- Both All-on-4 and All-on-6 replace a full arch with a fixed, screw-retained bridge.
- All-on-4 uses two straight front implants and two tilted back implants — often avoiding bone grafts.
- All-on-6 adds two implants for wider load distribution — frequently preferred in the upper jaw and for strong biters.
- The decision comes from a CT scan, not a price list.
What the two concepts have in common
Both treatments replace every tooth in one jaw with a single fixed bridge. The bridge is screwed onto implants, so it never comes out at home, never needs adhesive and does not cover the palate.
In both cases, a fixed temporary bridge is usually fitted within 24–72 hours of surgery when the implants are stable enough for immediate loading. After 3–6 months of healing, the final bridge — typically zirconia or a titanium-reinforced hybrid — replaces it.
How All-on-4 works
All-on-4 uses four implants per arch. The two front implants are placed upright. The two back implants are tilted up to around 45°, which lets them:
- engage longer, denser bone further forward,
- avoid the sinus in the upper jaw and the nerve in the lower jaw,
- support teeth further back than an upright implant in the same position could.
This tilting is what allows many patients who were told they "don't have enough bone" to receive fixed teeth without bone grafting.
How All-on-6 works
All-on-6 places six implants per arch. The extra two implants reduce the load carried by each one and give the bridge more support along its length.
All-on-6 is commonly recommended when:
- the upper jaw bone is soft (lower density),
- the patient has a strong bite, grinds or clenches,
- the patient wants maximum redundancy for the long term,
- the bone volume comfortably allows six positions.
Side-by-side comparison
| All-on-4 | All-on-6 | |
|---|---|---|
| Implants per arch | 4 | 6 |
| Typical bone grafting | Often avoided | Sometimes needed |
| Load per implant | Higher | Lower |
| Often preferred for | Lower jaw, reduced bone | Upper jaw, strong bite |
| Surgery time | Shorter | Slightly longer |
| Cost | Lower | Higher (2 extra implants) |
Upper jaw vs lower jaw
The lower jaw usually has dense bone, and All-on-4 performs very well there. The upper jaw has softer bone and the sinuses above the back teeth. That is why upper arches are more often planned with five or six implants — or with zygomatic implants when bone loss is severe.
How the decision is made
At our clinic, the number of implants is decided after a 3D CT scan and a digital plan that maps:
- bone height, width and density in every position,
- the sinus and nerve,
- your bite and the opposing jaw,
- the smile design — where the teeth need to be.
The right number of implants is the minimum number that safely carries your bite for decades — not the cheapest one, and not the most expensive one.
The bottom line
If your scan shows good bone and a normal bite, All-on-4 is a proven, efficient solution. If your bone is softer, your bite is strong or you want additional security, All-on-6 is often the better plan. A specialist should show you both options with written pricing when both are realistic.
Your fixed smile starts with one message.
Send a photo or X-ray. Get a plan and a written price within 24 hours.