Four or six implants?
Either can carry a fixed arch of teeth. The difference comes down to how much bone you have and how the biting load is shared.
Clinically reviewed by Dt. Hüseyin Yavuz Özbek, implant dentist · Last checked October 2026A 2024 meta-analysis of 53 studies on the toothless upper jaw found no significant difference in implant or bridge survival between four and six implants, but more bone loss around the implants when four were used. Six spread the chewing force over more supports; four can be the better choice when bone at the back of the jaw is thin. Your 3D scan should decide.
The 2024 review in plain terms
In 2024 Sharaf and colleagues pooled the results of 53 studies on fixed bridges in the toothless upper jaw, published in the journal Heliyon. Their main findings:
- Implant survival and bridge survival showed no significant difference between four and six implants.
- Technical and biological complications did not differ significantly either.
- Bone loss around the implants was significantly greater with four.
- With six implants, a computer-milled (CAD/CAM) bar and a good front-to-back spread went with better implant survival.
The authors concluded that more implants may reduce complications and bone loss. Bear in mind this pools many separate studies; it is not a trial in which the same people received both designs. In your own case, your own scan counts most.
Side by side
| Four implants (All-on-4®) | Six implants (All-on-6) | |
|---|---|---|
| Layout | two straight at the front, two tilted at the back | spread more evenly around the arch |
| Bone needed | less; relies on the front of the jaw | more, including further back |
| If one implant fails | little in reserve | five supports remain |
| Bone loss in studies | greater | smaller |
| Surgery | a little shorter | two more implants per jaw |
| Precious Dental price, both jaws | £6,000 | £6,500 |
How the choice is usually made
Six is the natural choice when there is enough bone all the way round, when you bite hard or grind your teeth, and when you want a margin in case an implant is ever lost.
Four can make more sense when the back of the jaw has little bone. Tilting the rear implants makes use of the bone that is there and can avoid a graft or a sinus lift. That is the thinking behind Nobel Biocare's All-on-4® concept.
Our view as a clinic: we plan each case from a 3D scan and put in writing how many implants of which brand we recommend, and why. If four suits your bone better, we will tell you, even though six costs more.
Questions readers ask
So is six always better than four?
No. The studies show similar survival, with less bone loss for six. When the back of the jaw has little bone, four tilted implants can avoid a graft, which is a real advantage.
What if one implant fails?
With six, five remain and can often keep the bridge in place until the failed one is replaced. With four there is less to fall back on. At Precious Dental we replace a failed implant once, free of charge.
How much more does six cost?
At Precious Dental, All-on-4 is £6,000 and All-on-6 is £6,500, each for both jaws together, so the difference is £500.
Do I get a say?
Yes, but only once the 3D scan has been taken. Ask for the reason, in writing, why four or six is recommended for your jaw.
Sources
- Sharaf et al. (2024), Heliyon: four versus six implants in the edentulous maxilla, systematic review and meta-analysis
- Nobel Biocare: the All-on-4® treatment concept
- Precious Dental: guarantee terms
Checked in October 2026. Where we give our own view as a clinic, we say so.
Want an opinion on your own case?
Tell us what you are considering. A real person replies, and will say so plainly if All-on-6 is not the right step for you.