Making surgical templates for implantation scientific article. Dental implantation according to navigation templates

Dental implantation is a precise procedure that does not tolerate approximate calculations. When installing implants, a deviation from the intended position even by 1-2 millimeters can adversely affect the effectiveness of treatment, and the surgeon’s work “by eye” can result in complications for the patient. innovative technology implantation according to a 3D template allows you to install implants, and then a prosthesis with jewelry precision. The orthopedic doctor of the StomArtStudio Leonardo clinic Vasiliev Leonid Alekseevich talks about the features of creating and using a 3D template.

How does traditional implantation work without a 3D template?

During surgical operation the doctor cuts the gum, folds back the flap, gaining access to the jawbone. Then, using a special tool, he makes a recess in it and carefully installs an artificial tooth root - an implant, after which he sutures the wound. This approach is too traumatic and involves a rather long period of wound healing.

The doctor determines the places for implant installation on the basis of a panoramic X-ray image (orthopantomogram), digital models of the jaws and computed tomography data. At the same time, the planning and conduct of the operation largely depends on the professionalism and experience of the surgeon. To avoid possible errors during implantation, reduce its traumatism and reduce the time of the procedure, scientists and dentists have developed a technology for installing implants using a 3D template.

What is a 3D template?

This is an individual model of the patient's jaw, created from biocompatible materials. On it, taking into account the angle of inclination, the exact places for the installation of implants are marked. Implantation takes place strictly according to this pattern. Before its manufacture, the patient is given computed tomography, then the doctor takes casts of the jaw.

After drawing up a treatment program (choosing a model of implants, their number, and so on) and agreeing it with the patient, the modeling stage begins. With the help of a computer program, the surgeon chooses the optimal places for placing implants, taking into account the volume of the jawbone, the location of nerves, blood vessels, maxillary sinuses. This avoids damage and injury during subsequent implantation. The doctor determines the size of the implants, the depth of installation, the angle at which they should be located in the bone. Work on the template takes only a couple of days. Its result is the model itself, created on a 3D printer from a biocompatible material. The template is sterilized before implantation.

3D implantation is indicated in cases where the patient needs to fix three or more implants in one visit. We also recommend this technology when placing one or more implants with immediate loading, such as anterior teeth. The 3D template also helps to perform implantation in patients with bone atrophy.

How is 3D implantation carried out?

The surgeon fixes the template in oral cavity patient and precisely fits the implants. Flap surgery is not required: the doctor makes only small punctures in the gum, the diameter of which corresponds to the size of the implants. Thus, the traumatism of the operation is minimized, the gum does not need to be sutured, and there is no risk of inflammation with good oral hygiene. Implantation is carried out under local anesthesia. It takes 10 minutes to install one implant. Possible error does not exceed 20 microns.

Clinical case StomArtStudio Leonardo, doctor Vasiliev Leonid Alekseevich

Modern implantology seeks to ensure that implant placement operations take place using a surgical template made according to an individual project for the patient.

There are two types of Implant-Guide templates:

1. surgical guide has bushings of small diameter for pilot drilling;
2. The implant template has large-diameter bushings, through which you can not only drill, but also install implants without removing the template.

The doctor chooses the template variant based on the clinical situation in the Implant-Assistant program.

Manufacturing Implant-Guide

A 3D Implant-Guide model (surgical or implant template) is created in the Implant-Assistant software module. The main convenience is that all information, from the processed computed tomography examination to the creation of a template, is contained in a single format. From the Implant-Assistant file computer model The Implant-Guide goes to the Implant-Guide module and then to the 3D printer.

Our Center uses printers from Objet, a world leader and expert in prototyping. The template is made within a few hours by layer-by-layer application of photopolymer materials to the platform. Each layer is very thin (16 microns), cured with UV light.

Next, titanium bushings are pressed into the template, which contain information calculated to a hundredth of a millimeter about the direction of the drills and the drilling depth. It is also possible to manufacture a template with bushings for fixing screws, which ensures its rigid attachment to the jaw. Implant-Guide can be used almost immediately after production.

The essential advantage of the Implant-Guide is that it is assembled in one place, very quickly, absolutely precisely and does not require a specialized laboratory.

Video of operations by using templates.

Imagine a mouthguard that athletes wear over their teeth to prevent injury. The template for implantation of teeth looks like it. This is a kind of stencil made using impressions from the jaw, which is necessary to carefully plan the location of future artificial roots and crowns. In those places where the patient is planned to install implants, there are sleeve holes in the stencil. Before starting work, the implant surgeon imposes a template on the operation area, resulting in the ability to act with high accuracy when installing the implant in a computer-calculated place at a given angle and at a given depth.

The use of surgical templates in dental implantation

Making a surgical template for dental implantation is not always necessary. If we are talking about the absence of one or two teeth, and not the front ones, there will be no special need for such a technology. However, in the case of complex prosthetics, when it is necessary to install several implants, it is not easy to do without a template. If the neighboring teeth do not serve as landmarks, it is problematic to determine the optimal place for placing an implant on the eye.

Surgical templates are also used for implantation in anterior section dentition. In this case, aesthetics is extremely important; how the patient's smile will look depends on the accuracy of the surgeon's work.

In case of bone atrophy in a patient, the art of a prosthetist in some cases helps to avoid bone grafting: using a template, implants can be installed in places that can withstand the load. Surgical templates are also used when installing implants for prosthetics on beam structures.

Indications for use

• Absence of three or more teeth in one jaw row.
• The need to replace front teeth with implants.
• Identified clinical anomalies in the structure of the jaw, which imply the need to drill at a large angle.
• The need for a flapless, minimally invasive surgical solution.
• Installation of a fixed or conditionally removable beam structure.
• Immediately after the implant is placed, a temporary crown will be placed on it.
• The patient has bone atrophy, and the implants must be directed to the jaw processes that go to other bones.

Making templates for implantation

Surgical templates differ from each other both in the way they are made and in the material. So, acrylic templates in their appearance resemble the usual removable prosthesis with gingival base and holes for pins; they are made in the laboratory using a cast from the patient's jaw. Transparent, soft and at the same time very durable templates made of polymer plastic are made in a vacuum former. And the most accurate templates for implantation owe their appearance to digital modeling, or rather to such a form as CAD / CAM technology.

Pros and cons of surgical templates

• More favorable prognosis of the operation: the human factor is minimized, the accuracy is maximum.
• The operation takes less time: the positions where the implants need to be installed are already calculated and marked.
• The invasiveness of the operation is reduced: when using a template, the surgeon does not cut the gum, but immediately pierces it in the place indicated on the template.
• Hence, healing is faster. The risk of inflammation and swelling after implantation is minimized.

• Making a template for implantation takes some time; this can be unnerving for those who want to get it over with as soon as possible. medical manipulations and forget about them. Typically, a template is made in two to three days.
• If it is decided that the patient needs guided implantation, the price that will have to be paid for new teeth may increase. True, this does not always happen: for example, when using a template allows you to refuse to build up bone tissue, this, on the contrary, reduces the cost of prosthetist services.

What is the cost of guided implantation?

The cost of the template may vary depending on the material, manufacturing technology and the number of guides. So, an acrylic surgical template, provided that it is planned to install less than three implants, can cost from 6,000 rubles, and a template made on a three-dimensional printer using the latest computer technologies for installing more than three implants will cost from 30,000 rubles. This amount must be added to

Navigational (Surgical) templates is an overlay with guiding cylinders for accurate positioning of implants in the oral cavity in accordance with the planned position on the computer for computed tomography.

Advantages:

• Safe implantation in all situations.
• Preparation of ideal conditions for prosthetics.

• Minimal trauma, high accuracy.
• Reducing the number of possible complications.

Types of navigation templates

Based on bone. This type of template is best done according to MSCT, because it best conveys the relief of the bone. As a rule, during the operation with such templates, tilting of large areas is required. soft tissue. Such templates were made at the dawn of navigational implantation and are now used extremely rarely or when necessary.

• Based on teeth. This type of template, like the next one, is the most common today. A CBCT and an impression/model of the jaw are already required to perform this work accurately. Next, the model is scanned in laboratory scanners and after that the three-dimensional model of the jaw obtained from CT is combined with the three-dimensional model of the scanned plaster model. In this way, we get the exact relief of the teeth for creating templates.
• Based on mucosa. This type of template, as well as with tooth support, is also used frequently, but mainly with complete edentulous or few remaining teeth. True, in this case, an additional stage appears - the creation of a radiopaque template, which allows, with complete adentia, to see the mucosal relief on CT scan, the intended location of future teeth and makes it possible to correctly plan a future operation.

Production time: 4 days

x-ray template

Imaging

Implant planning

Discussion

• template sterility,

• reduction of operation time,
• lower cost.

Today, surgeons and orthopedists have a wide range of different systems and software for 3D implant planning, which allow the use of the obtained data for the automated production of surgical templates. The SICAT planning module is an integral part of Sirona's Galileos digital volume tomography software. Unlike other systems, SICAT is based on pre-imaging templates and is only used for pilot bur insertion. With this module, we can implement a simple, easily standardized workflow.

Currently, three-dimensional X-ray diagnostics is an almost mandatory component of implant treatment. The first system (NewTom, Italy) of digital volumetric tomography (DVT; English name: "conebeam computed tomography", CBCT) began to be used for dental x-ray diagnostics in the late 90s. Since then, DVT, also due to the lower radiation exposure to the patient, has gradually replaced traditional computed tomography in all areas of dentistry. Three-dimensional diagnostics and its visual results in DICOM format have greatly expanded the possibilities of planning. However, certain difficulties arise when combining a virtual picture with an individual clinical situation. In implantology, two methods are used to solve this problem.

The results of 3D diagnostics can be directly used during surgery using the appropriate navigation systems. To do this, the operating space must be limited by a system of fiducial points. In addition, in this space, for example, using infrared markers, it is necessary to localize the tools used. Such systems are successfully used in other areas of surgery (neurosurgery or spinal surgery) and have already been adapted for the purposes of dentistry and implantology.

According to another method, the results of 3D X-ray planning are recorded in the process of automated production of surgical templates (CAD/CAM templates). Such templates, even without the 3D planning information recorded in them, have been used for a long time to transfer the planned position of implants into the oral cavity and have proven themselves from the best side. Existing methods for the use of such templates, made on the basis of two-dimensional X-ray diagnostics, are not only widely used in practice, but are still being developed and improved.

Existing planning systems and surgical templates based on them can perform various functions and vary considerably in their complexity. All these systems have sufficient accuracy and reliability. Below is my own practical experience using the SICAT planning module, implantation planning for 72 patients has been carried out using this system in the last 12 months.

Description and technological process

The material basis for the use of SICAT templates is a special set (Starter Kit), which, among many other things, includes bite plates with fiducial markers. Unlike other systems, SICAT is based on templates made before imaging. When planning implantation, a traditional panoramic x-ray (orthopantomogram) is first taken and clinical diagnostics, then casts of the upper and lower jaws are made, and, if necessary, also a recording impression of the occlusion.

x-ray template

For DVT, individual X-ray templates are made, which are a film splint with radiopaque (containing barium sulfate) analogues of teeth in the implantation area and a fixed bite plate. On fig. 1 shows a model of the initial situation with a 1.5 mm thick film tire over Setup. In this clinical case, it is planned to restore the shortened dentition on both sides mandible using crowns supported by Camlog implants.

Rice. 1. Model (superhard plaster) of the initial situation with a 1.5 mm thick film splint over the Set-up.

Imaging

When the template is ready, the patient is sent for X-ray diagnostics. After trying on the template, the Galileos spherical head holder is individually adjusted to ensure maximum scanning accuracy. After scanning, a detailed consultation is held with the patient, during which, with the help of the formed visual picture, all the features of the initial situation are explained to him in detail. Thanks to this, the patient gets the most complete picture of the volume and duration of treatment, the need for additional augmentation and possible costs. This is a very important step, because surgical treatment can be started only after obtaining the consent of the patient.

Implant planning

Detailed planning of implantation is carried out in the absence of the patient at the workplace of the Galileos system. The system database contains information about all common implant systems and makes it easy to switch from one type of implant to another and select their length and diameter. We have both a three-dimensional image and layered images at our disposal. It is recommended to work with panoramic and local layered images, since a three-dimensional image does not contain any fundamental additional information.

On fig. 2 shows the results of implantation planning. First, on both sides of the jaw, the location of Canalis mandibularis is indicated. To do this, 6 points are indicated on the left side, and 7 points on the right side, which are connected to each other automatically.

Rice. 2a. panoramic image.

Rice. 2b. Pseudosagittal section of the IV quadrant.

The optimal position of the Camlog ScrewLine implants is then selected using individual layer-by-layer images at optimum magnification. This example illustrates very well possible problems arising from the installation of implants in the area of ​​distal chewing teeth lower jaw (Fig. 3):

• Tooth area 37. The lingual surface of the lower jaw has a concave shape with a small radius of curvature. Therefore, only an implant with a size of no more than 5.0 x 9 mm can be installed along the optimal axis, and there is a risk of forming an unfavorable ratio between the dimensions of the implant and the abutment. Neither block graft augmentation, nor Bonespreading, nor nerve displacement allow the placement of a 5.0 x 11 mm implant in this area and augmentation of the vestibular cortical plate with bone chips.
• Tooth area 36. The concavity of the lingual surface is less pronounced here, which allows the placement of a 4.3 x 11 mm implant in this area. However, there is a risk of perforation of the mandible if the preparation is too deep.
• The area of ​​teeth 46 and 47. In the IV quadrant, the anatomy of the lower jaw is less demanding on the size of the implants. In the region of tooth 46, there is a risk of nerve damage if the preparation is too deep, but the 5.0 x 11 mm implant can be placed at a sufficiently safe distance from the nerve. In the region of tooth 47, a 5.0 x 11 mm implant can also be placed.

Rice. 3. A typical report on the results of planning.

When planning an implant Special attention should be given to the choice of the optimal angle of inclination of the implants. The initial vertical position is often inconsistent with the inclination of adjacent teeth and the shape of the occlusal plane. After adapting the angle of inclination of the first implant to the shape of the plane of occlusion, this ratio can be automatically extended to all other implants. A typical report generated after the completion of virtual planning contains all the necessary information to discuss its results with the dentist and dental technician and draw up a treatment plan.

Transferring planning results to a surgical template

The results of the planning are recorded on the Starter Kits CD and sent to the clinic along with the X-ray template on the plaster model (packed in the supplied hygiene bag), the report and the optimal pilot bur diameter. Only 2 out of 72 SICAT cases required additional data. In this case, we are talking about patients with microsurgical grafts after removal malignant tumors, for which the templates were not located in the same position during scanning as on the model. In all other cases, the results of planning are easily transformed into a surgical template. To do this, remove the bite plate from the X-ray template, cut off the crowns of the teeth in the area of ​​implantation, and insert guide sleeves for the pilot drill into them along the axis of the implants.

Discussion

It is possible to use this template only for introducing a pilot drill, which greatly simplifies and reduces the cost of using the system (Fig. 4).

Rice. 4a. Panoramic image after manual marking of the nerve position and virtual placement of two implants.

Rice. 4b. Cross section in the planned position of implants 36 and 37.

Rice. 4c. Fragment of a panoramic x-ray of the situation after the installation of implants.

The cost of such a template without DVT is about 400 Euros, and no special tools are needed during the operation. With successful planning of implantation and right choice diameter, length and angle of implants, the use of a template only for the introduction of a pilot bur allows you to bring planning results to life with high accuracy. The risk of insufficiently precise insertion of the pilot bur only exists in areas with a thick gingival layer, for example, in the region of the distal maxillary posterior teeth, where, due to the addition of the height of the sleeve and the thickness of the gingiva, the direction of the preparation may differ from the planned one. A similar problem arises in the region of the second molar in the presence of adjacent teeth, when the introduction of a pilot bur along the planned axis is very difficult. In such cases, we can partially omit the use of a surgical guide and insert a pilot bur without one. Carrying out accurate three-dimensional planning allows you to do this without significantly increasing the risk of any complications. Alternatively, external guide sleeves can be used.

For the successful application of the described technology, it is necessary to know all the fundamental problems of surgical templates, among which Weibrich and Wagner note the following:

• discrepancy between the results of planning and the structure of the bone base,
• the difficulty of fixing the templates in the optimal position after the preparation of the mucoperiosteal flap,
• template sterility,
• contamination of the bur and bone base by particles of the guide sleeve,
• limited accuracy of preoperative planning.

For experienced implantologists, the use of the described technology has a number of advantages:

• reduction of operation time,
• increasing the reliability of planning in relation to the required result and the need for additional augmentation,
• visualization of all necessary measures for the patient,
• ease of practical application,
• lower cost.