DE10329359A1 - Addition-crosslinking organopolysiloxane composition useful as a dental material (e.g. in bite registration materials) achieves a high final hardness and high elasticity - Google Patents

Abstract

An addition-crosslinking organopolysiloxane-based molding composition achieving a high final hardness and useful as a dental material is especially of 2-component form and can be completely free of short-chain, terminal-functional polysiloxanes and also of reinforcing fillers. An addition-crosslinking organopolysiloxane-based molding composition achieving a high final hardness and useful as a dental material is especially of 2-component form and comprises by weight: (A) an organopolysiloxane with 2 vinyl end groups (1-90, especially 5-20, %); (B) a low mol. wt. vinyl- and ethoxy-group-containing QM resin (1-90, especially 5-20, %); (C) an organohydrogenpolysiloxane with >=2 SiH groups (1-10%); (D) a catalyst accelerating the hydrosilylation reaction (0.005-2, especially 0.01-1, %); (E) non-reinforcing fillers (1-90, especially 20-70, %); (F) moisture binder (0-10%); (G) further additives and auxiliaries (0-10%); (H) colorant (0-2, especially 0.5-1, %); and (I) inhibitors (0-1, especially 0-0.1, %).

Description

The The invention relates to addition-crosslinking silicone impression materials based on Polyorganosiloxanes that have a high final hardness and are special are suitable as dental materials.

in the Dental area, i.e. in dental and dental applications, it is often desirable to use materials high final hardness use. For example, hard materials are considered temporary and permanent filling materials, Crown and bridge materials, Cements and preferably used as materials for bite registration.

The bite registration materials mentioned as preferred by the dentist the dentist to fix the correct position from upper to lower jaw to each other used. This position of the upper and lower jaw to each other is then transferred to the model in the dental laboratory. This model is the basis for further work in the dental laboratory, the requirements are correspondingly high precision of this model.

On A bite registration material has the following requirements:

1) High final hardness and low elasticity

in the essentially determines the final hardness the precision a bite registration, because of this high final hardness in the transfer on the model in the dental laboratory vertical and horizontal Prevents shifts. Also the further processing of the bite registration with the milling machine and the scalpel is simplified by the high final hardness.

2) Long processing time with a short overall stay in the patient's mouth

The Processing time should be long enough to cover an entire To be able to cover the patient's row of teeth with the material and nevertheless an even bite registration to achieve (at least 30 seconds). The time of maximum intercuspation should also if possible be short to avoid displacement of the jaw during the setting phase. The total length of time of the material in the patient's mouth from The start of mixing should not exceed 90 seconds.

3) Fracture behavior

Nice excess material should be in the patient's mouth can be canceled to be able to check the correct bite registration.

4) Easy to use

The Dosing and mixing should be done for the dentist preferably simply and without great effort possible his. In particular, the material is said to be thixotropic to be a downflow to be excluded from the row of teeth, but it should be under the discharge pressure flow easily can.

5) Dimensional stability

The Bite registration material should be dimensionally stable, i.e. not shrink to after transportation from dental practice to dental Laboratory to enable the exact reduction of the upper and lower jaw.

6) Storage stability

The desired Characteristics of a bite registration material should also have one longer Period remain stable.

From the DE 4 122 310 EP 0 522 341 For example, a transparent silicone impression material is known which can be used as a bite registration material and has a final hardness above 70 Shore A by using short-chain, vinyl-terminated polyorganosiloxanes of the general formula CH ₂ = CH-SiR ₂ O- (SiR ₂ O) _n -SiR ₂ -CH = CH ₂ with n = 10-20 and achieved by adding a novel compound made of vinyl-stopped polyorganosiloxane and reinforcing filler. However, due to its elastic properties and insufficient final hardness, such a material is unsuitable for producing a precise bite registration.

In the EP 0 894 117 describes the production of addition-curing silicone impression materials with a very high final hardness in the Shore D range and with a very high modulus of elasticity. A very short-chain, vinyl-stopped polyorganosiloxane of the general formula CH ₂ = CH-SiR ₂ O- (SiR ₂ O) _n -SiR ₂ -CH = CH ₂ with n = 21-69 is used in combination with a vinyl-rich QM resin and reinforcing fillers. In addition to the high final hardness, the total length of stay in the patient's mouth of 90 seconds is advantageous.

In WO 99/09934 are curable Masses for presented dental applications that have a very high final hardness short setting times. A new type is used Compound class, the silane dendrimers, despite the high content on functional groups the two mentioned, positive for dental materials Should have properties. The disadvantage is that the synthesis the dendrimers are very complex is. Big amount of of those connections that are for the production of dental impression materials, especially for very hard ones Bite registration materials, needed Need to become very complex getting produced.

• - Erhöhung des Füllstoffgehaltes der Massen
• – Einsatz von verstärkenden Füllstoffen bzw. Compounds, die solche Füllstoffe enthalten
• – Erhöhung des Funktionalitätsgrades der reaktiven Bestandteile der Massen
• – Erniedrigung der Kettenlänge der reaktiven Bestandteile der Massen

To achieve the desired high final hardness, the following solutions are always used in the above-mentioned patents and thus according to the state of the art:

• - Increase the filler content of the masses
• - Use of reinforcing fillers or compounds that contain such fillers
• - Increasing the functionality of the reactive components of the masses
• - Reduction of the chain length of the reactive constituents of the masses

By the increase the filler content and through the use of reinforcing fillers as well as compounds made from polyorganosiloxanes and reinforcing fillers are manufactured, the mechanical properties of the cured silicone materials improved, especially the elasticity of the material is increased. This is for the preferred application of the silicone impression material for bite registration thereby possible vertical and horizontal shifts in the reduction in dental laboratory disadvantage. In addition, such raw materials are known to increase the viscosity of silicone impression materials so that the effort required to convey the Materials from the usual double cartridge systems with static mixer very much gets big. The choice of the appropriate mixing tip for conveying the material is the Therefore, users on the larger mixing tips larger volume established.

By the use of vinyl-containing polyorganosiloxanes, which not only terminal, but also lateral functionalities, so Have vinyl groups, although the final hardness of the silicone impression materials elevated but they have the big one Disadvantage that they also have vicinal, i.e. neighboring vinyl groups contain. It is known from the prior art that vicinal Vinyl groups inhibit the reaction time of the hydrosilylation reaction act under precious metal catalysis. The bite registration materials should but especially through a maximum residence time of the material mark in the patient's mouth from 90 seconds. That goal will so not achieved.

Very short-chain vinyl-terminated polyorganosiloxanes of the general formula CH ₂ = CH-SiR ₂ O- (SiR ₂ O) _n -SiR ₂ -CH = CH ₂ with n = 0-6 and R = identical or different monovalent, unsaturated, optionally substituted Hydrocarbons (mostly methyl groups) are from the DE-A-2 646 726 known as inhibitors for regulating the rate of crosslinking in the reaction of addition-crosslinking silicone materials. Even with very short-chain functional polyorganosiloxanes, a very high final hardness can be achieved, but an extension of the setting time, which is undesirable for use as a bite registration material, and thus the total length of stay of the material in the patient's mouth is accepted.

• a) Organopolysiloxane mit zwei oder mehr Vinyl-Gruppen im Molekül (endständig und/oder seitenständig) und Viskositäten im Bereich von 100–350.000 mPa·s
• b) Organopolysiloxane der allgemeinen Formel CH₂= CH-SiR₂O- (SiR₂O) _n-SiR₂-CH=CH₂ mit R= gleiche oder verschiedene einwertige, ungesättigte, gegebenenfalls substituierte Kohlenwasserstoffe (meistens Methyl-Gruppen) n= 10-69
• c) Niedermolekulare vinyl- und ethoxygruppenhaltige QM-Harze
• d) Katalysatoren zur Beschleunigung der Additionsvernetzung (Hydrosilylierung)
• e) Organohydrogenpolysiloxane mit mindestens zwei SiH-Gruppen im Molekül
• f) Verstärkende Füllstoffe
• g) Nicht verstärkende Füllstoffe
• h) Farbstoffe
• i) Inhibitoren.

Dental impression materials and bite registration materials based on polyorganosiloxanes have been known for many years (see, for example, RGCraig: Restaurative Dental Materials, CV Moosbe-Comp., St. Louis 1980). According to the state of the art, the composition of these materials essentially consists of the following raw materials:

• a) Organopolysiloxanes with two or more vinyl groups in the molecule (terminal and / or side) and viscosities in the range of 100-350,000 mPa · s
• b) Organopolysiloxanes of the general formula CH ₂ = CH-SiR ₂ O- (SiR ₂ O) _n -SiR ₂ -CH = CH ₂ with R = same or various monovalent, unsaturated, optionally substituted hydrocarbons (mostly methyl groups) n = 10-69
• c) Low molecular weight vinyl and ethoxy group-containing QM resins
• d) catalysts for accelerating the addition crosslinking (hydrosilylation)
• e) Organohydrogenpolysiloxanes with at least two SiH groups in the molecule
• f) reinforcing fillers
• g) Non-reinforcing fillers
• h) dyes
• i) inhibitors.

To Such addition-crosslinking materials exist in the prior art from two components (A and B component or catalyst and called base component), which are kept separate Need to become and after the homogeneous mixing (mixing ratio usually 1: 1) in crosslink a noble metal catalyzing hydrosilylation reaction. The two components are mixed homogeneously either by Strand length metering and manual mixing or over a double cartridge system with static mixer.

On such double cartridge system is for example from the company Mixpack available and contains two separate chambers, each with a volume of 25 ml. Differently dimensioned mixing tips as static mixers are for the different viscosities and consistencies of the silicone impression materials available. The ones available on the market Bite registration materials are also from those described above Establish- of such high viscosity, that a promotion only by a big one mixing tip without being too big Exertion of force comes into question.

• – Erreichen einer hohen Endhärte im Shore-D-Bereich und eines hohen Elastizitätsmoduls
• – leichte Verarbeitbarkeit für den Anwender hinsichtlich Viskosität und Thixotropie
• – leichte Förderbarkeit und homogene Mischung des Materials aus den handelsüblichen Doppelkartuschen-Systemen auch durch kleinere Mischkanülen als bisher marktüblich, dadurch auch Materialersparnis
• – schnelleres Abbindeverhalten, die Gesamtverweildauer des Materials im Mund des Patienten sollte maximal 90 Sekunden, bevorzugt maximal 80 Sekunden ab Mischbeginn betragen. Die Verarbeitungszeit sollte dennoch mindestens 30 Sekunden betragen
• – gute Bearbeitbarkeit mit Fräse und Skalpell, ein gezieltes Abbrechen des Materials schon im Mund des Patienten sollte möglich sein
• – gute Lagerstabilität in der üblichen Handelsverpackung.

The aim of this invention is therefore to provide addition-crosslinking 2-component silicone impression materials for use in the dental field, preferably for use as bite registration materials, which combine the following advantageous properties:

• - Achieving a high final hardness in the Shore D range and a high modulus of elasticity
• - Easy processability for the user with regard to viscosity and thixotropy
• - Easy conveyability and homogeneous mixing of the material from the commercially available double cartridge systems, even through smaller mixing tips than previously customary on the market, which also saves material
• - faster setting behavior, the total residence time of the material in the patient's mouth should be a maximum of 90 seconds, preferably a maximum of 80 seconds from the start of mixing. The processing time should still be at least 30 seconds
• - Good workability with a milling cutter and scalpel, a targeted breaking off of the material in the patient's mouth should be possible
• - Good storage stability in the usual retail packaging.

• a) 1-90 Gew.% bevorzugt 5-20 Gew.% Organopolysiloxane mit zwei terminalen Vinyl-Gruppen
• b) 1-90 Gew.% bevorzugt 5-20 Gew.% niedermolekulares, Vinyl- und Ethoxy-Gruppen enthaltendes QM-Harz
• c) 1-10 Gew.% Organohydrogenpolysiloxane mit mindestens zwei SiH-Gruppen im Molekül
• d) 0,005-2 Gew.% bevorzugt 0,01-1 Gew.% Katalysatoren zur Beschleunigung der Hydrosilylierungsreaktion
• e) 1-90 Gew.% bevorzugt 20-70 Gew.% nicht verstärkende Füllstoffe
• f) 0-10 Gew.% Feuchtigkeitsbinder
• g) 0-10 Gew.% weitere Additive und Hilfsmittel
• h) 0-2 Gew.% bevorzugt 0,5-1 Gew.% Farbstoffe
• i) 0-1 Gew.% bevorzugt 0-0,1 Gew.% Inhibitoren

This goal is achieved with an addition-crosslinking 2-component silicone impression material of the following composition, surprisingly, the use of very short-chain, terminal-functional polyorganosiloxanes and reinforcing fillers can be completely dispensed with. All information is to be understood in percent by weight based on the total mass of the material (i.e. catalyst and base component).

• a) 1-90% by weight, preferably 5-20% by weight, of organopolysiloxanes with two terminal vinyl groups
• b) 1-90% by weight, preferably 5-20% by weight, of low-molecular weight QM resin containing vinyl and ethoxy groups
• c) 1-10% by weight of organohydrogenpolysiloxanes with at least two SiH groups in the molecule
• d) 0.005-2% by weight, preferably 0.01-1% by weight, of catalysts for accelerating the hydrosilylation reaction
• e) 1-90% by weight, preferably 20-70% by weight, of non-reinforcing fillers
• f) 0-10% by weight of moisture binder
• g) 0-10% by weight of other additives and auxiliaries
• h) 0-2% by weight, preferably 0.5-1% by weight, of dyes
• i) 0-1% by weight, preferably 0-0.1% by weight, of inhibitors

at The organopolysiloxanes a) are known vinyl-end-stopped Polydimethylsiloxanes with viscosities in the range of 100-165,000 mPa.s, preferably in the range of 200-10,000 mPa · s.

The QM resins b) according to the invention are described in W.Noll, Chemistry and Technology of Silicones, Verlag Chemie, Weinheim, 2nd edition 1968 and contain the tetrafunctional SiO _4/2 as Q units and the monofunctional R ₃ as M units SiO _1/2 , where R can be vinyl, methyl, ethyl, phenyl. It can also contain trifunctional RSiO _3/2 as T units and difunctional R ₂ SiO _2/2 as D units. The QM resins used have viscosities of 150-65,000 mPa · s, preferably 150-3,000 mPa · s and vinyl contents of 0.2-8mmol / g, preferably 0.2-2mmol / g.

The compounds according to c) contain reactive SiH groups which build up the polymer in an addition reaction with noble metal catalysis with the compounds a) and b). The compounds used are polymethylhydrogensiloxanes with an SiH content in the range from 0.5 to 15 mmol / g, preferably from 2-10 mmol / g. The noble metal catalyst d) is preferably a platinum complex; platinum-siloxane complexes, as already described in, are particularly suitable US-A-3,715,334 . US-A-3,775,352 and US-A-3,814,730 are described.

The non-reinforcing fillers according to e) have a BET surface area of up to 50m ² / g, these include quartz, cristobalite, diatomaceous earth, diatomaceous earth, calcium carbonate, talc, zeolite, sodium aluminum silicate, metal oxide and glass powder. These fillers can be made hydrophobic by surface treatment.

To the state of the art as moisture binder f) zeolites, anhydrous aluminum sulfate, Molecular sieves, diatomaceous earth and blue gel are used.

at the other additives and auxiliaries g) are surfactants, Emulsifiers, stabilizers, thixotropic agents and hydrogen absorbers. In the case of dyes h), which may be used to differentiate Base and catalyst component and to control the homogeneity of the mixture can be used are inorganic and / or organic color pigments, who also solved can be used in polyorganosiloxanes or other solvents.

To control the reactivity it may be necessary to use inhibitors i). Such inhibitors are known and, for example, in US-A-3,933,880 described. As a rule, these are acetylenically unsaturated alcohols or vinyl group-containing, aliphatic or cyclic poly-, oligo- and disiloxanes.

The Masses are preferably formulated in two components to ensure storage stability. The total noble metal catalyst content d) is in the catalyst component, the total SiH compound content c) is in the second, spatial component separate from the first component to accommodate the base component. By mixing the two components, the masses harden as hydrosilylation known addition reaction.

The volume ratios of the two components can 10: 1 to 1:10. Volume mixing ratios are particularly preferred of 1: 1, 4: 1 and 5: 1 (base to catalyst component).

The explain the following examples the invention closer. All parts specified are to be understood as parts by weight.

example 1

In a mixing container 113 parts of vinyl-terminated polydimethylsiloxane with a Viscosity of 200 mPas, 85 parts of a vinyl group containing both terminal and pendant groups Polydimethylsiloxane, 113 parts of a compound made of polyorganosiloxane and hydrophobicized fumed silica, 11 parts of a platinum catalyst and 480 parts of a surface treated Cristobalits submitted and mixed homogeneously for 30 minutes. The mixture will then Degassed in a vacuum for 15 min.

Example 2

77 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 200 mPa · s, 49 parts of a polyorganosiloxane containing both terminal and pendant vinyl groups, 100 parts of a compound of polyorganosiloxane and hydrophobicized pyrogenic silica, 94 parts of a SiH crosslinker are mixed in a mixing container an SiH content of 9.3 mmol / g, 3 parts of dye and 480 parts of an upper submitted surface-treated cristobalits and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 min.

Example 3

50 Parts of the catalyst component described in Example 1 and 50 parts of the base component described in Example 2 are funded from a double cartridge and over a static mixer homogeneously mixed. Delivery from the double cartridge requires a lot of effort. A cured molded body is also obtained a final hardness of 88 Shore A. The modulus of elasticity is based on EN ISO 178 determined in the bending test to 16 MPa (dimensions of the test specimens 25mm, 5mm, 5mm, cuboid).

Example 4

77 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 200 mPas, 26 parts of a polydimethylsiloxane containing both terminal and pendant vinyl groups, 326 parts of a compound composed of polyorganosiloxane and hydrophobized pyrogenic silica, 9 parts of a platinum catalyst and 11 parts of a surface-treated silica with a BET surface area of 170-200 m ² / g were introduced and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 min.

Example 5

70 parts of vinyl-terminated polydimethylsiloxane with a viscosity of 200 mPas, 24 parts of a polydimethylsiloxane containing both terminal and pendant vinyl groups, 300 parts of a compound composed of polyorganosiloxane and hydrophobized pyrogenic silica, 39 parts of a SiH crosslinker are mixed in a mixing container an SiH content of 7.3 mmol / g, 1 part of dye and 19 parts of a surface-treated silica with a BET surface area of 170-200 m ² / g and mixed homogeneously for 30 minutes. The mixture is then degassed in vacuo for 15 min.

Example 6

50 Parts of the catalyst component described in Example 4 and 50 parts of the base component described in Example 5 are funded from a double cartridge and over a static mixer homogeneously mixed. Delivery from the double cartridge requires a lot of effort. A cured molded body is also included a final hardness from 66 Shore A. The modulus of elasticity is based on EN ISO 178 determined in the bending test at approx. 5 MPa (dimensions of the test specimens 25mm, 5mm, 5mm, cuboid).

Example 7

In a mixing container 75 parts of vinyl-terminated polydimethylsiloxane with a Viscosity of 200 mPas, 64 parts of a QM quartz containing vinyl and ethoxy groups with a viscosity of 2,000 mPas and a vinyl content of 1.4mmol / g, 214 parts of a surface-treated Cristobalits, 44 parts of calcium carbonate, 5 parts of a platinum catalyst, 1 part of a zeolite and 1 part of a polyether siloxane as a thixotropic agent submitted and mixed homogeneously for 30 minutes. The mixture is then 15 min degassed in vacuum.

Example 8

In a mixing container 26 parts of vinyl-terminated polydimethylsiloxane with a Viscosity of 200 mPas, 51 parts of a QM quartz containing vinyl and ethoxy groups with a viscosity of 2,000 mPas and a vinyl content of 1.4 mmol / g, 198 parts of a surface-treated Cristobalits, 70 parts calcium carbonate, 59 parts of a SiH crosslinker mixture with an average SiH content of 7.8 mmol / g, 7 parts of a dye, 1 part of a zeolite, 1 part of a polyether siloxane as a thixotropic agent and 0.1 parts of an inhibitor mixture and 30 minutes homogeneously mixed. The mixture is then degassed in vacuo for 15 min.

Example 9

50 Parts of the inventive catalyst component described in Example 7 and 50 parts of the base component according to the invention described in Example 8 are conveyed from a double cartridge and via a static mixer homogeneously mixed. The funding only a small amount of effort is required from the double cartridge and is also possible from smaller mixing tips. You get one cured moldings with a final hardness von 51 Shore D. The modulus of elasticity is based on EN ISO 178 in Bending test determined to 126 MPa (dimensions of the test specimens 25mm, 5mm, 5mm, cuboid).

Example 10 (comparative example)

On commercial addition-curing silicone material for the Bite registration will follow instructions of the manufacturer from the double cartridge via a static mixer mixed. The effort required is big. You get a cured one moldings with a final hardness of 43 Shore D. The modulus of elasticity is based on EN ISO 178 determined in the bending test to 61 MPa (dimensions of the test specimens 25mm, 5mm, 5mm, cuboid).

Example 11 (comparative example)

On second commercially available addition-curing silicone material for the bite registration as directed of the manufacturer from the double cartridge via a static mixer mixed. The one needed It takes a lot of effort. You get a cured one moldings with a final hardness of 45 Shore D. The modulus of elasticity is based on EN ISO 178 determined in the bending test to 59 MPa (dimensions of the test specimens 25mm, 5mm, 5mm, cuboid).

From the examples above it is clear that the addition-crosslinking silicone impression material according to the invention, which can preferably be used for bite registration, clearly outperforms the commercially available materials in its properties important for the use as bite registration - final hardness, modulus of elasticity and ease of delivery from double cartridges is. The results are summarized again in Table 1. Table 1

Claims (3)

Addition-crosslinking silicone impression materials based on polyorganosiloxanes, which have a high final hardness and are particularly suitable as dental materials, in particular addition-crosslinking 2-component silicone impression material with the following composition: a) 1-90% by weight, preferably 5-20%. % Organopolysiloxanes with two terminal vinyl groups b) 1-90% by weight, preferably 5-20% by weight of low molecular weight QM resin containing vinyl and ethoxy groups c) 1-10% by weight of organohydrogenpolysiloxanes with at least two SiH- Groups in the molecule d) 0.005-2% by weight, preferably 0.01-1% by weight, catalysts for accelerating the hydrosilylation reaction e) 1-90% by weight, preferably 20-70% by weight, of non-reinforcing fillers f) 0-10% by weight of moisture binder g) 0-10% by weight of further additives and auxiliaries h) 0-2% by weight, preferably 0.5-1% by weight of dyes i) 0-1% by weight, preferably 0- 0.1% by weight inhibitors. Addition-curing 2-component silicone impression material Claim 1, characterized in that the catalyst component (first component) the total precious metal catalyst content comprises and the base component (second component) by the first component spatially is separated, includes the entire SiH compound content. Addition-curing impression material according to one of the Expectations 1 or 2, characterized in that the volume ratio of two components (basic component: Catalyst component) is 10: 1 to 1:10, preferably 1: 1, 4: 1 or 5: 1.