The preparatory stage before the installation of orthopedic products is the procedure called modeling of teeth. By it is meant the reproduction of the cavity of the tooth, its external shape or part, for example, of a wax crown. This is necessary in order to visually understand how the dentures will look and how comfortable they will be.
Features
In dentistry, modeling of teeth from wax is called Wax-up-technology. Dentists use two methods of such modeling. One is the formation of a sample of the future tooth on stumps (gypsum bases), and the second is the combination of the Wax-up and Mock-up methods, the creation of a composite model right in the mouth based on wax.
This is a mandatory procedure when performing orthopedic correction of oral defects. Models need to be made for many purposes. First of all, it is necessary for the doctor to draw up a plan for the upcoming restoration. The wax model serves as a test material, according to which the orthopedist andthe technician determines the method of restoration of the damaged tooth, discusses the scope of further work and possible difficulties of prosthetics.
If there is a model, it will be easier for the patient to explain all the features of the treatment and agree on the final type of teeth. The implementation of this work will allow at the initial stage of manufacturing the prosthesis to eliminate all its inconsistencies and inaccuracies.
Wax is the most suitable material, which lends itself well to processing, and after it cools down, quickly and easily takes the desired shape. To do this job, it has excellent characteristics, namely:
- quite plastic;
- tight;
- durable.
The technician, thanks to these properties, is able to very accurately recreate the necessary dimensions of the tooth so that the prosthesis made is as similar as possible to his own. Wax modeling of teeth is needed to work out the nuances of future work to restore the functionality and aesthetics of the dentition.
Benefits of Simulation
Thanks to this universal procedure, the final design is perfect. She has clear advantages, these are:
- impossibility of damage to neighboring teeth when wearing a prosthesis;
- no discomfort as the size exactly matches the parameters;
- possibility to eliminate all inaccuracies and errors due to amenable material even at the initial stage.
Properly performed simulation significantly reduces timegetting used to the prosthesis, because the design stands out for maximum convenience.
Flaws
Wax modeling and restoration of teeth is considered an ideal technique that has no drawbacks. However, there is a minus, which concerns the material itself. Wax, when compared with others, has a fairly high rate of thermal expansion. This is due to its polymerization. As a result, there are discrepancies in the dimensions of the castings and insufficient fastening of the cast prosthesis. To prevent this from happening, a method of filling measurements is used by expanding the molding material and applying a compensation varnish.
Indications
Based on the state of the oral cavity, an orthodontist may prescribe artistic modeling of teeth with increased destructibility of the area above the gum, which manifests itself due to advanced caries. In this case, it is necessary to restore the tooth walls by using microprosthetics or a crown. Also with abrasion due to abnormal features, for example, malocclusion. You can get rid of this defect with the help of veneers or crowns.
Distinguishing color refers to indication. When installing the implant, it is possible to choose the desired color, but first you need to carry out the modeling procedure. With the destruction of a whole dentition, a wax cast is an obligatory step in their restoration. If only the root remains, modeling is indispensable. The complete absence of teeth - adentia - is one of the indications for thisprocedures. The same applies to the presence of multiple pathological defects. If you need to install several crowns, a bridge structure, then a wax cast is certainly created. The Wax-up procedure allows taking into account the individual characteristics and wishes of the client.
Contraindications
Wax modeling of the shape of the teeth is considered a completely safe and painless procedure for the patient. It does not cause any discomfort and discomfort, it is performed without the use of painkillers. However, there are some contraindications for its implementation. These include:
- diseases of the tissues of the bone jaw;
- recovery period after radiotherapy;
- inflammatory processes of a different nature;
- drug cravings;
- acute form of oral anomalies.
It is also necessary to take into account the fact that natural raw materials, namely beeswax, are used to build casts. Therefore, in relation to people who are allergic to honey or bee products, this technology is prohibited. If there is a reaction to the material, the patient must notify the doctor so that he can select a safe technique for prosthetics and recovery.
Indirect modeling
Indirect modeling and restoration of teeth involves the creation of an impression of the future artificial denture on a plaster basis. This method does not take much time. The patient does not need to attend a doctor's appointment for a long time. The dentist must make high-quality casts of the oral cavity, and the final production takes place in the laboratory. The indirect technique is convenient to use for teeth growing in hard-to-reach places.
Direct modeling
With the direct method of making a model from wax, the first thing the tooth cavity is filled with liquid wax or it is pressed into it in a plastic state. Then modeling and pinning is performed, and then the wax model is removed from the cavity. A composite specimen is created from the wax model in the mouth.
This option immediately creates artistic modeling and restoration of teeth, as well as their functionality. After the technician has done this work, the final version of the sample will be shown to the client and then transferred to the mouth using a special technique. With a temporary system, a person will have to walk for a certain time in order to assess whether the sample is made correctly and comfortably. If you need to correct, then the dentist will make all the corrections directly on the temporary models.
The direct method is most suitable for people with high enamel abrasion, as well as for those who have problems with the mandibular temporal joint, if necessary, increase the bite. In the absence of claims, the product is sent to the laboratory for the manufacture of a permanent design.
The main goal of the restoration of chewing teeth is functional rehabilitation, which depends on the anatomical correctness and accuracy of the structure being made. That is why the modeling of chewing teeth is mandatoryprocedure.
The direct method has a number of advantages over the indirect one:
- wax pattern is more accurate;
- you can eliminate the identified inaccuracies and shortcomings;
- it is possible to more accurately correct the boundaries of the future prosthesis in the region of the gum edges.
However, with it it is very difficult to correct inaccuracies on the lateral groups of teeth. Also, when adjusting the model, there is a danger of inadvertently damaging the mucosa with the instrument.
Main modeling tasks
Modeling a wax model from wax after filling the cavity with it comes down to three main tasks. The first concerns the fact that the wax impression is customized, taking into account the central occlusion and all the movements of the mandible. This is necessary so that the opposing teeth do not encounter obstacles on the inlay. Therefore, the doctor asks the patient to slowly close his jaws, after which he removes excess material. This is repeated several times until the teeth are completely closed. Next, gently move the lower jaw in all directions and also scrape off excess wax.
The next task is to ensure that the surface of the tab merges into the surface of the tooth and at the same time maintains the same plane without roughness and any recesses. This is very important to prevent the development of recurrent caries.
Another goal is to give the wax cast the correct anatomical shape. Most often, the appearance of the tab spoils its configuration, not the color. Often the ugly ones catch the eye:
- teeth;
- metal crowns;
- tab.
And if you look closely, you can see that the reason lies in the fact that the shape of the tooth does not correspond to the symmetrical. If the metal is given the correct anatomical configuration, then the inlay or crown will be invisible.
Material requirements
To model teeth, wax types 1 and 2 are used, the first is appropriate for the direct method, the second for the indirect method. This is due to their quality characteristics. The material of the second type has a lower quality, but this property does not affect the result of the model at all. The first type of wax is perfect for making an impression right in the patient's mouth.
There are a number of rules regarding the selection, preservation and use of this material. One of them concerns the fact that in order to obtain greater contrast, it is recommended to use waxes of different colors. After cooling, the material should not crumble, it must be rigid. The quality of the impression is negatively affected by the presence of crumbs in the wax mass during the heating process. If it contains particles, flakes, then the surface will not be smooth, but embossed. It should also be borne in mind that the material during scraping should not form chips or fall off in pieces. Exceeding the permissible shelf life negatively affects the quality of the wax.
Accurate and high-quality anatomical modeling of teeth depends on the correct selection of material for a particular method.
Preparatory process
Beforeto do wax modeling of teeth, it is necessary to fulfill a number of appointments, one of the first is the diagnosis of the oral cavity. If necessary, x-rays and computed tomography of the jaw should be performed. It is also noted that in case of diseases of the oral cavity, it is necessary to undergo a course of treatment. Do not forget to sanitize and follow the rules of hygiene.
Only after a full examination and treatment course has been carried out, the doctor proceeds to create casts.
Execution technique
Teeth modeling technique is performed in a certain sequence. First, casts are taken from the place where the temporary system will stand, and from the opposite side. A special dental silicone is used for this procedure. With the help of bite silicone rollers, the closure of the jaws is fixed. With the help of a special plate fixed near the ears, samples are obtained from the jaws with the direction of their direct movement. Such a plate is called a facebow.
Based on the data obtained, samples are made, which are then transferred to plaster. The next step is to fix the impressions on the articulator. This is a device that copies the movement of the jaws. Thanks to this device, the technician debugs the articulation and chewing movements of the teeth and jaws.
If the sample is converted into a Mock-up, then the result is transferred to the oral cavity. The cast is taken with silicone keys, deposits are removed. Glue is applied to fix the system. Plastic or composite is placed in the impressions, theirapplied to teeth. At the end, the impressions (silicone keys) are removed, excess material is removed, grinding and polishing are performed. After the fixation is completed, the doctor will evaluate the work performed from an aesthetic and functional point of view.
The task of modeling the tooth stump is to restore the anatomical shape, disturbed by both the pathological process in hard tissues and the preparation for the crown. The procedure is done using a special wax by gradual layering on a plaster stump. They also consistently restore the shape and relief of parts of the tooth:
- vestibular;
- lingual or palatal;
- chewing;
- lateral.
The most important thing is that the wax should not reach the neck line by 1-1.5 mm, otherwise its volume will increase, as a result, the crown will not be able to tightly clasp it. The simulated tooth should not be larger than the restored one. Between the lateral surfaces of the latter and adjacent teeth at the level of the middle, it is necessary to leave a gap in the thickness of the metal.
It should be borne in mind that wax modeling of teeth, which is an integral procedure when installing certain types of orthopedic structures in the oral cavity, is an expensive dental service. Significant price explained:
- cost per consumable;
- high precision process;
- using special equipment.
The number and complexity of modeling units of the dentition affects the cost, whichmay change. The specialist will announce the final price for wax modeling of teeth after the diagnosis. This procedure allows the patient to identify discomfort, and in the future to quickly get used to the prosthesis. This additional step in dental implantation is considered an impeccable method for prosthetics using various methods. Experts note that the procedure does not harm adjacent teeth, and the wax used is distinguished by its versatility and is absolutely non-toxic.
