Annotation
Traditionally, for the manufacture of removable inside oral apparatus, prostheses, orthodontic devices, temporary crowns and bridges, the method of replacing wax reproduction with a plastic mass (polymer) in a ditch is used. This technique takes a lot of time, requires significant additional finishing, obligatory use of a dental laboratory and is expensive. In addition, the traditional technique does not allow to create many devices from modern plastic materials such as, for example, for teeth whitening, fluoride applications, etc.
Modern vacuum technology significantly expands the capabilities of the doctor and his ability to satisfy the patient’s desires in an effective and economical manner in an unusually short time. Vacuum technology creates additional opportunities also for dental equipment of any profile, allowing you to quickly, inexpensively and cleanly create devices and prostheses, which are often not feasible by the traditional method. Materials for dentures that replace traditional ones are hygienic, better tolerated by the patient, non-toxic, non-porous, do not cause allergies, and do not contribute to the growth of bacteria and / or fungi.
For the doctor, who is constantly looking for new and more advanced methods of improving clinical results and expanding the range of services to the public, new technology and materials can succeed where conventional technology complicates daily activities and increases the cost of procedures.
Model
The model is one of the most important elements for obtaining a good vacuum-shaped intraoral device.
The model should be clean, not containing pores, bubbles and layers. In some cases, pronounced undercuts should be blocked.
The model should not be too high. The higher the model from the cutting edges to the base, the less vacuum pressure affects the formation of the device. The higher the model, the greater the deformation and thinning of the plastic.
The base of the model should not be too large. The smaller the base area, the more open holes for vacuum traction. It does not matter if vacuum forming is used under pressure.
A better model should be made of gypsum, which is not as dense as other materials and is able to pass a greater vacuum through itself. If conditions allow, you can create an additional hole in the base or remove the base, leaving only the crests and dentitions. For vacuum forming under pressure, the material of which the model is made does not matter.
An integral part of successful dental practice is the expansion of patient services. The mastery of all clinical disciplines and their creative use in developing a treatment plan, allow the dentist to stand out and attract more patients seeking thoughtful, knowledgeable and possessing advanced clinical skills of doctors.
Vacuum molding technology allows the dentist to expand the boundaries of his restorative practice from replacing parts of teeth to replacing individual teeth, dentition and providing orthodontic and cosmetic services simply and efficiently. At the same time, the doctor completely controls the creation of intermediate and permanent structures independently, often without the participation of a dental laboratory, saving money and time for himself and the patient.
Using a vacuum machine and forming material:
After the model is prepared, the thermoplastic material is selected and heated under the heating element. Vacuum pressure contributes to the deformation of the plastic, which is processed after cooling. The use of an additional device for forming under pressure contributes to a better adaptation of the plastic to the model.
1. Turn on the heating element to preheat.
2. Frame the desired thermoplastic plate. Secure the frame with a screw and lift it to the top point close to the heating element.
3. Place the model on a vacuum table (in addition, the model can be treated with a silicone sprayer for better subsequent release).
4. Allow the thermoplastic plate to warm up well and go down. Warming up time depends on the quality and thickness of the plate. Thin plates (.020) are considered ready when you see that they have fully warmed up and sank down by 1-1.5 cm. For a thicker material (.150), the draw should be 1.5-2.5 cm.
5. After the warm-up has occurred, and the material is pulled down, turn on the vacuum and lower the frame all the way to the model. Wait 20-30 seconds. for the best adaptation of the material to the model. For better adaptation, crimp the material on the model with a wet towel with a working vacuum, pushing the heating element to the side.
6. For thick and thick plates, you can use an additional device - a pressure doom (pressure cup), which is connected to the compressor and placed on top of the frame. With a working vacuum, the dome creates additional pressure from above, compressing the model even more tightly, which may be important for some materials. It is important to note that too much pressure can contribute to thinning the material.
7. Turn off the vacuum and heating element. Loosen the frame fixing screw, loosen the model with the plate and allow the material to cool on the model. The cooling time will depend on the quality and thickness of the material. You can put a model with a plate in cold water to accelerate.
8. Remove the received device from the model, using scissors and a sharp blade for thin materials, and for plastic dense and thick plates - boron, laboratory and circular cutter.
Selection of thermoplastic material:
The materials most commonly used for molding vacuum technology in dentistry are:
Polyethylene is characterized by the presence of a polymer chain, including "–CH2-CH2-" and is used for soft bite structures, mouthguards for the application of fluorine, surgical stents, sports tires, orthodontic appliances, etc.
Polyvinyl chloride contains in its polymer chain "СН2-СНСL", giving it the strength and rigidity needed in tires, double plates for hard-soft structures, orthodontic appliances and small removable prostheses.
Polypropylene has a "-CH2-CH (CH3)" chain and is used to make temporary crowns and bridges, molds for crowns, temporary orthodontic retainers, and caps for posts.
Polystyrene contains the group "-CH2-CH (C6H5)" and is used for individual spoons and fitting bases for prostheses.
Polycarbonate contains the “–O-CO-O-” group in its chain and is used to produce temporary crowns, bridges and orthodontic retainers.