There is a very important principle in implantology, which reads as follows: "From the crown to the implant". This means that the doctor is primarily obliged to plan the orthopedic construction on the implant (crown or prosthesis), and only then think about the type of implant or the choice of surgical technique for its installation.
You can not imagine - how many in the installation of the crown on the implant lies in the subtle points that doctors often neglect. Already after only 1 year after surgery, these errors can lead not only to unsatisfactory gum aesthetics around the neck of the implant, but also to the development of inflammation and even rejection of the implant.
Implant crown with cement and screw types of fixation -
The most important points -
- selection of screw or cement fixation of the crown on the implant,
- correct removal of casts
- the start of prosthetics,
+ we will list the main mistakes of doctors during prosthetics.
Important: unfortunately, when you start going to consultations, you will see that 90% of implantologists will try to screw in implants to you faster (to get money immediately), without going into long thoughts about the aesthetics of the gums around the implant six months or a year after prosthetics. This article is written for patients and will allow you to objectively evaluate the professionalism of the doctor’s approach to your problem.
1. Crowns on implants: which ones are better
Implants are mainly installed on metal ceramics, or metal-free ceramics made of zirconium dioxide. Rarely do crowns made of metal, which are cheaper, but still not the best and lasting solution.
In order to fix the crown on the implant, the doctor will first need to install a special adapter in the implant, called an abutment (Figure 3-6). Its lower part is immersed in the implant body, and the upper part protruding above the implant looks like a stump of a tooth ground under a crown (the only exception is one-stage implants, the design of which already assumes the presence of a fixed abutment).
The scheme of prosthetics on the implant and abutment variants -
Metal-ceramic crown on the implant -
Metal-ceramic crown on the implant is a reliable and quite aesthetic solution (Fig.7-9). After the implant's engraftment stage is completed, as well as the stage of gingival contour formation, a titanium abutment is inserted into the implant, and jaw casts are taken with it. According to these impressions in the dental laboratory, the technician will make your crown, which will have a metal frame lined with a ceramic mass on the outside.
With this type of crowns, abutments made of titanium are used (Fig. 4). They can be standard and individual. In some cases, we hear that some doctors suggest patients to make an abutment of CSC (cobalt-chrome alloy), but it is not recommended to agree to this, because There is a higher risk of such an abutment breaking. If such a breakdown occurs, the entire implant will only be removed.
Prosthetics by metal ceramics on an implant -
- Metal-ceramic crown on the implant: the price, taking into account the cost of the abutment, will be in the range from 15,000 to 25,000 rubles (see the detailed prices for the types of implants below).
Important: there are often situations (for example, with a low height of the crowns of the teeth) when it is impossible to use the traditional scheme "implant - removable abutment - crown". In this case, a good doctor will propose a solution when the metal frame of the metal-ceramic crown (on which the ceramic mass will then be applied) and the abutment will be a molded whole. Such work is very difficult and requires high qualification.
Most often, such solutions are offered to patients again from cobalt-chrome alloy (CX), however, it is not worth accepting. It is optimal to make such a construction only of titanium, for example, by milling. If the dental laboratory of the clinic (which you turned to) does not have the necessary equipment, then you can insist that they order production in another laboratory.
Ceramic crown on the implant -
Ceramic implant crown is made of such material as zirconia. This material is the color and transparency of the most natural enamel of the teeth, so it allows you to make artificial crowns as similar to their teeth. Metal-free ceramic crowns are fixed to abutments made either entirely from zirconia or from a combination of zirconia and metal (hybrid abutment).
The use of titanium abutments (intended for metal-ceramic crowns) is unacceptable here, because The abutment metal will shine through the translucent ceramic mass of the crown, giving it a gray, lifeless color. In Figure 10-12 - you can see the appearance of a ceramic abutment fixed on the implant - with the subsequent installation of a zirconia crown.
Prosthetics on implant ceramics -
- Ceramic crown on the implant: the cost, taking into account the cost of the abutment, will average from 25,000 to 35,000 rubles (see detailed prices for the types of implants below). The minus of these crowns is slightly higher than the frequency of chipping of the ceramic mass compared to metal-ceramic crowns.
How to choose between ceramics and metal ceramics -
Crowns on implants: which ones are better ... ceramics or metal ceramics you ask ... Metal ceramics will undoubtedly be cheaper and also have less risk of chipping the ceramic mass. For chewing teeth, we recommend doing exactly metal ceramics. However, if you need to make a front tooth, then the choice will depend on the transparency of the enamel of your neighboring teeth. With high transparency, it is worth making a ceramic crown, with a small transparency - you can stop the choice on metal-ceramic.
Alternatives to fixed prosthetics -
Fixed prosthetics with implants, of course, is the gold standard to strive for. However, unfortunately, not all patients can afford fixed structures, especially when virtually all teeth are missing. For such cases, there are also options for conditionally removable prostheses on 2-3x implants, the use of which is much more comfortable than traditional prostheses made of plastic or nylon.
2. Types of fixing crowns on implants -
There is a cement and screw types of fixation of the crown to the implant. Each type has its own indications, as well as pros and cons. Below we summarize all the information on choosing the optimal type of fixation.
Features of cement fixation -
The procedure is as follows ... The abutment chosen by the dentist is inserted into the body of the implant and screwed to it with a special screw (there is a through vertical hole for such a screw in the body of the abutment). A fixed abutment is a stump of a tooth ground under the crown. Only after that the made crown is fixed on the abutment with the help of special cement, which has depreciation properties (Fig. 13).
Conditions under which cement fixation is permissible -
- The height of the upper part of the abutment (protruding above the neck of the implant) must be at least 5 mm,
- the height of the attached gum around the implant (this is the gum that is immobile due to the solid adhesion to the periosteum) is at least 3-4 mm,
- the thickness of the bone walls around the neck of the implant must be at least 2-2.5 mm,
- the ratio of the height of the artificial crown and the height of the implant body must be no less than 1: 1.5,
- the correct position of the teeth antagonists.
Advantages of cement fixation -
This plus is only one, and it lies in the convenience and ease of work for the doctor and dental technician. However, cement fixation is unacceptable under the conditions described below in the indications for screw fixation.
Minuses -You should understand that with cement fixation, it will not be possible to remove the crown from the implant, and then put it in place. This may need to be done in some situations. The crown can only be cut, which then requires a complete replacement of the abutment and the crown (or a bridge of several crowns).
Features of screw fixing -
The fixation procedure is as follows ... The crown is connected to the abutment outside the oral cavity, after which this prefabricated structure is inserted into the implant. The crown and abutment have a through vertical hole into which a screw is then inserted, screwing them to the implant. The hole remaining on the chewing surface of the crown is sealed with a special composite material (Figure 16-18).
Indications for screw fixation -
- if bone grafting was performed (simultaneously with the implant installation),
- when the size of the attached gingiva around the implant is less than 2-3 mm,
- when gingival thickness is 2 mm or less,
- bone thickness around the neck of the implant is 2 mm or less,
- when fixing a temporary plastic crown,
- if the crown was made with an “artificial gum”,
- with a low clinical height of crowns,
- in the manufacture of the bridge on a large number of implants (4-5 or more).
Positive side of screw fixation -
The most important thing is that she forgives the mistakes of incompetent surgeons, implantologists, and allows them to correct after the fact. For example, many doctors do not bother when they see in the place of future implantation a small thickness of the gum or a small size of the attached gingiva. Although all this will inevitably lead (within six months or a year after prosthetics) - to the resorption of the bone around the implant and the gum recession. Not to mention the fact that all this also increases the risk of periimplantitis.
Therefore, a normal implant surgeon always recommends that the patient correct these deficiencies with additional intervention even before the prosthesis: either at the stage of implant installation, or at the stage of gingival contour formation. For this, transplantation of a mucous flap from the sky, split flaps, etc. is used. But, if all this is not done in advance (including for financial reasons, depending on the patient himself), then the screw fixation is a magic wand, which will allow in a certain amount to later correct the problems that have arisen.
Negative side screw fixation -
- First of all - there will be a hole on the chewing surface of the crown (a screw is inserted through it that screws the abutment with the crown to the implant). This hole is closed with a light composite, and this can only be noticeable to the doctor, but not to those around him.
- Secondly - over time, the screw may loosen and then a small mobility of the crown and abutment will appear. If the patient, noticing this, does not consult a doctor, then inflammation will gradually develop around the implant (periimplantitis).
- Thirdly - the most dangerous complication is that if the patient ignored the appearance of mobility of the crown, a screw fracture could occur. It is impossible to remove the screw fragment from the implant body, which leads to the need to remove the entire implant and a new installation operation.
What type of fixation is best for the patient?
Screw fixing of crowns on implants is by far the safest and most secure type of fixation for the patient. Even if the screw loosens, it is replaced very quickly. To do this, the doctor will unseal the hole above the screw and unscrew the last one, replacing the previously used screw with a new one. Especially this fixation option is recommended for implantation in the aesthetic zone and / or for prosthetics with a bridge-like prosthesis on several implants at once.
If you suddenly feel that the crown is loose on the implant (believe me, you cannot fail to notice it), then you will need to go to the clinic, where you have been implanted, preferably, but if this is not possible, then you can change the screw in principle clinic (the main thing to remember is the manufacturer of the implant you installed).
Screw implant fixation: video
3. Removing casts for making crowns -
There are 2 methods of taking impressions, which are used when you need to make artificial crowns on implants -
- closed spoon method
- open spoon method.
We will not explain in detail their difference, because The article is written for patients, and there will be a lot of complex technical details in the explanation. The method of "closed spoon" is only suitable for single implants or two implants that are installed as parallel as possible to each other. If you want to reduce the risk that the crown / crowns will be "not very" - insist on the following method for taking impressions.
The method of "open spoon" is more complicated, it is much more accurate. Should be used when there are several implants and / or they are located even at a small angle relative to each other (and this is always the case). This method can not be applied only in 1 case: when the crown should be made on the implant installed at the end of the dentition, and at the same time the patient has a narrow mouth opening.
Terms of manufacturing the crown -
installation of the crown on the implant takes an average of 2-4 weeks. As a rule, 1-2 weeks are spent on ordering and waiting for suppliers of the necessary types of abutments (if they are not available). And about 1-2 weeks will be spent on making the crown in the dental-technical laboratory.
4. Terms of prosthetics -
The implant crown can be fixed at completely different times after the surgical implantation stage, which will depend on the implantation technique. In implantology, there is a special term "load on the implant." The load on the implant occurs precisely at the moment when the fixation of the crown. There are the following permissible types of load (terms of prosthetics) -
- immediate load (immediately after surgery or in the first 72 hours),
- early load (within 4-6 weeks),
- late load (within 3-6 months).
Planning the time of prosthetics is carried out by the doctor at the planning stage of the implant installation operation. First of all, these periods will depend on the bone density at the site of implantation and the concomitant somatic status of the patient. The safest late load is the most safe, and it still shows the highest survival rates of implants (especially for patients at risk, for example, smokers).
Implantation techniques and prosthetic timing -
- Full immediate load on the implant is most often given when applying the basal implantation technique (using the basal implants). In most cases, crowns, fixed immediately after surgery, the doctor removes from the occlusion, so that they do not have a significant load.
There are also methods for immediate implantation, in which a temporary plastic crown is installed on the implant immediately after the operation. This crown is removed from the bite, so that the implant does not experience a chewing load. However, such an immediate prosthesis is indicated only for a small number of patients.
- One- and two-stage implantation techniques -
these are the so-called classical implantation techniques, in which the late load on the implant is mainly used, i.e. prosthetics is carried out in a period of 3 to 6 months. The final duration of the period of osseointegration (implantation of the implant) will depend on the bone density, whether the bone tissue was replanted, the patient's health status ...
Early load on the implant in terms of 4-6 weeks is applied less frequently. This requires good bone density, no need for bone grafting or sinus lifting, no burdened somatic status. When planning an early load, it is also advisable to use models of implants that have an ultra-hydrophilic surface, which allows to accelerate the implant osseointegration.
How to choose between implants from different manufacturers -
On what characteristics the implants of different manufacturers differ from each other, what implants have ultra-hydrophilic surfaces, whether there are high-quality inexpensive implants - read the article: "How to choose the type of dental implant correctly"
Implant crown: price for 2019
How much a crown costs on an implant - the cost will depend on the type of crown and the corresponding abutment. For example, it can be metal-ceramic (with an abutment of titanium), or be made of ceramics (zirconium dioxide). In the latter case, the abutment should be like the crown - also ceramic.
Below we analyzed the cost of prosthetics on implants in clinics of the middle price category and economy class. Metal-ceramic crown on the implant - the price starts from 15 000 - 20 000 rubles per crown (and this price already includes a metal abutment of titanium), and above. If we are talking about metal-free ceramic crowns, then a zirconia crown together with a zirconium abutment will cost, on average, from 25,000 to 35,000 rubles (the exact price depends on the type of abutment and the manufacturer of the implant).
How much is a crown on a turnkey implant -
The prices below are given taking into account the cost of not only a metal-ceramic or ceramic crown (with the appropriate type of abutment), but also the surgical operation of the installation of the 1st implant. First, we give the cost of economy class implants, and then - premium segment implants.
- The cost of the crown on the implant AlphaBio® (Israel) -
→ with a metal-ceramic crown - from 35,000 rubles.
→ with a zirconia crown - from 50,000 rubles.
- The cost of the crown on the implant MIS® (Israel) -
→ with a metal-ceramic crown - from 35,000 rubles.
→ with a zirconia crown - from 50,000 rubles.
- The cost of the crown on the implant Osstem® (Korea) -
→ with a metal-ceramic crown - from 40,000 rubles.
→ with a zirconia crown - from 50,000 rubles.
Cost of premium implant models -
- The cost of the crown on the implant Straumann® (Switzerland) -→ with a metal-ceramic crown - from 80,000 rubles.
→ with a zirconium dioxide crown - from 90,000 rubles.
- The cost of the crown on the implant AstraTech® (Sweden) -
→ with a metal-ceramic crown - from 70,000 rubles.
→ with a zirconium crown - from 90,000 rubles.
- The cost of the crown on the implant NobelBiocare® (Switzerland) -
→ with a metal-ceramic crown - from 90,000 rubles.
→ with a zirconia crown - from 100,000 rubles.
→ Fixed prosthetics of the edentulous jaw with a bridge prosthesis according to the All-on-4 protocol - from 280,000 rubles. for 1 jaw.
The cost of fixed prosthetics in the absence of teeth -
If you do not have teeth in the jaw completely, then this is not a contraindication to fixed prosthetics. Modern methods of single-stage implantation, for example: the All-on-4 technique or the basal implantation technique - allow you to get a non-removable bridge just 1-3 days after surgery.
- Fixed bridge in the absence of teeth -→ on 4 implants Osstem (Korea) - from 150,000 rubles.
→ on 6 Osstem implants (Korea) - 230,000 rubles.
→ on basal implants ROOTT (Switzerland) - 290,000 rubles.
Clinical case studies -
Below we give 2 examples of prosthetics with crowns on implants.
1) Clinical case number 1 -
(prosthetics of the upper jaw with metal-ceramic crowns on implants using titanium abutments and cement-type fixation) ...
2) Clinical case number 2 -
(Prosthetics of the maxillary lateral incisor on the Straumann implant, using ceramic abutment and cement-type fixation) ...
The main mistakes of the doctor during prosthetics -
The success of the operation and the qualitative osseointegration of the implant to the bone can be easily crossed out with errors during prosthetics. If there is no sign of bone resorption around the implant neck at the end of the implant engraftment period, but excessive bone resorption started right after the prosthesis, this means that it is not the implant surgeon who is to blame for this, but the orthopedic surgeon (prosthetist ).
The main mistakes of the doctor at the stage of prosthetics ...
- The edges of the crown badly fitted to the neck of the implant -
As a result, trauma and inflammation of the soft tissues of the gums occurs around the implant, leading to bone resorption and gingival recession around the neck of the implant.
- Wrong ratio of crown height to implant length -
if this ratio is not 1: 1.5, but 1: 1.3, then wait for the bone resorption and gum recession around the implant neck.
- The crown is much wider than the diameter of the implant -
here also wait for bone resorption and gum recession around the implant neck. This is typical for implantation in the region of the chewing teeth (molars), when it is impossible to install implants of large diameter. In theory, in this case, the doctor would consciously have to reduce the size of the crowns of molars to the size of premolars.
- The delay of food under the bridge on several implants occurs when the washing space is incorrectly created.
- When abutment is badly fixed on the implant and there is a gap between them. You will immediately feel an unpleasant smell, inflammation will begin around the implant.
- When the angle between the implant axis and the crown axis is greater than 27 degrees. This leads to inevitable bone resorption and gum recession (an exception is made for implantation using the all-on-4 procedure).
- Incorrect configuration (shape) of the crown can lead to the unwinding or fracture of the abutment.
- Incorrect fissure-tubercular crown contacts on the implant with the teeth antagonists lead to implant overload and bone resorption ...
- If the prosthesis is done in the absence or a small amount of attached gums, or the thickness of the gums is 2 mm or less. If the doctor in this situation does not suggest a corrective operation to increase the size of the attached gingiva / gingival thickness around the neck of the implant, then this will inevitably lead to inflammatory complications, bone resorption around the neck of the implant and the gum recession exposing the threads of the implant.
- When the bridge is fixed on the one hand on the implant, and on the other hand - on its own tooth. So you can not do it categorically, because own teeth are always slightly mobile, and the osteointegrated implant is completely immobile. This design will lead to loosening and tearing of the implant. We hope that our article was useful to you!
Author: implantologist surgeon Kamensky K.V., 19 years experience.