Does four or six change the bridge on top?
Mostly no. The same materials are used on four and six implants. What changes is how the framework is designed to span between the supports.
Medically reviewed by Dt. Hüseyin Yavuz Özbek, implant surgeon · Updated October 2026Both four- and six-implant bridges are usually made from zirconia, or from acrylic teeth on a metal framework such as titanium. With four implants, the bridge spans longer gaps and the back of it may extend past the last implant, so the framework has to be stiff. With six, the supports are closer together. A 2024 review linked computer-milled frameworks with better implant survival in six-implant upper jaws.
The same materials on both
| Bridge type | What it is | Worth knowing |
|---|---|---|
| Zirconia | A very hard, tooth-coloured ceramic, milled as one piece | Strong and stain-resistant; can chip; harder to adjust |
| Acrylic on a titanium bar | Acrylic teeth and gum on a stiff metal framework | Lighter and easier to repair; wears and stains more over time |
| Temporary bridge | Acrylic, fitted in the first days | Protects the implants while they heal; replaced later |
Where four and six differ
On four implants
Longer spans between supports, and the back of the bridge may extend past the last implant (a cantilever). Tilting the back implants shortens that extension. The framework needs to be stiff.
On six implants
Supports are closer together and further back, so spans and any extension are shorter. In a 2024 review of upper jaws, computer-milled frameworks were linked with better implant survival in the six-implant group.
Questions to ask about the bridge
- What will the final bridge be made of, and why for my bite?
- Is the framework computer-milled? What metal?
- How far does the bridge extend past the last implant?
- What happens if it chips: can it be repaired, and where?
- Is the temporary bridge included, and how long will I wear it?
The bridge material can change the price. For the cost side, see allon6cost.co.uk.
Common questions
Is zirconia or acrylic better on four implants?
Both are used. Zirconia is very hard and resists staining but can chip and is less forgiving on the opposite teeth; acrylic on a titanium framework is lighter and easier to repair. Your dentist should explain why they suggest one for your bite.
Are the temporary teeth the same as the final ones?
No. Temporary teeth fitted in the first days are usually acrylic, made to protect the healing implants. Final teeth are made once the implants have bonded with the bone.
What is a titanium bar?
A framework, often milled by computer from a single block, that sits inside an acrylic or composite bridge to make it stiff and strong across the span between implants.
Sources
- Sharaf et al. (2024), Heliyon — Four or six implants for maxillary fixed prostheses: systematic review and meta-analysis (framework material)
- NHS — Dental treatments (bridges, implants)
- Oral Health Foundation — Understanding dental implants
Checked October 2026. Where we give our own view as a clinic, we say so.
Only a scan can settle it.
Send us an X-ray or scan if you have one. A dentist will tell you which option suits your bone, and say so honestly if neither is the right step.