Title of Invention	A SINGLE SOLUTION BONDING AGENT (SSBA) AND A PROCESS FOR THE PREPARATION THEREOF
Abstract	A single solution bonding agent for use as an adhesive in dental applications comprising pyromellitic glycerol dimethyacrylate (PMGDM) and 2-hydroxy ethyl methacrylate (HEMA), a solvent, a photo-initiator and an accelerator.

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FIELD OF THE INVENTION This invention relates to a single solution bonding agent (SSBA) and a process for the preparation thereof This invention further relates to a single solution bonding agent for use as an adhesive in conservative and orthodontic dentistry. BACKGROUND OF THE INVEN llON Bonding agents have evolved over a period of years from first generation to sixth generation bonding agents. These differ mainly in the chemical formulations mid mode of application during dental treatment. An ideal bonding agent is expected to providd (a) high bond strength to dentine, (b) good biocompatibility to dentinal tissues including pulp, (c) minimize microleakage at the margins of restorations, (d) prevent recurrent caries and marginal staining, (e) be easy to use and minimally technique sensitive, (f) possess agood shelf life, (g) be compatible with a wide range of resins, and (h) have a lov/ film thickness. The dawn of bonding agent technology was established by Buonocore in 1956 when he attempted ionic bonding of composite resins to hydroxyapatitc calcium. However, low bond strength values made scientists develop second generation bonding agents based on chloropbosphate esters, polyurethanes and phosphate esters. Subsequently, third and fourth generation bonding agents were developed with a primer and resin incorporating the total adhesive system. However, ease of application forced scientists to develop single solution bonding agents which incorporated both priming and bonding function using the same solution in a single bottle. Imported siRgle solution bonding agents are available in the market in different chemical formulations. They are extremely costly making bonding agents are Single Bond (3M Co. USA), One-step (Bfsco, USA), Prime & Bond 2.1 (Dentsply, Germany). OBJECTS OF THE INVENTION It is therefore an object of this invention to propose a single solution bonding agent which is easy to use and possess good shelf life. It is a further object of this invention to propose a single solution bonding agent which is economical. These and other objects of the invention will be more apparent from the ensuing description. At the outset of the de.scription which follows, it is to be understood that the ensuing description only iHustrates a particular form of this invention. 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 single solution bonding agent for use as an adhesive in dental applications. According to this invention is further provided a process for the preparation of a single solution bonding agent. In accordance with this inyeutioii, the formulation comprises not m-ore than two polynierisabk monomers, a solvent, a photo-initiator and a tertiary amine- accelerator. First of the two monomers is an acidic monomer such as a carboxylic acid monomer, eg. pyromellitic glycerol dim eth aery late (PMGDM monomer). The pyromellitic dianhydride glycerol dim eth aery late adduct (PMGDM) adhesive resin is made by a process by the reaction of 1 part of pyromellitic dianhydride (PMDA) and greater than 2 parts glycerol dim eth aery late (GDMA). The second of the two monomers is a diluent monomer such as 2-hydroxyethyl methacrylate (HEMA monomer) and the photo-initiator is selected from a group consisting of 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, 1-phenyl 1,2 propane dione and (-) camphorquinone. The tertiarj' amine is selected from compounds such as dimethylamino pheiiethyl alcohol (DMAPEA), 4-N-N-(dimethyl amino) benzoate (4-EDMAB), N-N-dimethyl aminoethyl methacrylate (DMAEMA). The solvent is an aprotic solvent such as methyl ethyl ketone, acetone or diethyl ketone. In accordance with this invention, 20-50% by weight of PMGDM, 5-20% by weight of 2~HEMA, 0.1-1% by weight of photo-initiator and tertiary amine are suitably dissolved in an aprotic soJvent such as methyl ethyl ketone, dimethyl ketone, etc. This formulation is nsed for bonding composite rosins to enamel, dentin or non-precious metal. The formulation is applied using a brush tip onto the dentinal surface of human tooth, previously em cried with SiC paper (600 grit) and etched with an etching gel for 60 sees. The solvent is allowed to evaporate and a second layer is applied and the surface is cured using a light source emitting blue light in the wavelength range 460-480 nm. Composite resin is fixed onto the surface, kept for 24 hrs. at SV^C in distilled water mid shear strength and tensile adhesive strength was measured in a universal testing machine. The shear strength was found tobe in the range of 9-16 MPa and the tensile adhesive strength was found to be in the range of 6-10 MPa. The above bonding agent was applied in a similar manner on non-precious metal surface such as brass when the shear strengtli was found to vary between 30-46 MPa and the tensile adhesive strength between 8-12 MPa. WE CLAIM: 1. A single solution bonding agent for use as an adhesive in dental applications, comprising at least a first and a second polymerisable monomer, a solvent, a photo—initiator and an accelerator. 2- The single solution bonding agent as claimed in claim 1 wherein said first monomer is an acidic monomer such as a carboxylic acid monomer- 3. The- single solution bonding agent as claimed in claim 2 wherein said first monomer is pyromel1itic glycerol dimethacrylate (PHGDM) which is obtained by the reaction of 1 part of pyromel 1 itic dianhydride CPMDA) and greater than 2 parts glycerol dimethacrylate (GDMA) 4. The single solution bonding agent as claimed in claim 1 wherein said second monomer is a diluent monomer such as 2- hydroxyethyl methacrylate (HEMA) monomer. 5. The single solution bonding agent as claimed in claim 1 wherein said solvent is an aprotic solvent such as methyl ethyl ketone, acetone or dimethyIketone. 6- The single solution bonding agent as claimed in claim 1, wherein said photo-initiator is selected from a group consisting of 2,4, 6-trimethylben2oyl-diphenyl—phosphine oxide , 1-phenyl, 1,2-propane dione and camphor quinone. 7- The single solution bonding agent as claimed in claim 1, wherein said accelerator is a tertiary amine compound such as diamethylamino phenethyl alcohol (DMAPEA) 4-N, N- dimethyl amino benzoate 8. The single solution bonding agent as claimed in any one of the preceding claims comprising 20 to 30% by weight of said first monomer, 5 to 20% by weight of said second monomer, 0-1 to 1% by weight of photo-initiators and accelerator in a solvent sufficient to dissolve the monomer, photo-initiator and accelerator. 9- A process for the preparation of a single solution bonding agent as claimed in claim 1 comprising dissolving 20 to 30% by weight of a first monomer, 5 to 20% by weight of a second monomer, 0.1 to 1% by weight of a photo—initiator and tertiary amine are dissolved in an aprotic solvent, to obtain the bonding agent. 10. The single solution bonding agent as claimed in claim 1, which when exposed to visible light source of 460—480 nm wavelength for 10—20 sec polymerizes into a thin film. 11. The single solution bonding agent as claimed in claim 1, which when used for bonding composite to tooth provides a shear strength of 9—16 MPa and tensile strength of 6—10 MPa. 12, The single solution bonding agent as claimed in claim 1, which when used for bonding composite to metal surfaces provides a shear strength of 30-46 MPa and tensile strength of 8 " 12 MPa

Documents:

443-che-2003-claims.pdf

443-che-2003-correspondnece-others.pdf

443-che-2003-correspondnece-po.pdf

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

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

443-che-2003-form 1.pdf

443-che-2003-form 26.pdf

443-che-2003-form 3.pdf

443-che-2003-form 5.pdf

443-che-2003-other document.pdf