CS211580B1 - Wax model material for the production of preforms for dentistry - Google Patents

Abstract

The invention relates to a wax model material for the production of preforms for dentistry, which is used in particular for the production of dental prostheses. The wax model material based on paraffin, montan wax and resin additionally contains a precisely determined amount of additives (microwax and ethanolamine salt of alkylbenzenesulfonic acid), which have a very positive effect, in particular, on the achieved mechanical properties (elasticity, flexibility) and eliminate unwanted springing during work with the wax model material.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wax pattern mass for the manufacture of preforms for dentistry, in particular for the manufacture of dental restorations.

As is known, in dentistry dentistry, the casting method is a casting method in which parts of the dentures are formed, first of all from wax, after which the ceramic is cast and melted into the cavity thus formed. Efforts to significantly improve, make productive and facilitate the work of porn technician by so-called wax preforms - or prefabricates - are increasingly apparent. '

Of these, namely, the technician can denture compose (i.e. model) is much easier and faster, ^x than the conventional method dropped onto and peeling of the wax to the desired shape It is therefore to create structural elements, e.g. buckles, crowns, of wires of non-circular cross-section, smooth Si raster foils whose bending, distance adjustment, shape change by light pressure and mutual bonding (welding) obtain the desired shape of the future denture.

For the preparation of wax preforms, waxes containing paraffin and a vegetable resin as a basic component have hitherto been used because of the colorlessness of the resulting mixture. Low molecular weight polyethylene is added to the base wax composition to increase processing flexibility. The disadvantage of this mixture, in addition to considerably higher costs and significantly deficient materials, is mainly that this wax model mass exhibits considerable memory at room temperature (when it is processed into a denture), ie residual elasticity (springing), which causes very undesirable changes in dimensions of the dental prosthesis. In addition, the wax composition used hitherto is insufficiently tacky, with the result that the wax preform does not adhere well to. gypsum model, sticks, falls off, etc., which worsens the quality of the resulting denture.

The achieved colorlessness of the wax mass, or the possibility of color differentiation of the individual waxes, is not essential in terms of dental restoration, and any advertising effect cannot outweigh the considerable cost of producing the wax mass from these deficient materials.

It is an object of the present invention to overcome these drawbacks of hitherto used wax patterns.

SUMMARY OF THE INVENTION The object of the invention is to propose a composition of a wax modeling material which guarantees its good mechanical and chemical-physical and technological properties, such as ductility, flexibility, sufficient shape stability, required tack, good compression and self-lubricating under pressure.

The object is solved by a wax model mass, the essence of the present invention is characterized in that it contains an additive of 5.0 to 35.0% by weight of micro-wax and 0.5 to 5.0% by weight. % ethanolamine salt of alkylbenzene sulfoacid.

The wax pattern according to the invention exhibits considerable ductility, flexibility and desirable tackiness and, due to the use of the ethanolamine salt of alkylbenzene sulfoacid, excellent surface wettability of the preforms in the application of ceramic coatings, as well as good compressibility and self-lubricating under pressure.

The wax model mass is also durable and made of affordable materials. The preforms made of this wax model mass can also be shaped and adapted at any room temperature without pre-heating. The wax model mass is also easily and perfectly fusible or combustible practically without undesirable solid residues or ash.

Further advantages and features of the wax pattern mass according to the invention are more fully apparent from the examples of composition and description of the individual components used.

Example 1

87.5% w / w paraffin 5.0% w / w montan wax 1.0% w / w montannl resin 1.0% w / w ceresin 5.0% w / w microswax

0,5% by weight of ethanolamine salt of alkylbenzenesulphonic acid

Example .2

5.0% w / w paraffin

35.0 SS montan wax by weight

10.0% by weight montannl resin

10.0 wt% ceresin

35.0% by weight of microwax

5.0% by weight of an ethanolamine salt of an alkylbenzene sulfoacid.

Paraffin - along with montan wax predominantly as a major component of the wax model mass - is a mixture of solid paraffinic hydrocarbons saturated with a series of dewaxed mineral oils. It is a white solid with a coarse crystalline structure, ensuring perfect homogeneity and mixing of all the components (they dissolve in it in any ratio) and giving the finished preform a smooth and glossy surface.

Ceresin, as a mixture of solid refined, predominantly isoparaffinic hydrocarbons, obtained during dewaxing of mineral oils, significantly affects the mechanical properties of the alloy, in particular its elasticity and ductility.

Another important component is montan wax, which is obtained as a brown coal extract. This extract is a mixture of a wide variety of chemical substances. The base consists of wax substances composed mainly of esters of high molecular acids with higher alcohols, free acids, primary and secondary alcohols and ketones. This wax contains 1 minor amount of resin and asphalt materials. This appearance of brown to black gives the alloy a brown color, which is desirable in this case, since the preforms are modeled on a gypsum base and light, respectively. Colorless preformed waxes soon become tired of the eyes, as their contours are not very visible on the substrate.

Furthermore, it significantly contributes to the resistance of the mass to pressure, which is important in adapting the preforms to the pressure, which in addition requires the wax preform to bend and adhere to the gypsum substrate without distorting its cross-section.

in

The assembly resin is readily obtainable from the assembly wax by extraction with suitable solvents. It is a dark brown hard and very brittle mass that exhibits considerable tackiness when hot; greatly increases the overall strength and flexibility of the composition, particularly when hot, which is very important when removing the wax preforms from the mold cavities.

A qualitatively new and higher effect of eliminating undesired springing and of improving the mechanical properties important for the production is represented in the examples by the addition of a microwax and an ethanolamine salt of an alkylbenzene sulfoacid.

Microwax is a petroleum yellow oil composed of hydrocarbons of alkanes and alkenes with a very fine microcrystalline structure, having up to 20% of petroleum oils bound in the crystals. The microwaxes are generally suitably modified by the addition of polymerized hydrocarbons. Their very fine crystalline structure, unlike other waxes, does not change even with slow cooling. The microwax gives the alloy a fine crystalline structure, removes the so-called memory, good press workability, which is especially evident when producing very thin β-shaped wax preforms, since the microwax ensures perfect filling of all mold cavities.

The ethanolamine salt of alkylbenzene sulfoacids - a light brown viscous liquid, well soluble in molten waxes - ensures, by its properties, the finished preforms as well as substantially better wetting of their surface with coating suspensions. It also causes the wax mass to be processed by pressing.

This corresponds to the deletion of the molds by the separating means and, in addition to the higher machine power, this material ensures that there is no local accumulation of the separating means in the mold cavity, which would have a negative effect on the surface of the molded dental prostheses. Said salt also greatly influences the slipperiness of the processed wax pattern mass, which has a very positive effect, for example, in the production of drawn preforms.

For the sake of completeness, it should be added that the preparation of the wax pattern mixture from the components described above is carried out by a conventional melting process by first melting all the wax components and then adding the ethanolamine salt of the alkylbenzene sulfoacid to the melt. It is only necessary to ensure that the temperature of the melt does not exceed 150 ° C, as this ethanolamine salt may be undesirable.

Claims (1)

SUBJECT OF THE INVENTION Wax model mass for the production of preforms for dentistry, in particular for the manufacture of dental substitutes, containing 5.0 to 87.5% by weight paraffin, 5.0 to 35.0% by weight montan wax, 1.0 to 10.0% by mass montan resin and 1.0-10.0% by weight of ceresin, characterized in that it comprises an additive of 5.0-35.0% by weight of microcoswax and 0.5-5.0% by weight of the ethanolamine salt of alkylbenzene sulfoacid.