All-on-4 vs All-on-6: which one does your jaw need?
Six implants are not an upgraded version of four. They are a different answer to a different jaw. The number is decided by how much bone you have and where it sits, by which jaw is being rebuilt, and by how hard you bite, and it is read off a CBCT scan rather than chosen from a menu. A full arch on four implants costs 5,000–7,000 euro here and on six 6,500–9,000 euro, so the difference is real money, which is exactly why it should be an indication and not a preference.
What separates the two
| Four implants | Six implants | |
|---|---|---|
| Typical indication | Adequate bone in the front of the jaw, good bone quality, moderate bite force | Reduced bone height at the front, softer upper-jaw bone, heavy bite, a longer arch to support |
| Where the implants sit | Two upright at the front, two tilted at the back to catch solid bone | Load spread along the arch, so each implant carries less and no long unsupported end |
| The bridge above | Usually 10–12 teeth, with a short unsupported end behind the rear implant | 12–14 teeth with support closer to the back, so the free end is shorter or absent |
| If one implant is lost | The remaining three may not be enough to keep a fixed bridge; a rescue plan is needed | Five may still hold the bridge while the sixth site heals |
| Jaw it suits most often | Lower jaw, where bone is denser | Upper jaw, where bone is softer and the sinus limits height at the back |
| Price per arch | 5,000–7,000 euro | 6,500–9,000 euro |
Send us a panoramic X-ray and, if you have one, a CBCT file, and the dentist who will treat you will tell you which number your jaw supports and price that arch in writing before you book anything.
Bone comes first, and it is measured, not estimated
Both designs rely on one principle: put the implants where solid bone is, and use a rigid bridge to share the chewing load between them. In the lower jaw the bone in front of the mental nerve is usually dense and tall enough for two upright front implants, and the back ones can be tilted forward to pick up length without straying into the nerve. That geometry is what makes four workable in a lower jaw.
The upper jaw is a different structure. Bone there is more porous, the sinus floor drops down over the back teeth, and long-standing tooth loss thins the ridge from the outside in. Spreading the load across six implants is a way of compensating for bone that gives less grip per implant. This is the single most common reason we plan six above and four below in the same patient, and it is why a quote for “All-on-4, upper and lower” should be read carefully rather than assumed to be the efficient option.
Height and width are read in millimetres from the CBCT, per site, along with the position of the nerve and the sinus. A panoramic X-ray flattens the jaw into two dimensions and cannot give you any of that, which is why it is enough for a first opinion and not enough for a surgical plan.
Bite force and the span of the bridge
The second variable is what your jaw does all day. A heavy chewing pattern, or clenching and grinding at night, puts far more load through a full-arch bridge than an average bite does, and the load concentrates at the ends. On four implants the bridge extends a short distance behind the rear implant with nothing under it, and that overhang is the part that flexes. Lengthen it and stress rises steeply at the rear implant and in the bridge material itself.
Six implants shorten or remove that overhang. If you know you grind, if you have broken teeth or previous crowns in the past, or if you want a longer arch with molars rather than stopping at the premolars, the extra support is doing structural work rather than adding reassurance. We supply a night guard with every full-arch case and the written plan says so, because protecting the bridge at night is part of the treatment and not an accessory.
The myth that six is always safer
It is intuitive, and it is only sometimes true. Six implants in a jaw with poor bone at two of those six sites means two implants placed in bone that cannot hold them well, and an implant that fails to integrate is a delay, a second surgery and a site that then needs grafting. Crowding implants too close together also compromises the blood supply to the bone between them. In a lower jaw with good bone volume, four well-positioned implants in solid bone are a stronger construction than six mediocre ones, and they leave you a simpler mouth to clean, since every implant is another place plaque can accumulate around.
The defensible version of the argument is narrower and worth stating plainly: with six implants, losing one is less likely to cost you the fixed bridge. That is a real advantage and it is why we plan six when bone allows it and the bite demands it. It is not an argument for six in every mouth.
Cost, and what the gap actually buys
The difference between 5,000–7,000 euro and 6,500–9,000 euro per arch is two more implant fixtures, two more abutments, a longer surgical appointment and a bridge with more support points, all priced on the plan as separate lines. What it does not buy is a different grade of bridge or a different surgeon. If you are comparing a four-implant quote from one clinic with a six-implant quote from another, compare the material of the final bridge and the number of visits in each before you compare the totals, because those two variables move the price more than the implant count does. The full cost breakdown for a fixed arch sets out every line.
FAQ
Can I choose six implants even if four are enough?
You can ask, and if your bone genuinely supports six we will discuss it, but we will not place implants that the plan does not need. Two additional fixtures in sites that were not chosen on merit add surgical time, cost and two more surfaces to keep clean, for no measured gain in how the bridge performs. If four is what the CBCT indicates, the written plan says four and explains why in a sentence you can take to another dentist for a second view.
Is the same-day temporary bridge possible with both?
Usually yes. Both designs can be planned so that a temporary fixed bridge is fitted during the same visit as the surgery, so you do not leave Tirana without teeth. What decides it is the stability measured at placement rather than the number of implants. If any fixture is less stable than it should be, we say so on the day and the temporary is adjusted or delayed rather than loaded. Our page on All-on-4 dental implants sets out the visit plan in full.
Is there ever a case for more than six?
For most arches the answer is no, and the question is usually asked because more sounds safer rather than because a scan suggested it. Beyond six, the gain in load sharing falls away while the surgical time, the cost and the number of surfaces to clean all keep rising, and each additional site has to be good bone in its own right.
If I have All-on-4 now, can two more implants be added later?
Sometimes, and it is not a smooth upgrade. Adding implants to an integrated arch means new surgery in sites that have been unloaded for years, and the existing bridge either has to be modified to engage them or remade. It is a solution to a problem, usually a lost implant, rather than a planned path. If your bone and bite point to six, plan six at the start.
What if my upper and lower jaw need different numbers?
That is common and it is not an inconsistency in the plan. A lower arch on four and an upper arch on six is a frequent combination, because the two jaws have different bone. The plan prices each arch on its own line, so you can see what each is costing and decide to do one arch on one trip and the second later. Our page on All-on-6 explains the upper-jaw indication in more detail.
Upload your X-ray or CBCT to the quote form with a note of whether you grind your teeth and which arch concerns you more. The dentist who will treat you reads it, decides the number from the bone, and you receive the plan and the exact quote by e-mail within 24 hours.
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