All-on-4 vs All-on-6: questions to ask before deciding

All-on-4 and All-on-6 are among the most heavily marketed treatments in Istanbul, and among the least well explained. The names sound like two competing products. They are not.

The number refers to how many implants carry a full arch of teeth. Everything else — the surgery, the materials, the bridge, the timeline, the cost, the aftercare — sits outside the name entirely.

What the concept actually is

Replacing every tooth in a jaw does not require an implant per tooth. A full-arch bridge can be supported by a small number of implants, provided they are positioned to spread the load.

"All-on-4" is a specific technique developed for this: four implants per jaw, the two at the back angled forward so they engage more bone and reach further back without entering the sinus or the nerve canal. "All-on-6" is the same idea with six.

Both are recognised approaches. Neither is inherently better. The right number depends on your bone, your bite and your jaw — which is a decision made from a CBCT scan, not from a price list.

What the number does not tell you

This is the important part, because the number is what gets advertised and almost nothing else does.

Which jaw. Upper and lower jaws behave differently. Lower bone is generally denser; upper bone is softer and the sinus is in the way. A plan that treats both jaws identically has not accounted for that.

The material of the bridge. Acrylic on a metal frame, monolithic zirconia and layered ceramic behave very differently in wear, repairability and cost. Two quotes both saying "All-on-6" can be describing completely different objects.

Whether the price is per jaw or for both. This is the single most common misunderstanding in full-arch quoting from anywhere. Establish it in writing.

Whether extractions are included. Most full-arch patients have teeth still to be removed. Ask whether extraction, and any bone smoothing at the same appointment, is in the price.

Whether the final bridge is included. See below. This is where most of the money hides.

Implant brand and system. Which system, which model, and what the long-term availability of components is. If you need a repair in six years, someone at home has to be able to obtain the parts.

Temporary versus final: where the cost actually sits

Full-arch cases are frequently done with immediate loading — a temporary bridge fitted at or shortly after surgery, so you do not leave without teeth. This is legitimate and it is one of the genuine advantages of the approach.

But the temporary is not the final bridge. It is usually acrylic, it is designed to get you through healing, and it will be replaced once the implants have integrated — which takes months.

So a one-week All-on-4 package is entirely possible, and what you fly home with is very often the temporary. The questions that follow are not sceptical, they are just the questions:

• Is the bridge I leave with the final one, or a temporary?
• When is the final one fitted, and does that need a second trip?
• Is the final bridge in this price?
• If I need the temporary repaired or relined while I am at home, who does that and at whose cost?

A clinic that answers all four in writing has thought about the case. One that answers only the first has quoted you for a stage, not a treatment.

Four versus six: what genuinely changes

Load distribution. More implants spread the forces of chewing across more points.

Tolerance of failure. If one implant fails in a six-implant arch, the remaining five may still support a bridge while the situation is resolved. In a four-implant arch, losing one is a more serious problem.

Bone requirement. More implants need more bone in more places. Where bone is limited, four well-placed implants may be a better plan than six poorly-placed ones — and the alternative to fewer implants is often grafting, which adds months.

Cost. Six implants cost more than four. That is the only part of the comparison that is straightforward, and it is the part most likely to drive an unqualified recommendation in either direction.

Note that the incentives point both ways. A clinic can upsell you to six. A clinic can also undersell you to four to win a price comparison. Neither number is the honest one by default; the honest one is the one that follows from your scan.

What a dentist needs before advising

• A CBCT scan, showing bone volume and density, the position of the sinus in the upper jaw and the inferior alveolar nerve in the lower
• An assessment of the teeth you still have and whether any are worth keeping
• Your bite, and what is happening in the opposing jaw
• Whether you grind or clench, which changes both the implant count and the material
• Your medical history — smoking, diabetes, bone medication
• Photographs, and ideally an in-person examination

Anybody proposing a specific number of implants from photographs alone is guessing. They may be guessing well, but the number is not yet a plan.

Risks and limitations worth knowing

• Implant failure, in a minority of cases. Establish in advance who bears the cost of replacement, and the return trip
• Cleaning is different. A fixed full-arch bridge cannot be cleaned like natural teeth. Specific tools and technique are needed, and inadequate cleaning leads to peri-implantitis
• Peri-implantitis around full-arch implants is difficult to treat
• The bridge will need maintenance. Screws loosen, acrylic wears, teeth can fracture off a bridge. This is normal and it is ongoing
• Speech and adaptation take time, particularly with an upper bridge
• It is not reversible. Remaining teeth are removed as part of the plan

The question underneath the question

Most people arriving at full-arch treatment are choosing between it and dentures, or between it and years of individual repairs. That comparison is worth making explicitly with a dentist — including cost over ten years, not on the day.

Full-arch implant treatment can be genuinely life-changing for someone who has spent years with a failing dentition. It is also the largest, least reversible and most expensive thing dentistry routinely offers. Both of those are true at once.

Questions worth asking any Istanbul clinic

1. Four or six for me, and what in my scan makes that the right number?
2. Is this price per jaw or for both jaws?
3. Are extractions included?
4. What material is the final bridge, and what is the temporary?
5. Is the final bridge in this price, and does it need a second trip?
6. Which implant system, and can components be sourced in my country?
7. What is your protocol if an implant fails to integrate — clinically and financially?
8. How am I expected to clean this, and who checks that I am doing it properly once I am home?

The short version

The number in the name is one decision out of about fifteen, and it is not the most important one.

Ask what the final bridge is made of, whether it is in the price, and when it is fitted. Those three answers separate a complete quotation from an opening figure far more reliably than four versus six ever will.