What is All-on-6? How it differs from All-on-4, and who it suits

All-on-6 is the general name given to fixed bridge plans that carry all the teeth in one jaw on six implants. In practice it is used without sticking to a single, standard definition, so two clinics using the same name may mean different things: whether all the implants are upright or the back ones are tilted, and whether the bridge is a single piece or divided into sections. When you compare quotes, you need to ask about these details rather than go by the name itself.

The basic difference from All-on-4 is how the load is distributed. In a four-implant plan, the implants are gathered at the front and middle of the jaw; the two back implants are tilted to avoid the sinus in the upper jaw and the nerve canal in the lower jaw. In a six-implant plan, two more implants are added, usually further back. This spreads the points the bridge rests on along the jaw and divides the load among more supports.

What this means in concrete terms for the bridge is the extension. The part of the bridge that sits behind the last implant works like a lever when you bite and increases the load on the implant furthest back. When there is support at the back as well, this extension gets shorter or is not needed at all. In four-implant plans, some of the back teeth sit on this extension, so the length of the bridge and the bite are planned with particular care.

The second gain from six implants is spare capacity. In a four-implant bridge, losing one implant means losing a quarter of the points the bridge rests on, and the plan has to be reassessed. With six implants, if the number and distribution of the remaining implants are adequate, the bridge can go on being carried for a while; the area of the loss is replanned in the meantime. In some plans, having more implants also makes it possible to make the bridge in sections rather than as a single piece.

The other side of the coin is bone. The areas at the back where the two extra implants go are where bone shrinks most after tooth loss. At the back of the upper jaw the sinus drops down, and at the back of the lower jaw the nerve canal comes closer to the surface of the bone. If these areas lack the height a conventional implant needs, a six-implant plan either requires a sinus lift (sinus floor elevation) and adding bone, or is adapted by tilting the back implants as well. A systematic review reports that bone loss around tilted implants is not significantly different from bone loss around upright implants.

So are six implants safer? Research does not answer this question with as clear a yes as people assume. Using four to six implants for a full-mouth fixed bridge has been a well-documented option for a long time. A comprehensive systematic review found no significant difference in implant or bridge survival between fewer than five implants per jaw and five or more. A 2026 meta-analysis directly comparing All-on-4 with All-on-6 also reports similar results for the two plans; however, it stresses that the variation between studies is high and that the results should be interpreted with caution.

This result does not mean 'the number makes no difference'; it shows that the number is not decisive on its own. The patients in the studies were put on a plan because they were judged suitable for it: four implants were placed in jaws with enough bone at the front, and six in jaws that also had bone at the back. So the right question is not 'four or six?' but whether your jaw has the bone to carry six implants, and whether an additional procedure is needed for that.

The strategic implant is a third route in this debate. Because it takes its anchorage not from the volume of spongy bone but from the hard outer layer of the jaw, the implants can be spread across the whole jaw even if the bone at the back has shrunk. In this approach the number of implants is not limited to four or six; the load is usually shared among a larger number of thin implants and, if the anchorage is adequate, a fixed bridge can be fitted the same week. With this method, as used at Implant72, the teeth fitted on day 3 are the final teeth; no second bridge is made months later to replace them.

The first list describes the situations in which the advantage of a six-implant plan becomes clear, the second the situations in which another route may be more appropriate. Both become clear after a CBCT scan.

This sequence is for the decision, not for the treatment. At the end of it you know how many implants are planned, where, and on what grounds.

1. 1

   A three-dimensional CBCT scan

   The height, width and density of the bone are measured in every area of the jaw. The position of the sinus and the nerve canal shows whether the two extra implants can be placed without an additional procedure.

2. 2

   The bite and the opposite jaw

   What is in the opposite jaw, how you bite and whether you grind your teeth at night are assessed. The greater the load, the stronger the case for increasing the number.

3. 3

   Designing the bridge

   How many teeth the bridge will carry and how long an extension will be left behind the last implant are drawn up. The positions of the implants are worked out from this design, not the other way round.

4. 4

   Setting the options side by side

   For the same jaw, a four-implant tilted plan, a six-implant plan and, if needed, a plan with added bone are discussed, each with the additional procedures and timeline it involves.

5. 5

   Measuring anchorage during placement

   The resistance of each implant as it seats in the bone is measured. In an area where the expected value is not reached, the plan may change; whether the bridge is fitted in the first week depends on this measurement.

6. 6

   Sharing the plan in writing

   How many implants, in which areas, at what angle, with what bridge material and whether an additional procedure is needed should be given to you in writing.

None of the plans below is superior to the others in every case. The difference between them is what bone they need and how they share the load.

We write these so that you can ask the right questions at whichever clinic you go to.

The course below describes a classic All-on-6 immediate loading plan that starts with a temporary bridge. In the Implant72 protocol, the final teeth are fitted on day 3 and there is no stage of moving from a temporary bridge to a permanent one; afterwards there are only check-ups. If bone has been added, or if fusion has to be waited for, the timeline stretches by months.

1. Surgery and the first days

   All the implants are placed in the same session. If the anchorage is adequate, a fixed bridge is fitted within the first week. Swelling and tenderness are in proportion to the area the surgery covers; implants placed at the back widen that area.

2. The first weeks

   You start with soft food, and the chewing load is increased step by step. Hard food is avoided: the implants have only just been placed, and in classic plans the temporary bridge is also more fragile than the permanent one.

3. Moving to the permanent bridge in the classic plan

   In classic plans, the permanent bridge is made once the gum and bone have settled into their new shape, and the timing of the change is decided at check-ups. In the Implant72 protocol this step does not exist; the final teeth have been in the mouth since day 3, and during this period there are only check-ups.

4. The long term

   The tightness of the screws, the bite and the bone around the implants are checked at regular intervals. An interdental brush and a water flosser are a permanent part of daily care.

There are no figures on this page, but the difference in scope between the two plans is concrete. These are the items that set the scope:

Number of implants and number of jaws

Compared with four implants, six mean two more surgical sites, two more implants and two more connecting components. Whether one jaw or both are treated doubles this difference.

Additional procedures at the back

If a sinus lift or added bone is needed for six implants, the scope widens markedly and the timeline gets longer. Whether it is needed is decided after the CBCT scan.

The material and structure of the bridge

Bridges of different materials can be made on the same number of implants; whether the bridge is a single piece or in sections also changes how it is made.

The temporary bridge stage

In classic immediate loading plans, a temporary bridge is made first and the permanent bridge months later; whether both are included in the scope should be set out in writing from the start. In the Implant72 protocol, the final teeth fitted on day 3 are the only bridgework, and there is no separate item for a temporary bridge.