Title of Invention	A MODIFIED CERAMIC RESIN FOR USE IN DENTAL APPLICATIONS AND A PROCESS FOR THE PREPARATION THEREOF
Abstract	A process for the preparation of a modified ceramic resin for use in dental applications, comprising the steps of preparing a precursor followed by hydrolysis of the precursor to yield the hydrolysed precursor subjecting the hydrolysed precursor to a step of post- condensation to obtain the organic matrix, providing an inorganic matrix comprising an inorganic compound, such as a metal alkoxlde of general formula MBOb (OR)selected from the group Si, AI, Ca and Ti and (OR) is the methacrylate group a=4-6 c=4-8 mixing the inorganic and organic matrix at the molecular level in a solvent and in the presence of a base catalyst to obtain a resin followed by drying and Inhibiting the same to obtain the modtned ceramic resin

Title of Invention

A MODIFIED CERAMIC RESIN FOR USE IN DENTAL APPLICATIONS AND A PROCESS FOR THE PREPARATION THEREOF

Abstract

A process for the preparation of a modified ceramic resin for use in dental applications, comprising the steps of preparing a precursor followed by hydrolysis of the precursor to yield the hydrolysed precursor subjecting the hydrolysed precursor to a step of post- condensation to obtain the organic matrix, providing an inorganic matrix comprising an inorganic compound, such as a metal alkoxlde of general formula MBOb (OR)selected from the group Si, AI, Ca and Ti and (OR) is the methacrylate group a=4-6 c=4-8 mixing the inorganic and organic matrix at the molecular level in a solvent and in the presence of a base catalyst to obtain a resin followed by drying and Inhibiting the same to obtain the modtned ceramic resin

Full Text	FIELD OF THE INVENTION This invention relates to a modified ceramic resin for use in dental and related applications, and a process for the preparation thereof BACKGROUND OF THE INVENTION Tailoring of malfunctional organically modified ceramics precursors in the basis for their use as matrices for dental composites including various fillers. Low shrinkage during curing, good mechanical abrasion resistance, suitable elasticity, adhesion to the teeth and good toxicological data led to the successful development of organicaJly modified ceramics as matrix components or matrix with an adapted bonding for dental composite applications. Inorganic-organic polymers are basically known from the prior art and are designated as 'ormocer' or ormosir. The sol-gel process m the presence of acidic or basic catalysts prepares these polymers. OBJECTS OF THE INVENTION It is an object of this invention to propose a modified ceramic resin for use in dental and related applications which is easy to prepare and is cost-effective. It is a further object of this invention to propose a modified ceramic resin for use in dental and related applications which is a single paste system. These and other objects of the invention will be more apparent from the ensuing description. At the outset of the description which follows, it is to be understood that the ensuing description only illustrates a particular fonn of this embodiment. However, such a particular form is only an exemplary embodiment and the teachings of the invention is not intended to be taken restrictively. BRIEF DESCRIPTION OF THE INVENTION According to this invention is provided a modified ceramic resin for use in dental and related applications. According to this invention is further provided a process for the preparation of a modified ceramic res'm for use in dental and related applications, comprising the steps of preparing a precursor followed by hydrolysis of tlie precursor to yield the hydrolysed precursor, subjecting the hydrolysed precursor to a step of post-condensation to obtain the oligomer, mixing an inorganic and organic matrix at the molecular level in a solvent and in the presence of a base catalyst to obtain a resin followed by drying and inhibiting the same to obtain the modified ceramic resin. hi accordance with this invention, and by v/ay of an exemplary embodiment, 0.75-L5 moles of a compound, such as for eg, 1,3-bis (methacryloxy)2-hydroxy propane (MHP) is reacted with (0.7-1.55 mobs) of a compound, such as for eg. chloropropyl trimethoxy siiane in the presence of a basic catalyst at 45-5 5^C for 3-5 hrs. in an inert atmosphere to obtain the precursor. The catalyst is for eg. benzyl triethyl ainmoiiium chloride aiid the inert atmosphere comprises aii atmosphere of nitrogen. The inhibitor usod is such as for eg. 4-methoxy phenol It was characterised using infrared spectroscopy. The second step involved is of 0.8-1.5 moles of the said precursor v^ith 2.4-4.5 moles of distilled water in the presence of a catalyst at a temperature 25-3S^'C for a duration of 6-10 hrs. under constant stirring. ' The third step involved post-condensation of the hydrolyzed precursor for a duration of 10-14 hrs. at 25-35'^C followed by washing with distilled water. The fourth step involved mixing of organic (90-99.1 parts) and inorganic (0.9-10 parts) matrix at the molecular level by dissolvmg in an organic solvent such as diethyl ether (30-40% solution in ether) in presence of abase catalyst (0.1-5% by weight of reactants) at 25-35''C for duration of 3-5 hrs. The resultant resin is dried at 30-40^^0 for 100-144 hrs. and inhibited with 150-300 ppm inhibitor and stored at 22±2^C. The catalyst used is preferably a base catalyst such as 0.2 to 10% by weight of the reactants, of benzyltriethylammonium chloride or 0.5 to 2N sodium hydroxide. The refractive index of the resin was measured using an ABBE refractonieter (Model 3T, Atago, Japan). The infrared spectrum w^ recorded using an FTIR infrared spectrophotometer (Nicelet Impact 4000 USA). High-pressure liquid chromatographic analysis was carried out using ethanoJ sohition. Methanol was usod as the mohlk phase (Flow rate Iml/m'm, 4S6 tiinabh UV-detector, 210 nm, Waters Associates Model 440). The inorgtuiic compound is such as for eg. an alkoxide having (he general formula MaOt,(OR)c where M k selected from the group Si, Al, CB. and Ti and (OR) is the methacrylate group, a-4-6 b > I and c = 4-8 In accordance with an embodiment of this invention, there is a second step of formation of an additional network after the build-up of the inorganic network. The resin obtained from the reaction is stort^d at 22-24"C. In accordance with a further embodiment of this invention, the product is used for the preparation of a novel dctiVd fiUmg m aterial by using a thinner and filhr. The thinner is selected from compounds such as triethylene glycol dim eth aery late (TEGDMA), ethylene glycol dim eth aery late (EDMA) and other similar monomers and the filler is for eg. silanated quartz. The dental filling material is prepared using 20-40 parts of resin mixture with 60-80 parts of filler. The particle size of the filler is less than 5 microns. The filler is treated with 0.5-1.5% by weight of a silane-coupling agent before being mixed with the thinned oligomer. The dental filling composition further comprises additives such as photo initiator, inhibitor and accelerator. The inhibitor (H) also includes UV stabilisers. The photoinitiator is present in 0.1-1% by weight of resin mixture and the accelerator is used in 10-1000 ppm based on the weight of resin mixture. The accelerator is a tertiary amine such as 2-(4"dimethyl aminophenyethyl) ethanol (DMAPEA) or dimethyl paratouiidine (DMPT). Mixing is carried out at room temperature. The paste cutf^s into a hard solid when exposed to a visible light of 440-480 nm wavelength for a period of 20-60 sees. and the cured paste provides a CS 250-300 MPa, DTS 40-40 MPa, FS 70-120 MPa, FM 740 GPa, VMH 80-100 kg/mm^ WS and S The invention will now be explained in greater details with the help of the following nouAlmititig examples. Example 1 In whose process the following steps are involved. The first ste^p involved preparation of a precursor by roaicting (0.75 -1.5 moles) of 1,3 bis (methacryloxy) 2-hydroxy propane (MHP) (with (0.7 - 1.55 moles) of a compound such as for e.g. chloropropyl triinethoxy silaiie in presence of a basic catalyst at 45-55 "C for 3-5 hours in an inert atmosphere, to obtain the precursor. It was characterised using infrared spectroscopy. The- second step involved hydrolysis of 0.8 to 1.5 moles of the.said precursor with 2.4 to 4.5 moles of distilled water in presence of a catalyst at a temperature 25-35 "C for a duration of 6-10 hours under constant stirring. The third step involved postcondensation of the hydrolyzed precursor for a duration of 10-14 hours at 25-35 ^C followed bv washing with distilled water. The fourth step involved mixing of organic (90-99.1 parts) and inorganic (0.9-10 parts) matrix at the- molecular level by dissolving in an organic solvent such as diethyl ether (30-40%) solution in ether) in presence of a base cat-alyst (0.1 -5% by weight of CH3+ IC =CHO OH OCH 1 1 1 H2C-C-CH3 reactants) at 26-35 C for duration of 3-5 hours. The resultant resin is dried at 30-40 °C for 100 - 144 hours and Inhibited with 150-300 ppm inhibitor and stores at 22 + 2 '^C. The refractive index of the resin was measured using an ABBE refractometer (Model 3T, Atago, Japan). The infrared spectrum was recorded using an FTIR infrared spectrophotometer (Nicolet Impact 4000 USA). High-pressure liquid chromatographic analysis was canied out using ethanol solution. Methanol was used as the mobile phase -(Flow rate Iml/min., 486 tunable UV - detector, 210 nm. Waters Associates Model 440). Example 2 The first step involved hydrolysis of 3 (trimethoxy) silyl propyl methacrylate (0.8-1.5 moles) with distilled water (2.4-4.5 moles) in presence of a catalyst at a temperature 25-3 5^0 for a duration of 6-10 hours under constant stirring. The second step involved post condensation of the hydrolyzed precursor for a duration of 10-14 hours at 25-35T . The third step involved mixing of organic (90-99.1 parts) and inorganic (0.9-10 paits7'matrix at the molecular level by dissolving in an organic solvent such as diethyl ether (30-40% solution in ether) in presence of a base catalyst (0.1-0.5% by weight of reactants) at 25-35^C for duration of 3-5 hours. The resultant resin is dried at 30-40"C for 100-144 hours and inhibited with 150- 300 ppm inliibitor and stored at 22±2T. The refractive index of the resin was measured using an ABBE refractometer (Model 3T, Atago, Japan). The infrared spectrum was recorded using a FTIR infrared spectrophotometer (Nicolet Impact 4000 USA). High-pressure liquid chromatographic analysis was carried out using ethanol solution. Methanol was used as the mobile phase (Flow rate Iml/min., 486 tunable UV - detector, 210 nm. Waters Associates Model 440). WE CLAIM: 1. Theprocessfor the preparation of a modified ceramic resin for use in dental and related applications, comprising the steps of preparing a precursor followed by hydrolysis of tlie precursor to yield tlie hydrolysed precursor, subjecting the hydrolysed precursor to a step of post-condensation to obtain the oligomer, mixing an inorganic and organic matrix at the molecular level in a solvent and in the presence of abas\|; catalyst to obtain a resin followed by drying and inhibiting the same to obtain the modified ceramic resin. 2. The process as claimed in claim 1, wherein 0.75 to 1.5 moles of a compound such as 1,3 bis methacryloxy) 2 hydroxy propane (MHP) is a reacted with 0.7 to 1.4 moles of a siiane compound such as 3 chloropropyi trimethoxy siiane for 3 to 5 hours to obtain the precursor. 3. The process as claimed in claim 2, wherein a catalyst is used in 0.75 to 1.55 parts by weight of the reactants. 4. The process as claimed in claim 2, wherein the precursor is prepared at a temperature in the range of 45 to 55 0C, in an inert atmosphere. 5. The process as claimed in claim 1, wherein said hydrolysis is an acid catalysed hydrolysis at a temperature in the range of 25 to 35 ^C for atime period of 6 to 10 hours. 6. The process as claimed in claim 5, wherein said acid catalysed hydrolysis is carried out in the presence of a 5 to 10% solution of hydrochloric acid. 1. The process as claimed in claim 1, wherein the step of post-condensation is carried out over a period of 10 to 14 hours at 25 to35^C. 8. The process as claimed in claim 1, wherem the step of mixing of organic and inorganic matrix at the molecular level is continued for 3-5 hours at 25-35 ""C in presence of abase catalyst. 9. The process as claimed in claim 1, 8, wherein 90 to 99.1 parts by weight of organic matrix is mixed with 0.9 to 10 parts by weight of inorganic matrix, 10. The process as claimed in claim 1, wherein the m ixing is carried in a solvent which is 2-4 times the weight of the reactants. 11. The process as claimed in claim 1, wherein the catalyst used in the step of mixing is selected from 0.2 to 1% benzyl triethuyl ammonium chloride or 0.5 to 2N sodium hydroxide. 12. The process as claimed in claim 1, wherein said resin is dried at 30 to 40 T for 24 to 144 hours. 13. A modified ceramic resin for use in dental and related applications. 14. A u-jLvel dental fillhig material comprising said 20 - 40 parts resin and 60 - 80 parts of a filler alongwith a thinner and optionally, additives such as photohiitiator, inhibitor, uv stabiliser, accelerator etc. 15. The novel dental filling material as claimed in cL^im 14, wherein said thinner is triethylene glycol dimethaery late (TEGDMA), ethylene glycol dimethacrylate (EDMA) and other similar monomers. 16. The filling material as claimed in claim 14, wherein said filled is silanated quartz. 17. The process as claimed in claim 14, wherein said filler has a particle size of less than 5 U, 18. The process as claimed in claim 14, wherein said filler is treated with 0.5 to 1.5% by weight of asilane couplrag agent before being mixed with the thinned resin. 19. The process as claimed in claim 14, wherein said photo initator is a diketone and is used in amounts of 0.1-1% by weight of resin mixture. 20. The process as claimed in claim 14, wherein said inhibitor is used in 10-1000 ppm based on the weight of the resin mixture. 21. The process as claimed in claim 14, wherein the inhibitor also includes uv stabilisers selected from phenyl salieylate optionally in combination with 2-hydroxy - 4-methoxybenzophenone. 22. The process as claimed in claim 14, wherein the inhibitor is 2, 6 - detertiarybutal 4-methyl phenol. 23. The process as claimed in claim 14, wherein said accelerator is present in 0.1 to 1% by weight of the thinned resin. 24. The process as claimed in claim 14, wherein said acclerator is a tertiary amine such as 2-(4-dimethyl aminophenyethyl) ethanol (DMAPEA) or dimethyl paratoulidine (DMPT). 25. The process as claimed in calim 14, wherein cures in to a hard solid when exposed to a visible light of 440-480 nm wavelength for a period of 20-60 seconds. 26. The process as claimed in claim 14, having aCS 250-300 Mpa, DTS 40-50 Mpa, FS 70-120 Mpa, FM 7-lOGpa, VMH 80-100 Kg/mm 2 WS

Full Text

FIELD OF THE INVENTION
This invention relates to a modified ceramic resin for use in dental and related applications, and a process for the preparation thereof
BACKGROUND OF THE INVENTION
Tailoring of malfunctional organically modified ceramics precursors in the basis for their use as matrices for dental composites including various fillers. Low shrinkage during curing, good mechanical abrasion resistance, suitable elasticity, adhesion to the teeth and good toxicological data led to the successful development of organicaJly modified ceramics as matrix components or matrix with an adapted bonding for dental composite applications. Inorganic-organic polymers are basically known from the prior art and are designated as 'ormocer' or *ormosir. The sol-gel process m the presence of acidic or basic catalysts prepares these polymers.
OBJECTS OF THE INVENTION
It is an object of this invention to propose a modified ceramic resin for
use in dental and related applications which is easy to prepare and is
cost-effective.
It is a further object of this invention to propose a modified ceramic
resin for use in dental and related applications which is a single paste
system.
These and other objects of the invention will be more apparent from the ensuing description.

At the outset of the description which follows, it is to be understood that the ensuing description only illustrates a particular fonn of this embodiment. However, such a particular form is only an exemplary embodiment and the teachings of the invention is not intended to be taken restrictively.
BRIEF DESCRIPTION OF THE INVENTION
According to this invention is provided a modified ceramic resin for use in dental and related applications. According to this invention is further provided a process for the preparation of a modified ceramic res'm for use in dental and related applications, comprising the steps of preparing a precursor followed by hydrolysis of tlie precursor to yield the hydrolysed precursor,
subjecting the hydrolysed precursor to a step of post-condensation to obtain the oligomer,
mixing an inorganic and organic matrix at the molecular level in a solvent and in the presence of a base catalyst to obtain a resin followed by drying and inhibiting the same to obtain the modified ceramic resin.
hi accordance with this invention, and by v/ay of an exemplary embodiment, 0.75-L5 moles of a compound, such as for eg, 1,3-bis (methacryloxy)2-hydroxy propane (MHP) is reacted with (0.7-1.55 mobs) of a compound, such as for eg. chloropropyl trimethoxy siiane in the presence of a basic catalyst at 45-5 5^C for 3-5 hrs. in an inert

atmosphere to obtain the precursor. The catalyst is for eg. benzyl triethyl ainmoiiium chloride aiid the inert atmosphere comprises aii atmosphere of nitrogen. The inhibitor usod is such as for eg. 4-methoxy phenol It was characterised using infrared spectroscopy.
The second step involved is of 0.8-1.5 moles of the said precursor v^ith 2.4-4.5 moles of distilled water in the presence of a catalyst at a temperature 25-3S^'C for a duration of 6-10 hrs. under constant stirring.
**' The third step involved post-condensation of the hydrolyzed precursor
for a duration of 10-14 hrs. at 25-35'^C followed by washing with
distilled water.
The fourth step involved mixing of organic (90-99.1 parts) and inorganic (0.9-10 parts) matrix at the molecular level by dissolvmg in an organic solvent such as diethyl ether (30-40% solution in ether) in presence of abase catalyst (0.1-5% by weight of reactants) at 25-35''C for duration of 3-5 hrs. The resultant resin is dried at 30-40^^0 for 100-144 hrs. and inhibited with 150-300 ppm inhibitor and stored at 22±2^C.
The catalyst used is preferably a base catalyst such as 0.2 to 10% by weight of the reactants, of benzyltriethylammonium chloride or 0.5 to 2N sodium hydroxide. The refractive index of the resin was measured

using an ABBE refractonieter (Model 3T, Atago, Japan). The infrared spectrum w^ recorded using an FTIR infrared spectrophotometer (Nicelet Impact 4000 USA). High-pressure liquid chromatographic analysis was carried out using ethanoJ sohition. Methanol was usod as the mohlk phase (Flow rate Iml/m'm, 4S6 tiinabh UV-detector, 210 nm, Waters Associates Model 440).
The inorgtuiic compound is such as for eg. an alkoxide having (he general formula MaOt,(OR)c where M k selected from the group Si, Al, CB. and Ti and (OR) is the methacrylate group, a-4-6 b > I and c = 4-8
In accordance with an embodiment of this invention, there is a second step of formation of an additional network after the build-up of the inorganic network. The resin obtained from the reaction is stort^d at 22-24"C.
In accordance with a further embodiment of this invention, the product is used for the preparation of a novel dctiVd fiUmg m aterial by using a thinner and filhr. The thinner is selected from compounds such as triethylene glycol dim eth aery late (TEGDMA), ethylene glycol dim eth aery late (EDMA) and other similar monomers and the filler is for eg. silanated quartz. The dental filling material is prepared using

20-40 parts of resin mixture with 60-80 parts of filler. The particle size of the filler is less than 5 microns. The filler is treated with 0.5-1.5% by weight of a silane-coupling agent before being mixed with the thinned oligomer. The dental filling composition further comprises additives such as photo initiator, inhibitor and accelerator. The inhibitor (H) also includes UV stabilisers. The photoinitiator is present in 0.1-1% by weight of resin mixture and the accelerator is used in 10-1000 ppm based on the weight of resin mixture. The accelerator is a tertiary amine such as 2-(4"dimethyl aminophenyethyl) ethanol (DMAPEA) or dimethyl paratouiidine (DMPT). Mixing is carried out at room temperature. The paste cutf^s into a hard solid when exposed to a visible light of 440-480 nm wavelength for a period of 20-60 sees. and the cured paste provides a CS 250-300 MPa, DTS 40-40 MPa, FS 70-120 MPa, FM 740 GPa, VMH 80-100 kg/mm^ WS and S The invention will now be explained in greater details with the help of the following nouAlmititig examples.
Example 1
In whose process the following steps are involved.
The first ste^p involved preparation of a precursor by roaicting (0.75 -1.5 moles) of 1,3 bis (methacryloxy) 2-hydroxy propane (MHP) (with

(0.7 - 1.55 moles) of a compound such as for e.g. chloropropyl triinethoxy silaiie in presence of a basic catalyst at 45-55 "C for 3-5 hours in an inert atmosphere, to obtain the precursor. It was characterised using infrared spectroscopy.
The- second step involved hydrolysis of 0.8 to 1.5 moles of the.said precursor with 2.4 to 4.5 moles of distilled water in presence of a catalyst at a temperature 25-35 "C for a duration of 6-10 hours under constant stirring.
The third step involved postcondensation of the hydrolyzed precursor for a duration of 10-14 hours at 25-35 ^C followed bv washing with distilled water.
The fourth step involved mixing of organic (90-99.1 parts) and
inorganic (0.9-10 parts) matrix at the- molecular level by dissolving in
an organic solvent such as diethyl ether (30-40%) solution in
ether) in presence of a base cat-alyst (0.1 -5% by weight of
CH3+ IC =CHO OH OCH
1 1 1 H2C-C-CH3
reactants) at 26-35 C for duration of 3-5 hours. The resultant resin is dried at 30-40 °C for 100 - 144 hours and Inhibited with 150-300 ppm inhibitor and stores at 22 + 2 '^C.

The refractive index of the resin was measured using an ABBE refractometer (Model 3T, Atago, Japan). The infrared spectrum was recorded using an FTIR infrared spectrophotometer (Nicolet Impact 4000 USA). High-pressure liquid chromatographic analysis was canied out using ethanol solution. Methanol was used as the mobile phase -(Flow rate Iml/min., 486 tunable UV - detector, 210 nm. Waters Associates Model 440).
Example 2
The first step involved hydrolysis of 3 (trimethoxy) silyl propyl methacrylate (0.8-1.5 moles) with distilled water (2.4-4.5 moles) in presence of a catalyst at a temperature 25-3 5*^0 for a duration of 6-10 hours under constant stirring.
The second step involved post condensation of the hydrolyzed precursor for a duration of 10-14 hours at 25-35T .
The third step involved mixing of organic (90-99.1 parts) and inorganic (0.9-10 paits7'matrix at the molecular level by dissolving in an organic solvent such as diethyl ether (30-40% solution in ether) in presence of a base catalyst (0.1-0.5% by weight of reactants) at 25-35*^C for duration of 3-5 hours. The resultant resin is dried at 30-40"C for 100-144 hours and inhibited with 150- 300 ppm inliibitor and stored at 22±2T.
The refractive index of the resin was measured using an ABBE refractometer (Model 3T, Atago, Japan). The infrared spectrum was recorded using a FTIR infrared spectrophotometer (Nicolet Impact 4000 USA). High-pressure liquid chromatographic analysis was carried out using ethanol solution. Methanol was used as the mobile phase (Flow rate Iml/min., 486 tunable UV - detector, 210 nm. Waters Associates Model 440).

WE CLAIM:
1. Theprocessfor the preparation of a modified ceramic resin for
use in dental and related applications, comprising the steps of
preparing a precursor followed by hydrolysis of tlie precursor to
yield tlie hydrolysed precursor,
subjecting the hydrolysed precursor to a step of post-condensation to obtain the oligomer,
mixing an inorganic and organic matrix at the molecular level in a solvent and in the presence of abas|; catalyst to obtain a resin followed by drying and inhibiting the same to obtain the modified ceramic resin.
2. The process as claimed in claim 1, wherein 0.75 to 1.5 moles of a compound such as 1,3 bis *methacryloxy) 2 hydroxy propane (MHP) is a reacted with 0.7 to 1.4 moles of a siiane compound such as 3 chloropropyi trimethoxy siiane for 3 to 5 hours to obtain the precursor.
3. The process as claimed in claim 2, wherein a catalyst is used in 0.75 to 1.55 parts by weight of the reactants.
4. The process as claimed in claim 2, wherein the precursor is prepared at a temperature in the range of 45 to 55 0C, in an inert atmosphere.

5. The process as claimed in claim 1, wherein said hydrolysis is an acid catalysed hydrolysis at a temperature in the range of 25 to 35 ^C for atime period of 6 to 10 hours.
6. The process as claimed in claim 5, wherein said acid catalysed hydrolysis is carried out in the presence of a 5 to 10% solution of hydrochloric acid.
1. The process as claimed in claim 1, wherein the step of post-condensation is carried out over a period of 10 to 14 hours at 25 to35^C.
8. The process as claimed in claim 1, wherem the step of mixing of organic and inorganic matrix at the molecular level is continued for 3-5 hours at 25-35 ""C in presence of abase catalyst.
9. The process as claimed in claim 1, 8, wherein 90 to 99.1 parts by weight of organic matrix is mixed with 0.9 to 10 parts by weight of inorganic matrix,
10. The process as claimed in claim 1, wherein the m ixing is carried in a solvent which is 2-4 times the weight of the reactants.

11. The process as claimed in claim 1, wherein the catalyst used in the step of mixing is selected from 0.2 to 1% benzyl triethuyl ammonium chloride or 0.5 to 2N sodium hydroxide.
12. The process as claimed in claim 1, wherein said resin is dried at 30 to 40 T for 24 to 144 hours.
13. A modified ceramic resin for use in dental and related applications.
14. A u-jLvel dental fillhig material comprising said 20 - 40 parts resin and 60 - 80 parts of a filler alongwith a thinner and optionally, additives such as photohiitiator, inhibitor, uv stabiliser, accelerator etc.
15. The novel dental filling material as claimed in cL^im 14, wherein said thinner is triethylene glycol dimethaery late (TEGDMA), ethylene glycol dimethacrylate (EDMA) and other similar monomers.
16. The filling material as claimed in claim 14, wherein said filled is silanated quartz.
17. The process as claimed in claim 14, wherein said filler has a particle size of less than 5 U,

18. The process as claimed in claim 14, wherein said filler is treated with 0.5 to 1.5% by weight of asilane couplrag agent before being mixed with the thinned resin.
19. The process as claimed in claim 14, wherein said photo initator is a diketone and is used in amounts of 0.1-1% by weight of resin mixture.
20. The process as claimed in claim 14, wherein said inhibitor is used in 10-1000 ppm based on the weight of the resin mixture.
21. The process as claimed in claim 14, wherein the inhibitor also includes uv stabilisers selected from phenyl salieylate optionally in combination with 2-hydroxy - 4-methoxybenzophenone.
22. The process as claimed in claim 14, wherein the inhibitor is 2, 6 - detertiarybutal 4-methyl phenol.
23. The process as claimed in claim 14, wherein said accelerator is present in 0.1 to 1% by weight of the thinned resin.
24. The process as claimed in claim 14, wherein said acclerator is a tertiary amine such as 2-(4-dimethyl aminophenyethyl) ethanol (DMAPEA) or dimethyl paratoulidine (DMPT).

25. The process as claimed in calim 14, wherein cures in to a hard
solid when exposed to a visible light of 440-480 nm wavelength
for a period of 20-60 seconds.
26. The process as claimed in claim 14, having aCS 250-300 Mpa,
DTS 40-50 Mpa, FS 70-120 Mpa, FM 7-lOGpa, VMH 80-100
Kg/mm 2 WS

Documents:

483-che-2003 description (complete) granted.pdf

483-che-2003-claims.pdf

483-che-2003-correspondnece-others.pdf

483-che-2003-correspondnece-po.pdf

483-che-2003-description(complete).pdf

483-che-2003-description(provisional).pdf

483-che-2003-form 1.pdf

483-che-2003-form 26.pdf

483-che-2003-form 3.pdf

483-che-2003-form 4.pdf

483-che-2003-form 5.pdf

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Patent Number

219733

Indian Patent Application Number

483/CHE/2003

PG Journal Number

27/2008

Publication Date

04-Jul-2008

Grant Date

13-May-2008

Date of Filing

12-Jun-2003

Name of Patentee

SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY

Applicant Address

Inventors:

#	Inventor's Name	Inventor's Address
1	LIZYMOL PHILIPOSE PAMPADYKANDATHIL
2	KALLIYANAKRISHNAN VENKATESWARAN

PCT International Classification Number

A61K6/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA