost, and for many patients it's worth it.

• One arch or two. Doing both arches together costs more upfront but usually less than two separate treatments.

On the funding side, be realistic. Medicare doesn't cover implants. Private health extras cover major dental, but annual limits sit well below the cost of a full arch, so the rebate covers a slice rather than a serious portion. DVA arrangements have their own prior approval requirements, so check before you assume coverage. We do offer payment plans including Afterpay, Zip and National Dental Plan.

Any figure you read online, including ours, is an indication. The only number that means anything is the one written on a quote after someone has scanned your jaw.

How Long Does All-on-4 Last, and What Maintenance Does It Need?

Two different lifespans get confused here, and the difference matters.

The implants. Published long-term studies of tilted full arch protocols report implant survival in the mid-90 per cent range at ten years. Those figures vary between studies and depend a lot on smoking, grinding and how well the case was maintained.

The bridge. This is the shorter number. An acrylic bridge commonly needs significant repair or replacement somewhere between five and ten years. Teeth wear, acrylic chips, screws loosen. Zirconia typically holds up longer. Nobody tells you this part in a sales consult, but you should budget for it.

Ongoing care looks like this:

• Cleaning underneath the bridge daily with a water flosser or superfloss, because food packs under there

• Reviews every six months so we can check the screws and the tissue around each implant

• A professional clean where the bridge is sometimes unscrewed for access

• A splint if you grind

Peri-implantitis, which is inflammation and bone loss around an implant, is the main long-term threat. It behaves a bit like gum disease and it's largely preventable with proper cleaning and regular reviews. Skip the maintenance and the implants that were doing fine at year three can be in trouble by year eight.

Risks and Complications Worth Understanding First

Every surgical procedure carries risk, and you should hear about these before you commit rather than after.

• Implant failure to integrate, which usually shows up in the first few months and often means replacing that implant

• Infection around the surgical site

• Nerve irritation in the lower jaw causing temporary or, rarely, lasting numbness of the lip or chin

• Sinus complications in the upper jaw

• Bridge fracture or screw loosening

• Speech changes in the early weeks while your tongue adjusts to the new shape

Most of these are manageable when they're picked up early. That's a large part of why the review schedule exists.

Thinking About Full Arch Implants?

If you've got an arch of failing teeth, or you're tired of a denture that moves, it's worth getting properly assessed before you compare prices. A scan and an examination will tell you whether four implants suit your bone, or whether six, an overdenture, or something else entirely makes more sense for you.

We see patients from across Campbelltown, Camden, Narellan and the wider Macarthur region for exactly this conversation. Our dental implants page covers our implant options in more detail, and if your case involves rebuilding both arches, our full mouth rehabilitation page explains how that's planned. If you'd rather start by comparing against removable options, have a look at dentures first.

Call Bradbury Dental Surgery on (02) 4628 2151 or book online. After 30 years of treating families across the Macarthur region, we'd rather spend an hour explaining your options than have you commit to something on the basis of a brochure.

For general background on implants, healthdirect has a plain-language overview worth reading.

Frequently Asked Questions

Is the All-on-4 procedure painful?

The surgery itself is done under local anaesthetic, with IV sedation available, so you shouldn't feel the procedure. Afterwards, expect swelling, bruising and soreness for several days, managed with prescribed pain relief. Most patients describe the recovery as more uncomfortable than a single extraction but more manageable than they expected.

How long is recovery after full arch implants?

Most of the swelling settles within a week to ten days. You'll be on a soft diet for six to eight weeks while the implants integrate, and normal chewing usually resumes once the definitive bridge is fitted. Full integration takes three to six months.

Can All-on-4 be removed?

Not by you. The bridge is screwed onto the implants and stays in place while you eat and sleep. Your dentist can unscrew it for servicing and deep cleaning, which is done at review appointments.

What happens if one implant fails?

With four implants, losing one affects the support of the whole bridge, so it needs attention quickly. Depending on where it is and how much bone remains, the implant can often be replaced after a healing period, sometimes with a temporary denture in between. This is one reason some patients with heavy bite forces are better suited to six implants.

Am I too old for dental implants?

Age on its own isn't a barrier. General health, healing capacity, medications and bone quality matter far more than the number. We've placed implants in patients in their eighties who healed well, and declined cases in much younger patients whose health made surgery a poor idea.