CH630253A5 - Two-component system for preparing dental formed bodies - Google Patents

Description

The present invention relates to two-component systems for the production of dental moldings by polymerization of organic bifunctional ethyleneimine compounds with hardeners and the use of these systems for the production of artificial teeth, dental prostheses, models or dental prostheses, in particular also of semi-permanent or definitive crowns and Bridges.

Y— 0- R '_ 0

The organic bifunctional ethyleneimine compounds used hitherto commercially, in particular for the production of temporary crowns and bridges, as are known from CH-PS 484 977, correspond to the general formula

0_RT - 0 —Y

wherein R is an alkylidene or SO2 radical, R 'is a divalent organic radical and Y is an acyl radical of a carboxylic acid which is substituted by an ethyleneimine group.

65 In the practical manufacture of artificial teeth, dental prostheses, dentures and dental models, these known ethylene imine compounds are used together with suitable fillers, although

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found that when this mixture of bifunctional ethyleneimine compounds and filler, which had already been prepared for practical use, was stored, to which only the hardening catalyst was then added during the manufacture of the desired items 5

segregation symptoms occur after a short time by the filler slowly settling in the mixture. This meant that when the mixture was removed from the storage room, in the amount necessary for the production of temporary crowns and bridges or the like, the original mixing ratio of ethyleneimine compound and filler, as specified by the manufacturer, was not always present.

In addition, the sedimentation of the fillers in the lower region of the storage container resulted in an undesired prepolymerization of the ethyleneimine compounds, which affects both the production and the physical

Impair the properties of the end product. This sedimentation was based on the fact that the fillers used had a significantly higher specific weight than the liquid ethyleneimine compounds used.

As can be seen from DOS 2 404 380, attempts were subsequently made to remedy these deficiencies by using bromine-substituted ethyleneimine compounds in the benzene nuclei. As expected, these brominated ethyleneimine compounds had a higher specific weight than the unsubstituted analogues. This prevented the sedimentation and thus also the prepolymerization in a manner familiar to the person skilled in the art.

A major disadvantage of the brominated ethyleneimine compounds in the benzene cores lies in their high viscosity, as can be seen from Table 1:

Table 1

Ethyleneimine compound according to density viscosity in

(23 °) Poise (25 °)

unsubstituted DOS 1 720 574 1.120 110-185

dibrominated DOS 2 404 380 1.352 6120

dibrominated / unsubstituted 1: 2 DOS 2 404 380 1,188 227

tetrabrominated DOS 2 404 380 1.556> 10 000

tetrabrominated / unsubstituted 1: 4 DOS 2 404 380 1.186 240

tetrachlorinated invention 1,269 1,000

The brominated ethyleneimine compounds therefore have to be diluted with less viscous, unsubstituted ethyleneimine compounds so that after the addition of a filler which in turn causes thickening, they are suitable for the production of artificial teeth, dental prostheses, model materials or dentures. For this reason, the dibrominated ethyleneimine compound according to DOS 2 404 380 must be diluted with twice the amount of an unsubstituted ethyleneimine compound, and the t-trabrominated compound even with four times.

However, this in turn means that the insufficient physical properties of the unsubstituted ethy-

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Lenimine connections (namely low compressive strength and transverse bending strength as well as greater thermal expansion of the hardened product) come to the fore again.

It has now surprisingly been found that it is not only possible to eliminate the deficiencies mentioned with a new class of ethyleneimine compounds, but also to achieve significantly improved end products.

The two-component systems according to the invention for producing dental technical moldings are characterized in that the first component is an ethyleneimine compound of the general formula

Z-0.

0 —Y— 0.

contains in which

X is an alkylidene, cycloalkylidene or an SOz radical,

Y represents a divalent organic radical and Z represents an acyl radical of a carboxylic acid which is substituted by an ethyleneimino group, and n is 1 to 4 and the second component contains a hardener.

If necessary, the second benzene nucleus can also be substituted with up to 4 chlorine atoms.

These are ethyleneimine compounds with a significantly higher specific weight than the corresponding unsubstituted analogues, but which are not yet so viscous that they have to be diluted with poorer quality monomers in order to be invented at all.

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60

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to be used properly.

In contrast to the prior art, these ethyleneimine compounds can therefore be used alone in the first component.

They are characterized by rapid hardening after the addition of a suitable hardener (polymerization catalyst) even at room temperature and by a very low linear polymerization shrinkage.

In addition, the ethylene imine compounds used according to the invention give shaped articles with a substantially improved compressive strength and flexural strength and a Knoop microhardness which is more than twice as high as that of the previously known ethylene imine compounds (see Table 2).

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Table 2

Comparative values of the physical properties of

Compressive strength (24 hours / H20 / 37 ° C) in N mm "2 Flexural strength in N mm-2

Knoop microhardness in kpmm "2 with standard deviation Thermal expansion in ppm Processing width in min / sec Hardening time in min / sec

Two-component systems according to the Swiss

Invention DOS 2 404 380 Patent No. 484 977

97-103 109

21.37 + 0.85 5

3'24 "

71-78

5'36 "

State of the art 60-68 92

9.40 + 0.62 64

3'00 "

Another advantage of the two-component systems used according to the invention is that, despite the extended processing range of the mixed paste, a considerably shorter curing time is achieved compared to the two-component systems already known (see Table 2).

Of course, the invention can be modified in many different ways, and the example below is only intended to illustrate the invention.

example

193 ml (3.75 mol) of ethyleneimine and 350 mg of tributylamine were placed in a 1.5 liter capacity sulphonation flask equipped with a dropping funnel, thermometer, cooler and calcium chloride tube, mixed with a magnetic stirrer and preheated to 50.degree. 295 g (0.5 mol) of 2,2-bis (4'-β-hydroxyethoxy-3 ', 5'-dichlorophenyl) propane bis-cro-tonate were dissolved in 500 ml of benzene and removed from the dropping funnel within Added dropwise to the reaction mixture for 15 minutes. The inside temperature was kept at 48-52 ° C. The reaction proceeded without noticeable development of exothermic heat. The reaction mixture was stirred for a further 15 minutes at 50 ° C., then cooled, and stirring was continued for 4 days.

The IR spectrum of the crude product obtained differed from the educt by the following changes:

- The band at 1715 cm-1 (C = C-COO) had been shifted to 1730 cm-1 because of the missing conjugation.

- The band at 1660 cm-1 (C = C double bond) had completely disappeared.

The mixture was evaporated in the chapel on a rotary evaporator and then dried in a high vacuum.

The solvent distillate collected in a rotary evaporator and in the cold trap under high vacuum still contained relatively large amounts of ethylene imine, which was polymerized to render it harmless by adding acetic acid.

335.3 g (= 99% of theory) of 2,2-bis (4'-ß-hydroxyethoxy-3 ', 5'-dichlorophenyl) -pro-20 pan-bis-ß-ethylenimino- remained in the rotary evaporator. butyrate in the form of a slightly yellowish oil.

To prepare a paste suitable for the manufacture of semi-permanent crowns and bridges, 10 g of silica gel with a grain size of less than 0.08 mm, which had been treated with 25 2% silane containing amino groups, were incorporated into 100 g of the ethyleneimine compound obtained. The paste was additionally colored with pigments in order to obtain a tooth-colored product as possible and provided with an ultraviolet light protective agent in order to increase the color resistance.

The second component consisted of a mixture of 9 parts of p-toluenesulfonic acid methyl ester and 1 part of p-toluenesulfonic acid ethyl ester.

The best results were obtained by applying egg-35 drops (35 to 38 mg) of catalyst to 800 mg of the paste obtained.

To produce a semi-permanent crown or bridge, the paste mixed with the catalyst was preferably applied by syringe to an alginate or sili-40 which had been obtained from the intact teeth prior to preparation, whereupon the impression was made without delay on the model of the prepared teeth of the patient was reset.

After the start of hardening (approx. 3 minutes after 45 hours of mixing), the impression together with the hardened molded body was removed from the model and left to harden for another 10 minutes. The procedure could be accelerated by placing the molded body in hot water.

The semi-permanent crown or bridge was then completed in the usual way by removing the excess.

Claims (10)

630 253 2 PATENT CLAIMS 1. Two-component system for the production of tooth - the first component is an ethyleneimine compound of the all-technical form, characterized in that the general formula .0 — Y_0 0 — Y_ 0. contains in which X is an alkylidene, cycloalkylidene or an SO 2 radical, Y is a divalent organic radical and Z is an acyl radical of a carboxylic acid which is substituted by an ethyleneimino group, and n is 1 to 4 and m is 0 to 4 and the second component contains a hardener. 2. Two-component system according to claim 1, characterized in that, X is the isopropylidene or S02 group. Z- 0- Y_0 corresponds. 3. Two-component system according to claim 2, characterized in that Y is the ethylene group and that the acyl radical Z is preferably derived from an aliphatic carboxylic acid having 1 to 6 carbon atoms, which optionally contains aromatic radicals. 4. Two-component system according to one of the patent claims 20 to 1, characterized in that the ethyleneimine compound in the second benzene ring is also substituted with up to 4 chlorine atoms, and z. B. the general formula 0-Y-.0. 5. Two-component system according to claim 4, characterized in that the ethyleneimine compound is 2,2-bis (4'-ß-hydroxyethoxy-3 /, 5'-dichlorophenyl) propane-bis-ß-ethyleneiminobutyrate. 6. Two-component system according to claim 1, characterized in that the first component also contains packing, in particular those whose surface is silanated. 7. Two-component system according to claim 1, characterized in that the hardener is a sulfonic ester. 8. Use of the two-component system according to claim 35 for the production of artificial teeth, dental prostheses, models or dental prostheses outside the oral cavity. 9. Use according to claim 8 of a two-component system according to one of claims 2 to 7. 40 10. Use according to claim 9 for the production of semi-permanent or definitive crowns and bridges.