Replacing a whole jaw of teeth with individual implants would need eight, ten or more, and in a jaw that has been without teeth for years there is often not enough bone left to place them without grafting first. All-on-4 is a way around that: four implants per jaw, with the two at the back placed at a deliberate angle, carrying a fixed bridge of twelve or more teeth.
- Implants per jaw
- Four — two vertical at the front, two angled at the back
- What it carries
- One fixed bridge, not individual crowns
- Removable by you
- No. It is fixed and removed only by a dentist
- Final bridge
- Usually months after placement, once healing is complete
Why two implants are tilted
The bone at the front of the jaw stays denser and taller for longer than the bone at the back, and behind it sit two structures nobody wants to disturb: the sinus in the upper jaw and the nerve canal in the lower. Placing the rear implants vertically would mean either grafting, or not reaching solid bone at all.
Tilting them — commonly around thirty to forty-five degrees — lets them engage the dense bone at the front while their heads emerge further back. That does two useful things: it uses available bone rather than added bone, and it spreads the support of the bridge over a longer span, which reduces the unsupported overhang at the end.
What "teeth in a day" means, and does not
The technique is often provided with a temporary bridge fitted very shortly after surgery. That is real, and it is one reason people choose it — you do not go home without teeth.
What it is like to live with
- It is fixed. You do not take it out, and it does not move when you eat or speak — the difference most people notice against a denture.
- It has to be cleaned underneath. There is a gap between the bridge and the gum by design, and it needs a specific brush or irrigator daily.
- Diet is restricted while the implants integrate, typically soft for a period set by the surgeon.
- It is a single component. A problem in one part means the bridge comes off to be worked on.
The cleaning is the part most underestimated. A fixed bridge on four implants is easier to live with than a denture and harder to clean than natural teeth, and peri-implantitis around one of four implants is a more serious problem than it would be around one of ten.
Is four really enough?
For suitable cases, yes — the concept has long-term published follow-up. Suitability is the operative word: it depends on bone volume and quality, bite forces and whether you grind. Some cases are planned with five or six for that reason.
What if one implant fails?
It is a significant event because there are only four. Depending on which one and on the bone available, it may be replaced, or the bridge redesigned. This is why the follow-up schedule matters more here than with single implants.
Will it look like a denture?
A well-made bridge does not, but it is not identical to individual teeth either — it usually includes a section that replaces lost gum, because the tissue that was there is gone. Ask to see the design before it is made.
Can I have it if I have been without teeth for years?
Often, and that is much of the point of the technique. It still depends on what bone remains, which is a question a scan answers and a website cannot.