Plastics for making of unremovable prosthetic appliances

In orthopaedic stomatology plastics are used for the crownmanu facturing and revetment of unremovable dentures (pressed-soldered and solid-cast). More frequent there applical the plastics Sinma-M| and Sinma-74|). This acryls plastics of the hot hardening|thermosetting| of type - powder liquid. Powder is suspensoids semipolymer| weth fluok; the liquid is the mixture of acryls monomers and oligomers. The liquid Sinma-74| does not contain|maintains| oligomers, that is why|that is why| it|it| can be applied for the direct design. Due to the presence of oligomer in Sinma-M for | the prolonged|extended| time of viability of mass in the plastic state|figure, camp, mill| that allows to design revetment directly|immediately| from a plastic, evenly to inflict|drifts| it|it| and distribute.

To use Sinma-M| for revetment of prosthetic appliances is possible by two methods:

1) by the design of revetment directly|immediately| on the framework of denture;

2) by packing of plastic in the cuvette.

Advantage of the design directly|immediately| on framework of prosthetic appliance consists in that it is possible to do without labour intensive stages (design from the beeswax, gypsuming|plastering| in a cuvette, evaporation|boiling-out| of beeswax, drawing|extraction| out of the prepared construction from a cuvette).

Long time the stay of plastic in the plastic state|figure, camp, mill| (to 30 min|.) allows to design revetment by the masses of different|diverse| tint directly|immediately| on the framework of denture, that provides|secures| high aesthetical characteristics|aesthetic| of prosthetic appliances.

For polymerization there useed apparatus-polymerizator stomatological PS-1|, that is produced by the Kiev factory of automatics named after Petrovsky| or foreign|foreign| analogue " Ivomat|" firm of Ivoklyar (Germany). In these apparatuses Sinma-M| is polymerized during|for| 10 minutes at the temperature of 120°С and pressure 5 atm|. If there is a necessity in correction of prosthetic appliance, the second polymerization is conducted at the temperature of 100°С. It prevents formation of cracks between the metal and plastic.

For gradual polymerization of revetment of bridge like| prosthetic appliances of large|great, big| slowness is conducted the first, the second, etc polymerizations at the temperature of 100°С, and|but| last - at 120°С.

At making of revetment on the solid-cast frameworks by a direct method they apply the solid-cast metallic frameworks with retentional points|stations| which look like balls wetha diameter| 0.2-0.6mm. For this purpose is used|for this reason| a retentional set for metalloplastic| works. On the made wax model of framework evenly are inflicted|drifts| balls from the set. After mechanical processing metallic framework is subjected to the gritblasting by sand of middle grittiness. After this they polish the framework not touching areas which|what| are subject to revetment wash and dry out carelully.

Before setting on the model of framework ready for revetment, it is needed to insulate|insulates| all areas of gypsum|cast|, which can run into a plastic. The framework is depfived of fat by a monomer (ACRE-7), dry out on air and inflict|drifts| a thin layer of ground by a brush. Ground is prepared by mixing of powder and liquid of ED-02 to|by| chemo like| consistency. Retentional balls are needed to be carefully covered to|by| the full covering of metal by an even layer, not admiting a eeaking and bulgings.| The grounded framework is od ried out on air during|for| 15 minutes, then is placed|conclude| in the polymerizator| and maintain there 10 min|. at 120°С and pressure 5 atm|. In order to avoid discoloration|changing| of revetment the ground coverage before tracing|applying| of the plastic must be dry and hard.

Then gather additionally powders of plastic for the recreation|reproduction, reproducing| of layers of dentine and enamel. Every powder of dentine from the set of Synma-M| by the color answers one of numbers of unique|single, sole, only, common| scale of the stomatological colouring. At the necessity of obtaining the color with more intensive tint the to|by| basic|main| powder they add some of concentrate of dye-stiff of necessary color and carefully mix. For the select of color of dentine they pick up the proper color of powder of enamel.Enamel of color №1 is used with the light|luminous| colors of powder of dentine of numbers 6, 10, 12 and 14, and|but| enamel of color №2 - with the colors of numbers 16, 19, 20 and 24.

Process of preparation of plastic is such. Powder of dentine and lignid are mixed up liquid in by volume (3: 1) or mass (2: 1) correlations in a porcelain or glass crockery. The closed tub|vessel| with mass leave for swelling during|for| 6min|, if a technician works with a spatula. For this time the mass 1-2 times is mixed. In the closed tub|vessel| mass keeps|saves, stores| working consistency during|for| 20-25min|., in opened - during|for| 15min|.

If a technician works wint a brush, it is possible to use mass in|from, because of| 1 minute after the premix and to|by| the change|changing| of consistency (geling). Thus it is prepared|it| at mass in correlation powder liquid - 2: 1, 5. In order that mass did not stick to|by| the spatula it is slightly| moisten |it|by the liquid of Synma-M|. The|drifts| mass is traced on the framework by small portions, giving shape of necessary tooth to the revetment. It is not needed to trace|drifts| a lot of mass, the thickness of layer must not exceed 3 мм|, because more thick plastic can give cracks in the process of polymerization.

If a framework has a large|great, big| length revetment must be designed either|or| quickly or consistently for 3-4 units, in order to avoid drying up of mass on the modelled areas. The design begins from dentinal mass which|what| is traced wedgelike, leaving free mesial| and distal| sides|flanks| and also cutting edge|place| of the crown.

Processing and polishing of prosthetic appliance is conducted by ordinary|usual| methods.