Four implants will be enough for everyone – why the minimum sufficient number of supports does not work in biosystems

Four points of support on the jaw, in theory, allow you to install any structure. Also, in theory, you can kill a bear with your bare hands.

Before talking about biomechanics, I will note that in the interval between the beginning of retirement and death, your teeth will fall out. For IT professionals, this happens more often before retirement. Because you don’t have to work at night, eat pizza and endure. Soviet medicine offered you new teeth that sleep next to you in a glass. Modern medicine offers normal implants.

You, as any adequate patient, of course, want to install all this as quickly and cheaply as possible. Marketers have come up with everything a long time ago and called it “Teeth in one day”, aka All-on-4. This is a mathematically ideal design, which is an arch of a fixed prosthesis that replaces the entire jaw and is mounted with four screws. It costs very, very cheap, from 120 thousand rubles. Well, the truth is, you still need to remove all the remaining healthy teeth, otherwise no ideal is possible.

Of course, the ideal mathematical model is rather crooked for real biosystems. Actually, now I will tell you what is the difference between an excellent theory and the real world, and where exactly you, most likely, they will try to mislead, without saying something.

Advantages of the approach

All in all, the idea is great. The All-on-4 system has proven efficiency and comes in handy when you need teeth now, and it’s difficult with finances.

This is a very good method without expanding the readings. Indications – teeth for extraction all over the jaw, a certain state of the bone (rarely available to pensioners), good osseointegration later.

That is, cheap, cheerful, mass-produced and therefore even cheaper. Looks like a medical dream in terms of automation

Cons of the approach

If at least one out of four implants does not take root, then it is no longer possible to make a fixed structure. Osseointegration is always predicted approximately. Any surgery is a joint work of the surgeon and the patient’s body. The surgeon creates the conditions, and the body’s regenerative abilities are trying to do the main work. Conventionally, you have a 95% chance of engraftment of each individual implant. And for the structure to work, it is necessary that all four take root well. Three do not fit, the face will be distorted later.

The solution, of course, is simple – N + 2 redundancy, that is, installation on six implants (N + 1 is not suitable due to the axial symmetry of the structure).

Now let’s figure out more precisely what is “all in 4”

An implant is a small titanium screw with an external thread and an internal thread, which is installed in the jawbone and becomes the root part of the future tooth. Titanium takes root well, the body does not reject it, therefore such an implant is reliable and durable.

An implant is an attachment point for structures, a slot for integration with your jaw through its internal thread.

A crown is put on the implant, which becomes a new tooth.

This is how an installed crown (tooth) looks like on a titanium implant (root)

And so on the model

With the “all in 4” technology, four main implants are installed: two in the projection of the second teeth, and two more – at an angle so that the implant shaft comes out under the fifth and sixth teeth. And these four Atlanteans hold the entire jaw prosthesis. It looks like this:

Prosthetics of the upper and lower jaws on four implants

In order to form the chewing function, we need 12 teeth on the jaw – at least 12. That’s six on each side. With such a jaw prosthesis, four implants cope quite well and distribute the load quite well.

Historically, Swedish specialists from Nobel Biocare (manufacturer of implants) have funded the research work carried out by Portuguese professor Paulo Malo. The idea of ​​installing a prosthesis on only four implants was not new, but it was Malo who finally polished the technology and brought it to life perfectly, having carried out prosthetics using the All-on-4 system for the first time.

It is really possible to remove the remaining teeth and put implants in one day in some cases – when there was no bone resorption in the place for the implant, for example. Then the patient is given a temporary construction made of polymer, he leaves the office with a white smile and for the next three months he eats cereals, cutlets, mashed potatoes and in general any food that someone has already chewed for him. After four months, the temporary structure is changed to a permanent one. All this happens so quickly because there is no need to wait for the bone graft to integrate, since the patient does not undergo bone grafting at all. Accordingly, All-on-4 is a fairly simple rehabilitation due to the low volume of surgical intervention. Well, this all means a low price (relative to other methods of installing fixed dentures).

Method limitations

Suppose that in the place where the optimal geometry recommends placing the implant, there is no tooth for more than a week. Most likely, this means that the volume of bone tissue has decreased (resorption has occurred), and there, for example, bone augmentation is needed.

But much more often you need to look not at the jaw itself, but at the skeleton of the skull. And here comes such a thing as sinus lifting (bone grafting), and, as a rule, everyone is afraid of sinus lifting. Of course, there is an objective reason for this: bone grafting increases the cost of the operation at least twice. If we put four implants, then it can cost from 400 thousand. And if we put six implants and at the same time do two sinus lifts, then this can already cost from 800 thousand.

The complexity of the operation is low, and it can be done correctly by almost any surgeon whose arms grow out of the right place. Since 1964, everything has been done often and rather routinely. With sinus lift, bone build-up occurs in the area of ​​the maxillary sinuses, which are located in the upper jaw to the left and right of the nose. When a patient has a tooth removed, the bone is deprived of its load at the extraction site. Having lost the load, the bone begins to atrophy, and its loss occurs, because of which it begins to approach the maxillary sinus.

What bone resorption looks like

The whole thing is that there is negative pressure in the maxillary sinus – that is, it turns out that it is also pressing on the other side. Ultimately, due to this all-round crush, there is very little bone to place the implant. Ironically, there is often the most important and most decay-prone tooth – the sixth chewing tooth. And precisely in order for us to be able to deliver the sixth chewing tooth to the patient in this place, the maxillary sinus must be lifted with the help of sinus lifting – an increase in the volume of bone tissue. In this case, the bone graft is placed in the area where the blood supply is from four sides, so the procedure is very reliable.

How a bone graft increases bone volume

Now we come to the reason why sinus lifting and All-on-4 are incompatible: the temporary construction is placed on at least four implants. If we have a total of four implants planned and bone grafting has been done around one of them, then we will not be able to install a temporary non-removable structure on the remaining three implants. When we have six implants, four of them are usually in an area that can be loaded.

Another nuance that is usually overlooked is that the classic version of the “all in 4” system was supposed to have a zirconium bridge, but it just so happened that zirconium is expensive. Therefore, a plastic bridge is used on this construction, which is called a hybrid-titanium composite prosthesis. On a hybrid-titanium composite prosthesis, teeth are perfectly erased. As a result, it turns out that something will inevitably fall under this structure. But the essence of the prosthesis is that it is not removable for the patient – it will not be possible to thoroughly clean it on his own. Such a prosthesis will have to be replaced every five years. Of course, it’s not very difficult, but it is definitely very inconvenient. Here is an example of how you can cheerfully fly in for 3 million rubles and a couple of operations if the prosthesis is not changed on time.

Now let’s look at an example with a zirconium structure, which is more durable and does not need to be changed. The main risk here is already next in the risk model, this is a cleavage. It is much less likely. In the best case, the sixth tooth will chip, then we will rejoice and just polish it. But you may not be lucky, and the front tooth will chip. In this situation, there is simply no possibility of restoration. The prosthesis managed to live for several years in the patient’s mouth, and no one will take it back to work for restoration. The doctor will say: “Guys, this is not serious. Everything needs to be redone, organic components inevitably accumulated here. ” If you put such a prosthesis back into the oven at 800-900 degrees, you get a crematorium for bacteria, but everything will float. Therefore, the design of the prosthesis is best divided into parts, especially if the patient is young. This makes re-installation possible.

Practical advice

Let’s imagine that you asked me for advice: what kind of prosthetics should a mother do, she is 65 years old? I will answer that there is a variant of a prosthesis with six or eight implants. This gives us the opportunity to vary and shape the gums more comfortably. Naturally, such work will cost more. There is a variant of a prosthesis on four implants, it is also cool, but with its drawbacks – food will clog, and it is more difficult to restore it. If the bone is okay, it might be cheaper. You can even put a plastic one, which is even cheaper, but it will have to be changed in five to six years. Then it’s up to you to decide. We describe all the risks and all the outcomes in each choice, because this is our


What marketers are doing

Older people usually come for All-on-4. But it so happened that one of the advantages of this technology is determined by the mass, so manufacturers need to maintain a certain volume. Accordingly, their marketing influences the marketing of clinics, which in medicine always leads to an expansion of indications for intervention. From the point of view of evidence-based medicine in our bioethics, this is unacceptable, but not everyone adheres to the same views. For this reason, even young people are advised to remove all their teeth and have such a construction installed. This is a very incorrect and extremely dreary thing in medical practice.

“Teeth in one day: 120 thousand rubles per jaw!” – this is what you will see on billboards on the track and in contextual advertising. Why pay more when you can pay less? Well, then the patient gets a price reference.

Further, cheap structures are made from cheap materials using cheap technologies. What’s bad about it? This is often a poor quality product that has not passed clinical trials. In the best case, the implant simply will not take root, and the prosthesis will fall apart. In this regard, I adore the analogy with dumplings: if they cost 90 rubles per kilogram, then, probably, something is not quite right with the meat in them. So it is with the cost of implants. Operation planning is done with expensive devices and expensive software. Dentures are not stamped at the factory, but are made for each patient individually. The operation should be performed by an experienced maxillofacial surgeon. We will generally keep silent about such trifles as 30-year support of implants with accessories (here is more details) and correct diagnostics.

Further, these clinics spoil the market by the fact that at some point the patients understand from the experience of use what exactly they were supplied with. And they start to write a huge number of negative reviews. But this is not a bad technology, and therefore implants do not take root – and in most cases these are bad implants that were placed with bad hands.

In our clinic, the price bracket for the systems for which we are responsible with our reputation will be something like this:

  • 4 implants + plastic teeth: from 720,000 rubles.
  • 4 implants + zirconium teeth: from 1,300,000 rubles.
  • 6 implants + plastic teeth: from 875,000 rubles.
  • 6 implants + zirconium: from 1,430,000 rubles.

In the region, as I said, you can find from 120,000 rubles.

In defense of technology

It is an excellent technology, fast and inexpensive, with clinically proven efficacy. In many cases, it can be safely offered to the patient, and he will be able to live happily ever after with new teeth. Next is the question of the risks of disturbing loads, chips and contamination with bacteria. All these risks can be substantially minimized by choosing six support points and normal materials and systems.

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