All-on-4 and All-on-6 are the two names you will meet when a full arch needs replacing. The difference is not marketing: it is how many implants carry the bridge, and that changes who qualifies, how the load is spread, and what happens if one implant is lost. Dent Health Istanbul is a dental clinic in Istanbul, Turkey, and this guide sets out the real trade-off.
What the numbers mean
Both techniques replace a full arch of teeth with a single fixed bridge screwed onto implants. All-on-4 uses four, typically with the two rear implants angled to reach denser bone at the front of the jaw. All-on-6 uses six, spreading the same bridge across more support points.
In both cases you end up with one bridge, not individual teeth. That is the part patients most often misunderstand: you are not getting twelve separate implants with twelve crowns.
Who qualifies for four, and who needs six
The deciding factor is bone — how much you have, where it is, and how dense it is. All-on-4 exists precisely because many patients who have lost teeth have also lost bone height at the back of the jaw. Angling the rear implants forward uses the bone that is still there and avoids grafting.
All-on-6 asks for more bone in more places. Where that bone exists, the extra two implants give a shorter unsupported span and a more even spread of force. Where it does not, the honest answer is four implants or a graft first — not six placed into bone that cannot hold them.
Whether your own jaw suits four or six is a question for a CT scan, not an article. Send us your imaging and we will tell you which your bone actually supports.
How load is distributed
A fixed bridge on four implants has longer spans between supports, particularly at the back where the cantilever sits. More supports mean shorter spans, less flex and less stress on each implant and on the bridge framework itself.
This matters most if you chew hard, if you have a powerful bite, or if the opposing arch is also fixed rather than a denture. Two fixed arches biting against each other generate considerably more force than a fixed arch biting against a removable one.
What happens if an implant is lost
This is the practical argument for six, and it rarely appears in brochures. Lose one implant out of six and the bridge usually remains serviceable while the site heals and is re-treated. Lose one out of four and the bridge is, in most cases, no longer supportable as it stands.
It is not a reason to choose six regardless of bone. It is a reason to ask what the recovery plan looks like for whichever option you are offered.
Durability and maintenance
Both approaches are long-term solutions when they are planned correctly and maintained. What shortens their life is almost never the implant count: it is uncontrolled gum disease around the implants, grinding without protection, and skipped hygiene appointments.
A fixed full arch needs professional cleaning under the bridge on a schedule. Ask how often, and who will do it in your own country between visits. If nobody has mentioned this to you, that is a gap in the plan.
Questions to settle before you book
| Ask for | Why it matters |
| A CT scan read, in writing, saying what your bone supports | Four or six is a bone decision. A recommendation made before imaging is a sales decision. |
| The implant brand, diameter and length for each position | These four details are what any dentist in your country needs to service the work later. |
| What the temporary bridge is, and how long you wear it | Full-arch treatment is staged. You should know what you fly home with. |
| The recovery plan if one implant fails | The answer differs sharply between four and six. Get it before you decide, not after. |
| The hygiene schedule and who performs it at home | Maintenance decides the lifespan more than the implant count does. |
| The written guarantee, per component | Implant, abutment, framework and teeth may carry different periods. |
What the treatment actually looks like, stage by stage
Full-arch treatment is not one appointment and it is rarely one trip. Knowing the sequence in advance is the difference between a planned journey and an improvised one.
Imaging and planning. A CT scan, read before anything is agreed. This is where four or six is decided, along with implant positions, lengths and whether any grafting is needed.
Extractions, if teeth remain. Often done at the same visit as placement, which is why the first stage is the longest.
Implant placement. Surgical, under local anaesthetic with sedation available. Stability is measured as each implant seats, and this is the moment at which immediate loading is confirmed or ruled out.
The temporary bridge. If stability allows, fitted during the same trip. You fly home with teeth, not a gap.
Integration. Months, at home, wearing the temporary. Nothing accelerates this.
The final bridge. A second trip: impressions or scans, a try-in, and fitting. This is the visit where the shape, shade and bite are settled, so do not let it be rushed.
Living with a fixed full arch
Two adjustments catch patients out. The first is cleaning: you need interdental brushes or a water flosser to reach under the bridge, and a toothbrush alone will not do it. The second is that the bridge is one piece — if a tooth on it chips, the repair involves the bridge, not that tooth.
Neither is a drawback so much as something to know before you commit. Ask to be shown the cleaning technique on your own bridge before you fly home, and ask what the repair route is for a chipped tooth on the framework.
Which is right for you
Significant bone loss at the back of the jaw: All-on-4 is often the only fixed option that avoids grafting, and it is a well-established one.
Adequate bone throughout the arch, a strong bite, or a fixed arch opposing: All-on-6 spreads the load better and leaves you more margin if a site is lost.
Unsure, or you have been quoted one without a scan: get the scan read first. Either number can be the right answer; only your imaging says which.
Frequently asked questions
Is All-on-6 always better than All-on-4?
No. Six implants placed into insufficient bone is worse than four placed well. All-on-6 is better where the bone supports it, which is exactly why the scan comes before the recommendation.
Do I get teeth the same day?
Immediate loading with a temporary bridge is often possible, but it depends on how firmly the implants seat at placement. It is assessed during surgery, not promised in advance. Ask what happens if immediate loading is not advisable on the day.
Will anyone be able to tell it is a bridge?
A well-made full arch is not obvious. What gives these restorations away is usually tooth proportion and the gum line, not the fact that it is fixed to implants.
Can I clean it normally?
Not quite. A fixed full arch needs interdental brushes or a water flosser under the bridge, plus professional cleaning on a schedule. Ask to be shown the technique before you fly home.
What if I grind my teeth?
Then a protective splint is part of the treatment, not an optional extra afterwards. Grinding is one of the few things that reliably damages a well-placed full arch.
Send us your CT scan or panoramic X-ray and we will tell you what your bone supports. Message us on WhatsApp with photos of your teeth, or request a free assessment. We reply with a written plan that names the materials.
Read more about All-on-4 and All-on-6 in Turkey, about single dental implants, how to read a clinic guarantee in our guide to dental warranties, and how treatment in Istanbul works in our dental tourism guide.
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