Polysiloxane compound and dental materials that can be prepared from it

Abstract

The invention relates to a polysiloxane compound comprising specific siloxane units, curable dental materials comprising one or more than one polysiloxane compound according to the invention, cured dental materials obtainable from the curable dental materials according to the invention, a method for preparation of polysiloxane compounds according to the invention, a method for preparing curable polysiloxane compounds according to the invention and a method for preparing cured dental materials according to the invention.

Claims

1. A polysiloxane compound comprising: (A) one, two, three or more than three in each case structurally identical first siloxane units selected from the group consisting of siloxane units of the general formula (I) ##STR00040## wherein for the structural units A, Q, X and R.sup.1 in each of the structurally identical first siloxane units independently of one another the following applies: A denotes H or CH.sub.3, Q denotes a link group bearing substituent X, R.sup.1 denotes an alkyl radical with a total of 1 to 4 carbon atoms and X is selected from the group consisting of branched, saturated, unsubstituted alkyl radical with a total of 7 to 18 carbon atoms, unbranched, saturated, unsubstituted alkyl radical with a total of 7 to 18 carbon atoms, unsubstituted or alkyl substituted aryl radical with a total of 10 to 18 carbon atoms, wherein the alkyl substituent in the alkyl substituted aryl radical is branched and saturated or unbranched and saturated and Z(CO)R.sup.2, wherein herein for the structural units Z and R.sup.2 independently of one another and independently of what the structural units A, Q and R.sup.1 denote the following applies: Z denotes O, S or NH, preferably O and R.sup.2 is selected from the group consisting of branched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, unbranched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, and unsubstituted or alkyl substituted aryl radical with a total of 9 to 18 carbon atoms, wherein the alkyl substituent in the alkyl substituted aryl radical is branched and saturated or unbranched and saturated, wherein b denotes 0, 1 or 2 and a denotes 3-b.

2. The polysiloxane compound, according to claim 1, comprising: (A) one, two, three or more than three in each case structurally identical first siloxane units selected from the group consisting of siloxane units of the general formula (Ia) ##STR00041## wherein for the structural units A, X and R.sup.1 in each of the structurally identical first siloxane units independently of one another the following applies: A denotes H or CH.sub.3, R.sup.1 denotes an alkyl radical with a total of 1 to 4 carbon atoms and X is selected from the group consisting of branched, saturated, unsubstituted alkyl radical with a total of 7 to 18 carbon atoms, unbranched, saturated, unsubstituted alkyl radical with a total of 7 to 18 carbon atoms, unsubstituted or alkyl substituted aryl radical with a total of 10 to 18 carbon atoms, wherein the alkyl substituent in the alkyl substituted aryl radical is branched and saturated or unbranched and saturated and Z(CO)R.sup.2, wherein herein for the structural units Z and R.sup.2 independently of one another and independently of the meaning of the structural units A and R.sup.1 the following applies: Z denotes O, S or NH, and R.sup.2 is selected from the group consisting of branched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, unbranched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, and unsubstituted or alkyl substituted aryl radical with a total of 9 to 18 carbon atoms, wherein the alkyl substituent in the alkyl substituted aryl radical is branched and saturated or unbranched and saturated, wherein b denotes 0, 1 or 2 and a denotes 3-b and (B) one, two, three or more than three, in each case structurally identical second siloxane units, which are structurally different from the first siloxane unit.

3. The polysiloxane compound according to claim 1, comprising: (A) one, two, three or more than three in each case structurally identical first siloxane units selected from the group consisting of siloxane units of the general formula (Ic) ##STR00042## wherein for the structural units A, R.sup.1 and R.sup.2 in each of the structurally identical first siloxane units independently of one another the following applies: A denotes H or CH.sub.3, R.sup.1 denotes an alkyl radical with a total of 1 to 4 carbon atoms, and R.sup.2 is selected from the group consisting of branched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, unbranched, saturated, unsubstituted alkyl radical with a total of 6 to 18 carbon atoms, and unsubstituted or alkyl substituted aryl radical with a total of 9 to 18 carbon atoms, wherein the alkyl substituent in the alkyl-substituted aryl radical is branched and saturated or unbranched and saturated, wherein b denotes 0, 1 or 2 and a denotes 3-b and (B) one, two, three or more than three, in each case structurally identical second siloxane units, which are structurally different from the first siloxane unit.

4. The polysiloxane compound according claim 1, wherein R.sup.2 is selected from the group consisting of: 1-naphthyl, 4-tert.-butyl-1-phenyl, and n-undecanyl.

5. A curable dental material comprising: one or more than one polysiloxane compound according to claim 1, and one or more than one compound different from the polysiloxane compound according to claim 1.

6. The curable dental material according to claim 5, further comprising one, two or more than two or all substances from the group consisting of: dental organic filler particles, which are radiopaque and/or nanoscale, dental inorganic filler particles which are radiopaque and/or nanoscale, dental organically surface-modified inorganic filler particles, which are radiopaque and/or nanoscale, rheological agents, polymerisation initiators, photoinitiators, chemical compounds as catalysts or components of catalyst systems, colourants, dye pigments, stabilisers, daylight stabilisers, inhibitors, activators, molecular weight modifiers, preservatives, surface-active substances, microbicides, bactericides, organic radically polymerisable monomers, which are not polysiloxanes according to the invention, for conversion with the polysiloxane compound according to the invention, organic polymers and oligomers and compounds with high molecular weights, plasticisers, thickeners and dental medicinal products.

7. The cured dental material, obtainable from a curable dental material according to claim 5 by means of polymerisation of the polysiloxane compound contained in the dental material and possibly further polymerisable components contained in the dental material.

8. The polysiloxane compound according to claim 1, for application in a therapeutic procedure, wherein a polysiloxane compound according to claim 1 is used as a polymerisable component of a curable dental material.

9. The polysiloxane compound according to claim 1, for specific application in a therapeutic procedure for temporary or permanent filling of a dental cavity or in a therapeutic procedure as a dental filling material, dental lining material, dental adhesive (bonding), as a flowable composite material (flow material), as a fissure sealant, as a crown material, as an inlay and/or onlay, as a bridge material and/or as a core build-up material.

10. A kit, comprising: one, two or more than two curable dental materials according to claim 5 and/or one, two or more than two base pastes and one, two or more than two catalyst pastes, wherein the one base paste or the two or more than two base pastes in each case and independently of one another comprises or comprise one or more than one polysiloxane compound according to claim 1.

11. A method for preparing a polysiloxane compound, comprising the following steps: preparing or providing an intermediate polysiloxane compound comprising (A.sub.p) one, two, three or more than three in each case structurally identical first intermediate siloxane units selected from the group consisting of siloxane units of the general formula (I.sub.p) ##STR00043## wherein for the structural units A, Q, X.sub.p and R.sup.1 in each of the structurally identical first siloxane units independently of one another the following applies: A denotes H or CH.sub.3, Q denotes a link group bearing the substituent X.sub.p, R.sub.1 denotes an alkyl radical with a total of 1 to 4 carbon atoms and X.sub.p for a reactive group wherein b denotes 0, 1 or 2 and a denotes 3-b, conversion of the intermediate polysiloxane compound in one or more steps through reaction of the reactive group X.sub.p, so that the polysiloxane compound according to claim 1 is formed.

12. The method for preparing a curable dental material comprising the steps of: providing or preparing one or more polysfoxane compounds according to claim 1, providing or preparing one, more additives, preparing a single-component or multi-component system comprising the provided or prepared polysiloxane compound(s) and the provided or prepared substance(s) and optionally, additional substances, wherein multi-component systems substances that trigger a polymerisation are distributed over separate components such that a polymerisation of the polysiloxane compounds is triggered through mixing of said components.

13. A method for preparing a cured dental material comprising the following steps: providing or preparing a curable dental material according to claim 5, polymerisation of the polysiloxane compound contained in the dental material and possibly further polymerisable components contained in the dental material.

14. A method comprising of: Application of a curable dental material according to claim 5 on the tooth substance or the dental tissue of a patient or on a dental restoration.

Description

A) PREPARATION AND PROPERTIES OF POLYSILOXANE COMPOUNDS

(1) 1.) Example Synthesis of an Intermediate Polysiloxane Compound with Reactive Polar Group (See EP 1 685 182 B1) (Polysiloxane A)

(2) 1.1) Synthesis of a Monomeric Silane Unit (See EP 1 685 182 B1, Example 3):

(3) To the pre-mixed material of 100 g (0.402 mol) 3-glycidyloxypropyldiethoxymethylsilane under dry atmosphere (oxygen) an addition catalyst, BHT as the stabilizer and then 38.05 g (0.442 mol) methacryclic acid were added in drops with agitation at approximately 80 C. (approximately 24 hours) (see Diagram (c) top, or paragraph [0048] in EP 1 685 182 B1). The conversion was monitored through the decrease in the carboxylic acid concentration by means of acid titration and the epoxy conversion by means of Raman spectroscopy/epoxy titration. The bands characteristic of the epoxy group were detected in the Raman spectrum at 1256 cm.sup.1. The epoxy or carboxylic acid conversion was >99% or >88% (a result of the excess carboxylic acid).

(4) 1.2) Hydrolysis or Condensation or the Monomeric Silane Unit to an Intermediate Polysiloxane Compound (Polysiloxane A) (See Diagram (d) Top, or EP 1 685 182 B1, Example 6):

(5) Following addition of ethyl acetate (1 000 ml/mol monomeric silane unit) and H.sub.2O for hydrolysis with HCl as catalyst to the synthesised monomeric silane unit agitation took place at 30 C. The progress of the hydrolysis was monitored by water titration. The working up took place after a number of days' agitation at 30 C. through repeated extraction with aqueous NaOH and subsequent extraction with water and filtration via a hydrophobic filter. Following addition of BHT rotary evaporation initially took place at 40 C. and then the solvent residues (e.g. water and alcohol residues) were extracted under vacuum by means of an oil pump, in order to remove the alcohol and water residues. The result was a liquid resin with a viscosity of 4.5 Pa.Math.s at 25 C. (highly dependent upon the precise hydrolysis and working up conditions).

(6) The intermediate polysiloxane compound referred to as polysiloxane A serves in the following on the one hand as a reference compound in a comparison of physical properties (see Table 2 below) and on the other as a starting compound for further conversion to a polysiloxane compound according to the invention.

(7) 2) Preparation of Polysiloxane Compounds According to the Invention (Polysiloxanes B, C, D, E, and F):

(8) 2.1) Preparation of a Polysiloxane Compound According to the Invention (Polysiloxane B) by Converting Polysiloxane a with Naphthoyl Chloride:

(9) To a premixed material of 15 mmol polysiloxane A and 1.1 eq triethylamine in toluene under dry atmosphere and ice cooling (4 C.) a solution of 1.1 eq. naphthoyl chloride in toluene was slowly added in drops. Once addition was complete the solution was agitated at room temperature. The conversion was monitored via the reduction in the band characteristic of the OH group by IR spectroscopy; the band characteristic of the OH group was detected under IR at 3200-3400 cm.sup.1. For working up the solution was initially extracted with 1M HCl and then washed twice with water. Following drying of the organic phase over magnesium sulphate and removal of the solvent under vacuum a slightly yellowy flowable resin with a viscosity of 17.5 Pa.Math.s at 25 C. was obtained. Table 2 provides a comparison of physical properties.

(10) 2.2) Preparation of a Polysiloxane Compound According to the Invention (Polysiloxane C) by Converting Polysiloxane a with Tert-Butylbenzoyl Chloride:

(11) To a pre-mixed material of 15 mmol polysiloxane A and 1.1 eq triethylamine in toluene under dry atmosphere and ice cooling (4 C.) a solution of 1.1 eq. tert-butylbenzoyl chloride in toluene was slowly added in drops. Once addition was complete the solution was agitated at room temperature. The conversion was monitored via the reduction in the band characteristic of the OH group by IR spectroscopy; the band characteristic of the OH group was detected under IR at 3200-3400 cm.sup.1. For working up the solution was initially extracted with 1M HCl and then washed twice with water. Following drying of the organic phase over magnesium sulphate and removal of the solvent under vacuum a slightly yellowy flowable resin with a viscosity of 13.5 Pa.Math.s at 25 C. was obtained. Table 2 provides a comparison of physical properties.

(12) 2.3) Preparation of a Polysiloxane Compound According to the Invention (Polysiloxane D) by Conversion of Polysiloxane a with n-Dodecanoyl Chloride:

(13) To a pre-mixed material of 15 mmol polysiloxane A and 1.1 eq. triethylamine in toluene under dry atmosphere and ice cooling (4 C.) a solution of 1.1 eq. n-dodecanoyl chloride in toluene was slowly added in drops. Once addition was complete the solution was agitated at room temperature. The conversion was monitored via the reduction in the band characteristic of the OH group by IR spectroscopy; the band characteristic of the OH group was detected under IR at 3200-3400 cm.sup.1. For working up the solution was initially extracted with 1M HCl and then washed twice with water. Following drying of the organic phase over magnesium sulphate and removal of the solvent under vacuum a slightly yellowy flowable resin with a viscosity of 1.5 Pa.Math.s at 25 C. was obtained. Table 2 provides a comparison of physical properties.

(14) 2.4) Preparation of a Polysiloxane Compound (Amide) According to the Invention (Polysiloxane E) by Conversion of Polysiloxane a with (i) Para-Toluenesulfonyl Chloride and Subsequently with (ii) Naphthalene-1-Carboxamide (See Diagram (m)):

(15) A solution of 16.5 mmol (1.1 eq.) para-toluenesulfonyl chloride in 50 ml of a mixture of acetone/toluene (volume ratio: 1:1) was mixed under ice cooling (4 C.) with 16.5 mmol triethylamine (1.1 eq.). The resulting mixture was subsequently mixed with 15 mmol polysiloxane A (1.0 eq.). Once mixing was complete the resulting clear solution was continually agitated at 4 C. for one hour. Afterwards, a solution of 1.1 eq. naphthalene-1-carboxamide and 1.1 eq. triethylamine in 5 ml acetone/toluene (volume ratio: 1:1) was slowly added in drops. The resulting solution was heated to 75 C. and said temperature was maintained for 3 hours.

(16) In a next step the solution was washed with water three times and the organic phase was dried over magnesium sulphate. Following removal of the solvent under vacuum a slightly yellowy flowable (liquid) resin with a viscosity of 24 Pa.Math.s at 25 C., a refractive index n.sub.D of 1.52, and a shrinkage of 3.6% was obtained. Table 2 provides a comparison of physical properties.

(17) ##STR00038##

(18) 2.5) Preparation of a Polysiloxane Compound (Thioester) According to the Invention (Polysiloxane F) by Conversion of Polysiloxane a with (i) Para-Toluenesulfonyl Chloride and Subsequently with (ii) Naphthalene-1-Thiocarboxylic Acid (See Diagram (n)):

(19) A solution of 16.5 mmol (1.1 eq.) para-toluenesulfonyl chloride in 50 ml of a mixture of acetone/toluene (volume ratio: 1:1) was mixed under ice cooling (4 C.) with 16.5 mmol triethylamine (1.1 eq.). The resulting mixture was subsequently mixed with 15 mmol polysiloxane A (1.0 eq.). Once mixing was complete the resulting clear solution was continually agitated at 4 C. for one hour. Afterwards, a solution of 1.1 eq. naphthalene-1-thiocarboxylic acid and 1.1 eq. triethylamine in 5 ml acetone/toluene (volume ratio: 1:1) was slowly added in drops. The resulting solution was heated to 75 C. and said temperature was maintained for 3 hours.

(20) In a next step the solution was washed with water three times and the organic phase was dried over magnesium sulphate. Following removal of the solvent under vacuum a slightly yellowy flowable (liquid) resin with a viscosity of 15 Pa.Math.s at 25 C., a refractive index no of 1.53, and a shrinkage of 3.6% was obtained. Table 2 provides a comparison of physical properties.

(21) ##STR00039##

(22) TABLE-US-00002 TABLE 2 Physical properties of polysiloxane compounds according to the invention (B, C, D, E, and F) compared with the polysiloxane A not according to the invention. *The flexural strength and shrinkageproperties were determined in the cured state (see Points C-3 and C-4 below). Polysiloxane A (reference) Polysiloxane B Polysiloxane C Polysiloxane D Polysiloxane E Polysiloxane F Flexural 32 43 39 35 44 42 strength* Shrinkage* 4.8 3.6 3.4 3.7 3.6 3.6 Viscosity 4.5 17.5 13.5 1.5 24 15 Refractive 1.47 1.52 1.49 1.48 1.52 1.53 index n.sub.D

(23) The viscosity of polysiloxanes according to the invention (polysiloxanes B, C, D, E, and F) is not disadvantageously changed compared with the viscosity of polysiloxanes not according to the invention (polysiloxane A) (in any event in the case of polysiloxanes B, C, E, and F the increase is insignificant).

(24) Polysiloxane compounds according to the invention have a refractive index in the preferred area of 1.48 to 1.54 and thus a higher refractive index than the refractive index of 1.47 of the polysiloxane A not in accordance with the invention.

B) PREPARATION AND PROPERTIES OF CURABLE DENTAL MATERIALS (COMPOSITES A TO E)

(25) In a 100 ml laboratory kneader the respective polysiloxane compounds (polysiloxane A, B, C, D, E, and F) and additional compounds/substances according to Table 3 were mixed together in the proportions indicated there, resulting in homogenous, paste-like formulations (precursors to a composite A not according to the invention and precursors to composites B to G according to the invention). Following de-aeration of the paste-like formulations under vacuum (at a pressure of 0.9 bar) the de-aerated, paste-like formulations (composites A to G) were characterised according to their flexural strength and their polymerisation shrinkages (shrinkage). A comparison of the results is shown in Table 4.

(26) All details in Table 3 are given in weight percent, in relation to the total weight of the respective composite.

(27) TABLE-US-00003 TABLE 3 Compositions of curable dental materials having as a basis polysiloxane compounds according to the invention (polysiloxanes B, C, D, E, and F (used in composites B to G)) or as a basis the polysiloxane A not according to the invention (used in composite A). All curable dental materials (composites) contain as initiators/inhibitors the same quantities of camphor quinone (0.4 wt. %) and dimethyl pare amino benzoic acid (0.6 wt. %) for initiation and the same quantities of butylhydroxytoluene (0.1 wt. %) for inhibition. Composite A Components (reference) Composite B Composite C Composite D Composite E Composite F Composite G Polysiloxane A 20 0 0 0 0 0 0 Polysiloxane B 0 20 0 0 10 0 0 Polysiloxane C 0 0 20 0 0 0 0 Polysiloxane D 0 0 0 20 0 0 0 Polysiloxane E 0 0 0 0 0 20 0 Polysiloxane F 0 0 0 0 0 0 20 BisGMA/TEGDMA 0 0 0 0 10 0 0 in a mass ratio of 1:1 Barium 15.8 15.8 15.8 15.8 15.8 15.8 15.8 silicate glass (0.7 m) silanised Barium 63.1 63.1 63.1 63.1 63.1 63.1 63.1 silicate glass (1.5 m) silanised Initiators/ 1.1 1.1 1.1 1.1 1.1 1.1 1.1 inhibitors

(28) TABLE-US-00004 TABLE 4 Physical properties and associated values of composites A, B, C, D, E, F, and G. The flexural strength and shrinkage properties were determined in the cured state (see Points C-3 and C-4 below). Composite A Composite B Composite C Composite D Composite E Composite F Composite G Flexural 110 125 127 120 155 126 128 strength Shrinkage 1.5 1.2 1.1 1.3 1.9 1.2 1.2

(29) The curable dental materials according to the invention (composites B to G) in the cured state have a higher flexural strength than the flexural strength of a curable dental material not according to the invention (composite A) comprising a polysiloxane A not according to the invention (as described above).

(30) Curable dental materials according to the invention (composites B to D, and F and G) are also characterised in that they experience less shrinkage upon curing than a curable dental material not according to the invention (composite A) comprising a polysiloxane A not according to the invention (as described above).

C) METHODS OF DETERMINATION FOR DETERMINING THE PHYSICAL PROPERTIES OF THE POLYSILOXANE COMPOUNDS OR THE CURABLE DENTAL MATERIALS (COMPOSITES)

(31) C-1) Determination of the Viscosity:

(32) The viscosity was determined using a rheometer (Physica MCR 301) from Anton Paar. To do so in each case 4 g of the non-polymerised polysiloxane (polysiloxane A, B, C, D, E, or F) was evenly spread over a 50 mm rheometer plate. Then the material was sheared at 25 C. by means of a rotational movement (the shearing speed (shear rate) y was selected such that it covered a range of 0.5 to 10 s.sup.1). The viscosity of the material was determined at 20 measurement points which were in each case recorded at a 10 s interval. The last measurement point indicates the viscosity at maximum shear. The viscosity is shown in Table 2 above in Pa.Math.s.

(33) C-2) Determination of the Refractive Index:

(34) The refractive index was determined by means of a refractometer (RE40) from Mettler Toledo in each case from 1 g of the non-polymerised polysiloxane (polysiloxane A, B, C, D, E, or F). The refractive index is a dimensionless physical variable.

(35) C-3) Determination of the Flexural Strength:

(36) The flexural strength of the polysiloxanes (polysiloxane A, B, C, D, E, or F, see Table 2, flexural strength) or the curable dental materials (composites A to G, see Table 4, flexural strength) was determined in accordance with FprEN ISO 4049 in each case from 5 correspondingly cured materials (test specimens) (see FprEN ISO 4049, points 7.11.3 and 7.11.4). The flexural strength is shown in the above Tables 2 and 4 in Megapascal (MPa).

(37) For the investigations on the respective polysiloxanes A to F these were activated for curing by addition of in each case 3 g/kg camphor quinone and 4.5 g/kg dimethyl para amino benzoic acid. The activated polysiloxanes thus obtained were then in each case transferred into a Teflon mould (2 mm*2 mm*50 mm) and the top of the Teflon mould covered with an ethyl acetate film. The specimens obtained in this way were then exposed to light with a wavelength ranging from 400 to 500 nm in a light box for a period of 60 minutes, providing cured test specimens. These cured test specimens were then released from the Teflon mould and stored for 24 hours in a water bath with a water temperature of 37 C. The flexural strength was then measured using a force measuring device from Zwick Roell Z005 KAS-TC (year of construction 2007) at a force progression of 5016 N/min.

(38) The investigations on the respective composites (composites A to G, see the respective compositions according to Table 3) were performed under the same conditions and with the same methods (but without further addition of initiators such as camphor quinone and dimethyl para amino benzoic acid), as indicated above for the investigations on the polysiloxanes.

(39) C-4) Determination of the Polymerisation Shrinkages:

(40) The polymerisation shrinkages of the polysiloxanes (polysiloxane A, B, C, D, E, or F see Table 2, Shrinkage) or of the curable dental material (see Table 4, Shrinkage) were measured using the Watts* method on correspondingly cured dental materials. The polymerisation shrinkage (Shrinkage) is shown in the above Tables 2 and 4 in percent by volume (vol. %), in relation to the volume of the test specimen prior to curing. The values shown in Tables 2 and 4 signify a volume reduction in percent following curing.

(41) For the investigations on the respective polysiloxanes these were activated for curing with 3 g/kg camphor quinone and 4.5 g/kg dimethyl para amino benzoic acid. The shrinkage was investigated in the context of a photo-induced radical polymerisation with light of a wavelength ranging from 400 to 500 nm according to the Watts method.

(42) The investigations on the respective composites (composites A to G, see the respective compositions according to Table 3) were performed similarly to the investigations on the polysiloxanes, but without further addition of initiators such as camphor quinone and dimethyl pare amino benzoic acid.

(43) *Method according to Watts D. C., Cash A. J.: Determination of polymerization shrinkage kinetics in visible light cured materials: methods development, Dental Materials 1991; 7; 281