Atrophy of bone tissue is the number one problem that becomes an obstacle to dental implantation. But with one reservation - according to the classical method, since today a number of dentists offer patients methods of prosthetics on implants without increasing the jaw bone. We are talking about protocols All-on-4 and All-on-6.
Literally, their name translates as "all on four" and "all on six." The methods are a kind of alternative to removable prosthetics with full edentulous or in cases when it is necessary to remove a part of living teeth in poor condition.
The All-on-4 technology is a patented development of the American-Swiss company Nobel, which has been producing dental implants of the same name for more than half a century. Prosthetics on six implants are, in fact, the next generation, since the development of this technique took into account the drawbacks and shortcomings of the “all four” technology.
Both methods are used in the presence of atrophied bone tissue and imply an immediate load of the prosthesis. Only now they are found not in every clinic.
Next, we will try to understand the pros and cons of each method and find out why they are not too common in our country - because of the lack of skills from implantologists, a short life, or there are other disadvantages?
What is the essence of technology All-on-4?
As mentioned earlier, this development is owned by Nobel, which was the first in the world to cooperate with the developer of dental implants (Dr. Brannemark) and launched products into mass production.
It is interesting
The concept of All-on-4 for the first time in practice was applied in 1998 by the Portuguese implantologist Paulo Malo. First, the doctor worked in isolation, but later his development was acquired by Nobel, which in 2004 introduced this treatment concept to the market.
The concept of prosthetics on four implants is more common abroad (in Europe and the USA) than in our country. This is explained by the fact that the implantologist must necessarily undergo training and receive a certificate from Nobel for the right to work with this protocol.
It is worth noting that Nobel products are one of the most expensive, and this is one of the reasons why doctors are not in a hurry to receive the appropriate certificates - there will simply be a small demand for implants, and the implantologists themselves often do not have the opportunity to undergo appropriate, very expensive, training.
So, the fundamental differences between the All-on-4 prosthetic technology are as follows:
- Only 4 dental implants are used for prosthetics of the complete dentition;
- 2 implants are fixed at an angle in the lateral areas (between the fifth and sixth teeth), 2 others - vertically in place of the front teeth;
- The prosthesis is installed instantly, that is, not every other day, not an hour later, but immediately after the implants are implanted;
- Implantation in the implementation of All-on-4 technology is performed with weak or moderate bone resorption, as well as with a sufficient amount of bone tissue;
- Implants are classic two-part constructions, but a multiunit abutment (angular) is used, designed to be used precisely at a certain inclination of the implants. That is, the abutment itself after attachment acquires a strictly vertical position;
- At all stages of treatment using computer 3D modeling.
Now we will consider each item in more detail - both in terms of the advantages and disadvantages that have been identified by implantologists who practice this system.
Types of implants and features of their installation
When using the All-on-4 prosthetic technique, two-part implants with a screw design are used - these are, in fact, classical root-shaped models created from pure titanium and equipped with a special porous TiUnite coating (present on all models of implants of this brand). It is a rough layer of titanium oxide with a high content of phosphorus, which significantly speeds up the process of osseointegration, that is, the accretion of bone and implant.
Such implants are also installed in the traditional way (patchwork) - after the introduction of anesthesia, the gums are cut, exfoliated from the bone tissue, a bed under the implant is formed inside the bone (sawed out with the aid of boron), and after placement of the implant the gum is sutured.
The concept implies the use of only 4 implants (with the classical approach they require at least 8-10 per row).Two are mounted in the area of the front teeth, the other two - in the lateral section. And they are fixed at an angle of up to 45º.
Important!
Inclined installation of lateral implants makes possible their implantation, bypassing important anatomical structures, for example, the maxillary nerves, the nasal sinuses. In addition, it is possible to more uniformly place the implants on the alveolar ridge and optimally distribute the load on them. The inclination of the side "screws" also allows you to increase the contact area between the implant and the bone, thereby creating a full support for the prosthesis.
The abutment is fixed on top of the implant. For inclined implants, inclined abutments (multi-unit) are also selected. Due to this, the position of the tops of the implants above the gum is aligned, and the prosthesis is fixed strictly straight, without disturbing the occlusion and bite of the patient.
Is it really not necessary to build a bone when using prosthetics using All-on-4 technology?
The All-on-4 concept is used for mild to moderate bone tissue atrophy:
- On the upper jaw - at least 5 mm in width and 10 mm in height;
- On the lower jaw - at least 5 mm in width and 8 mm in height.
The oblique position of the implants allows you to choose places with a thicker bone of sufficient volume, so treatment can be carried out with bone tissue atrophy.
An important feature of the All-on-4 prosthetics method is that its implementation is justified only with a mild degree of atrophy of the jaw bone, but not with its pronounced resorption.
Opinion of the practicing dentist:
“All-on-four is undoubtedly one of the best technologies designed for patients with adentia. But only moderate and mild. The concept suggests that the degree of primary fixation of implants must be at least 35 Newtons, which is impossible to achieve in the presence of pronounced bone atrophy. I repeatedly had to observe the work of my colleagues, when the lateral implants were shifted slightly forward or backward relative to the place that is recommended to choose according to the protocol (precisely because of the lack of space). After a few years, this led to a complete collapse of the entire system, since part of the bone simply continued to atrophy due to lack of load. ”
Another point that concerns the state of the bone tissue is the implantation at the same time as the removal of diseased teeth, which are preserved in the row. In the classical approach, it takes some time (usually 3-4 months) for the bone tissue to recover, and only after that it is possible to perform implantation.With the All-on-4 dental prosthetics technology, the situation is, in principle, similar, only the protocol developer proposes to install implants next to the well, without waiting for a full tissue repair.
Prosthetic capabilities
According to the original All-on-4 protocol, the fixed acrylic bridge is installed immediately, simultaneously with the implants. It is installed for a period of several months (about six months) - that is, you need to wear it until the implants merge with the bone.
The option of relocating a prosthetic detachable prosthesis that was previously worn by the patient is also allowed.
Important!
The patient must be prepared for the fact that the prosthesis will be made with an acrylic base - a kind of artificial gingiva. Its use is explained by the fact that it is necessary to “cover up” the defects of one's own mucous membrane, since, due to the long absence of teeth, it has a very unaesthetic appearance. It is expensive and difficult from the point of view of patient rehabilitation to perform plastic surgery on the whole row. Therefore, it is proposed such an option.
The results of prosthetics using All-on-4 technology look quite aesthetic - the examples are shown in the following photos.
Example 1, before treatment:
After treatment:
Example 2, photo before treatment:
After:
Instant prosthetics (that is, immediately after the implants are implanted) pursues several goals simultaneously:
- The All-on-4 prosthesis stabilizes implants. Between themselves, they are united by a metal beam, which ensures their fixation in a certain position. This is possible precisely in the case of the absence of all teeth (if you load only one implant, then it will shift under pressure);
- The prosthesis provides the load on the bone. The jaw bone of a person must receive pressure - this is physiological, because it is through it that the cells are fed. When the chewing load is restored inside the bone, the natural processes are activated, and the regeneration is faster (that is, the volume of the bone is gradually restored);
- The prosthesis returns the patient aesthetics and the ability to fully eat.
Restrictions to the first month after implantation - in a gradual increase in the chewing load.
Expert commentary:
“According to the original All-on-4 prosthetic technique, the prosthesis is installed on the same day that the implants are implanted.From the point of view of the patient, this is great news, because you leave the doctor’s office with new teeth. But in practice, the installation of the prosthesis is better to move for a couple of days and install the crowns at least a day after the operation. Indeed, after the installation of implants, stitches are placed and the gums are injured. It takes some time to rehabilitate them - otherwise there is pain, and there is also a high risk of inflammation of the mucous membranes. ”
Process simulation
Nobel company is famous for its innovative approach to treatment. After the initial consultation with the doctor, medical or cone-beam tomography is performed. The obtained data is downloaded to a computer, and with the help of special software (Nobel Guide), the whole treatment process is simulated in a three-dimensional, three-dimensional version.
The doctor creates a virtual model of the jaw, sets the volume of the bone, the location of all the important anatomical structures. The program helps to choose a place for implantation, and later surgical templates are developed that help to install the “screws” according to the plan, without shifting even a fraction of a millimeter.
Accurate treatment planning eliminates “human” errors.In addition, the patient himself can evaluate the final result of the prosthesis.
As for the cost of treatment ...
But the cost of implantation All-on-4 is one of its main drawbacks. The cost of prosthetics is quite high and reaches 400 thousand rubles for the restoration of one dentition.
This is explained, firstly, by the high cost of the Nobel implants themselves (after all, the company invests heavily in research and the introduction of unique technologies), and secondly, by the work of the doctors themselves, who need to undergo expensive training. And, thirdly, high-tech equipment, which is used in the planning and implementation of treatment.
Are there any downsides?
If the “all-four” implantation is carried out in strict accordance with the original treatment protocol, then it has very few flaws.
The first is the high likelihood of inflammation of the mucous membranes, since the prostheses in the original technique are fixed on the same day as the implants are installed. For the patient, on the one hand, this is a plus, because at the same moment aesthetics are restored. However, in practice, injured gums react with inflammation. The problem is solved by fixing the prosthesis for 2-3 days after surgery.
In addition, experts note that when the implants volume of the jawbone of four implants is not enough, the bone does not receive the proper load and continues to atrophy, resulting in frequent relocation of the prosthesis and possibly a shift of the implants.
Another disadvantage of All-on-4 prosthetics is also associated with bone tissue. To install implants in the bone tissue, a bed is formed with the help of boron. At the same time, a part of the sawed own bone is extracted from the hole, and in fact, in conditions of atrophy, the patient’s own bone material is, in fact, “worth its weight in gold”. For comparison: with the All-on-6 technology, which will be discussed further, the implants are screwed into the bone in a compression manner, and bone loss does not occur - on the contrary, it is compacted around the implant thread, which contributes to its better fixation.
Can I perform All-on-4 prosthetics on other implants?
The technology of prosthetics "all on four" is trying to repeat many other companies. But really, only Nobel has clinically proven results in the long term (besides, it has a patent for this protocol).Therefore, if you want to undergo treatment using the original technology, then you need to look for doctors who have the appropriate certificates and practical skills in this area.
On the other hand, the use of implants of other brands can significantly reduce the cost of treatment - up to 200 thousand rubles. But in this case, preference is given to structures that have also proven themselves in the market (for example, Osstem, BioHorizons, Ankylos, Alpha Dent).
Patient's review of All-on-4 prosthetics:
“I’m 64, wore removable dentures for a long time, but it’s tired. I am quite an active person, I travel a lot, I love cooking. I applied to several clinics, but the period of treatment per year (!!!) is unacceptable for me. Found a variant of prosthetics all four. Carefully studied. Company Nobel inspires confidence. Installed implants quickly, the bone was planted at the same time. The first months were nutritional restrictions, but after six months, I replaced the prostheses with dioxide and enjoy life. The operation was carried out about 3 years ago and to this day my teeth make me happy, there are no complaints. ”
Ivan Semenovich, Moscow
About the All-on-6 Prosthetic Method
The concept of prosthetics All-on-6 was developed by practitioners, who took as a basis the practice of applying technology on four implants and took into account the experience of using basal implantation. The protocol is carried out using six implants.
Unlike All-on-4, the indications for treatment were expanded: prosthetics are performed with moderate bone tissue atrophy, as well as with periodontitis, periodontal disease, or osteomyelitis of the jaw. Smoking is not a contraindication.
In general, the two technologies are similar - the similarities and differences of the mentioned protocols will be presented below.
To begin, let us designate the distinctive features of the All-on-6 prosthesis protocol:
- 6 dental implants are used for prosthetics of the complete dentition (4 implants are fixed at an angle in the lateral areas, and 2 others - vertically in the frontal zone);
- The prosthesis is installed 2-3 days after implantation;
- All-on-6 implantation is performed with moderate or severe bone resorption;
- Implants - one-piece with an abutment, the angle of which is selected individually and can be adjusted after the “screws” are implanted;
- Implant placement is possible at the same time as teeth are removed, and the “screws” are installed in the same hole;
- The All-on-6 prosthetic technology is a more cost-effective solution than the classic implantation and All-on-4 in the original technique.
Types of implants and features of their installation
When prosthetics using the All-on-6 method, fundamentally different models of implants are used, rather than using All-on-4 technology:
- Single-part implants, that is, the abutment and intraosseous part is a single whole. After installation, the abutment bends to align the bite and the position of the prosthesis;
- Implants are fixed in a minimally invasive way - they are literally screwed into the bone, while the gum does not flake, the stitches after the operation do not overlap. This means that the patient recovers faster;
- Implants are placed at an angle. As with the use of technology “all on four”, this approach allows you to bypass the most atrophied areas of the bone, choosing the most durable sections of it, and not to hurt the nerves and nasal sinuses.
Is it really not necessary to build a bone with All-on-6 prosthetics?
The designs of the implants used are designed in such a wayso that their fixation is possible not only in the alveolar (spongy) part of the jaw bone, but also in the deeper parts. These are the basal layer, the cortical plate or the shell of the bone, as well as the zygomatic bone and the buttresses of the jaw (lines of force).
On a note
The most "soft" layer of bone - central (spongy). At 90% it consists of capillaries. In the absence of teeth, the metabolic processes in the bone stop, which means that it is the spongy part that suffers first of all, noticeably shrinking in volume. The remaining sections consist of bony septa — they are more durable, have fewer capillaries in them or they are completely absent, and here atrophy is not so pronounced. That is why implants for immediate load will involve these layers in the first place.
Due to the fact that implants are fixed in dense parts of the bone, the strength of their primary stability is 80-100 newtons, whereas with classical implantation this figure varies in the region of 30-40 newtons.
All this suggests that it is not necessary to build up the bone during prosthetics with the All-on-6 method - implants will be fixed in the available volume.
What are the similarities of the two technologies?
The main similarity of the two methods is in the possibility of immediate loading with the prosthesis. And the goals of the instant installation of crowns are completely identical - to load the bone, to restore the aesthetics and functionality of the dentition and to stabilize the installed implants. Prostheses in both cases are created with an artificial gum, which will hide the uneven contour of the natural mucosa.
The photo below shows an example of how dentures may look when using both technologies - All-on-4 and All-on-6:
Patient's review of prosthetics on six implants:
“I doubted for a long time when choosing this method. It was embarrassing that the denture would have to be changed over time and that it has a plastic gum. After all, it turns out the same removable denture! Doctors showed pictures, but one thing is a photo, and the other is real life. Long thought, but decided, as the price is very attractive. As a result, after the implants were installed, there was practically no pain at all, only mild discomfort, as after a tooth extraction. The prostheses were placed on day 3, it did not take long to get used to them, since they are much more comfortable than removable ones! While I wear 2.5 years, periodically I go to the relocation of prostheses.But they look quite decent, while I’m changing and I don’t think! ”
Margarita P., Moscow
When planning dental prosthetics using the All-on-6 method, computer modeling is also used - modern technologies allow to thoroughly work through the entire treatment process in order to avoid inaccuracies in the installation of implants.
A few words about pricing
For All-on-6 prosthetics, implants from brands such as Oneway are used.
Biomed, Osstem, Noris Medical, Bio Horizons - in the product line of these companies there are models specifically designed for immediate load. These firms have been around for a long time, which means that there are proven in practice data from successfully performed operations with the results of implant engraftment in the long term.
Companies produce products of the middle price segment, so the cost of treatment is very affordable - from 200 to 300 thousand rubles for a complete prosthetic repair of one dentition.
What are the disadvantages of technology All-on-6
The All-on-6 prosthetics technology appeared later than the All-on-4, therefore, its development took into account the main drawbacks of the protocol.
However, there are also disadvantages - prosthetics on six implants belongs to the group of technologies with immediate load, and a very limited number of implantologists work with them in our country.Firstly, you need to go through very expensive training abroad, and secondly, you need to be a professional in your field and have knowledge of not only implantology, but also maxillofacial surgery and orthopedics.
On a note
This method places high demands on the skill of the attending physician: it must be a maxillofacial surgeon, orthopedist and be proficient in working with software for 3D modeling of the treatment process. He must have thorough knowledge of the structure and operation of the maxillary system (not only do you need to install implants in a narrow and thin bone, you also need to correctly calculate the load on them and adapt the prosthesis so that it will last several decades without breakage and with comfort for the patient ).
Specialists working with technology All-on-6, must obtain the appropriate certificate, which gives permission to work on the protocol immediate load.
If you compare technology, which method is preferable?
To summarize, the similarities and differences between the two technologies are presented in detail in the table below:
All-on-4 | All-on-6 | Classical dental implantation | |
Indications | Complete adentia and partial bone loss | Complete adentia and moderate bone loss | Lack of any number of teeth |
Periodontal inflammatory processes | Not carried out or with restrictions | Unlimited | Not carried out or with restrictions |
Indications for bone tissue | Sufficient quantity or slight loss of volume. | The average degree of loss | A sufficient amount (in case of volume violations bone grafting is performed) |
Smoking | Implantation is not carried out or with restrictions. | Held | Not carried out or with restrictions |
Number of implants required to restore the dentition | 4 things. | 6 pieces | 8-14 pcs. |
Type of implants | Classic two-part inclined multi-unit abutments for screw attachment of the prosthesis | One-piece - the implant is connected to the angled abutment for screw attachment of the prosthesis | Classic two-part abutments with separate abutments |
Where are mounted and how implants are installed | Front - upright, side - tilted, spongy layer is involved | Front - upright, side - tilted. All layers of bone tissue are involved, as well as buttresses and zygomatic bone. | Strictly upright in the spongy layer |
The invasiveness of the installation of implants | High - tissue incisions are made, gums exfoliate | Low - implants are installed by the puncture method | High - tissue incisions are made, gums exfoliate |
Prosthetics | Immediately after the installation of implants | In 2-3 days | A permanent denture is installed on average in half a year, and at this time a removable denture is attached. |
Cost (prices for 1 jaw are given) | From 180 thousand rubles - cheap models of implants; from 400 thousand rubles - on Nobel implants | From 200 thousand rubles | From 500 thousand rubles |
To summarize, the prosthesis All-on-6 goes one step ahead (or rather, two steps, judging by the number of implants to be installed) compared to the technology, where only four “screws” are used.
However, the use of each technique is justified in certain conditions of the jawbone: All-on-6 is not necessary to apply with a sufficient amount of bone tissue, and All-on-4, on the contrary, is ineffective at low quality of the bone structure. Therefore, only the attending physician should choose the method of prosthetics based on the results of a clinical and computer examination of the oral cavity and jaw bone.
Immediate load prosthetics with All-on-6 technology