Title of Invention	A RESIN FOR USE IN A DENTINE BONDING AGENT
Abstract	This invention relates to a resin for use in a dentine bonding agent comprising atleast one dimethacrylate resin in a diluent,traces of photoinitiator,accfelerators and inhibitors and optionally traces of stabilisers.

Full Text

FIELD OF THE INVENTION This invention relates to a resin for use in a photopolymerisable dentine bonding agent to be used, and to a method of preparation thereof. OBJECTS OF THE INVENTION It is therefore an ob ject of thi s invention to propose a resin for use in a dentine bonding agent and a process for the preparation thereof, which provides a strong interface for the light curing dental composite to be bonded strongly onto the dentinal surface» It is another object of th is invention to propose a resin for use in a dentine bonding agent with improved sheer strength and tensile strength at the dentine/composite interface * It is a further object of this invention to propose a resin for use in a dentine bonding agent, the application of which drastically reduces the marginal leakage at the dent ine/composite interface. It is yet another object of th is invention to propose a resin for use in a dentine bonding agent which wi11 be cheap and economical to use, compared to imported controls. These and other objects of the invention will be apparent from the ensuing description, BRIEF DESCRIPTION OF THE INVENTION According to th is invention, there is provided a resin for use in a dentine bonding agent comprising at least one dimethacrylate resin in a diluent, a photoiniti ator, traces of acce1 erators and inhibitors, and optionally traces of stabilisers. According to this invention, there is further provided a process for preparing a resin for use in a dentine bonding agent comprising at least one dimethacrylate resin in a diluent, traces of photoinitiator, accelerators and inhibitors and optionally traces of stabi1isers. The dimeth aery late resin is sel ected from Bisphenol &~~&lycidyl methaery1 ate (BIS-GMA), urethane, methaerylate resin, in a proportion of 60-~70*/* by weight. The diluent is a monomethacry 1 ate diluent such as 2-hydroxyethyl methacrylate (HEHA), 2~hydroxy~ propyl methacrylate used in an. awoun-fc of 30-40*4 by weight. The photoinitiator used in the process of the invention initiates polymerisation of the resin when exposed to a visible 1 ight source at 440-480 nm Such a photoiniti ator is a diketone, such as camphorquinone which is present in amounts of 0.1-0.3% wt.'/» of the resin mixture The accelerator used in the resin is a tertiary amine, such as diethyl amino phenethyl alcohol or dimethyl p-toluidine present in ^n amount of 0.01-0.01 wt.54 of the resin mixture The inhibitor used in the resin is butylated hydroxy toluene, us-Bd in amounts of 0.05-0-15 wt.K of the resin mixture (BIS-6MA and HEHA)- The UV-stabiliser used in the renin is selected from phenyl salicylate in combination with/without 2-hydroxy 4-methoxy bensophe-none. The stabiliser is used in amounts of 0.02-0.05 wt.% of the resin mixture BIS~GMA and HEHA)* The invention will now he explained in greater detail with the help of the following non-1imiting example . 5.0153 gm The dent inal surface onto which the composi te is to be adhered is cleaned wel 1 off debris* and etched with a commerc ially available standard etching gel and washed thoroughly to remove any traces of etching gel left. The etching gel helps to create micro-cavities on the surface of the dentinal surface. A thin film/layer of a primer solution of the bonding agent is spread over the surface with a f ine brush and subjected to a flow of a thin jet of moisture and oil-free compressed air to ensure uniform drying and spreading of the primer. It is further kept undisturbed for a certain period of time without air drying, preferably for 20-30 seconds. A thin film/layer of the resin is then applied over the dentinal BUTf ace us i ng a f i n e b rush ensur i ng un i f orm sp r e ad i ng * It is then exposed to a visible light source having a wavelength ranging from 440-480 nm for a time period of 10-20 seconds whereby i t polymerises a hard 1&yer wi th an oxygen inhibited 1ayer at the surface. A subsequent resin 1ayer ap1ication over the f irst 1ayer and curing may be necessary if uniform covering of the ent i re surface has not occurred the f i rst t i me « The composi te is then piac ed on the cured resin surface and photopolymerised by conventional techniques. This leads to a bonding agent which provides a strong interface for the composite to be bonded strongly onto the dentinal surface- The bonding agent has a shear strength of 10-20 HPa and a tensile strength of 5-15 MP a, which is comparabl e wi th commerci ally 11 The resin as claimed in claim 1 wherein said accelerator is used in amounts of '0,01-0«i wt*/* of the resin mixture 12. The resin as claimed in claim i wherein said inhibitors are used in amounts of 0.01-0.1 wt% of the resin mixture 13. The resin as claimed in claim 1 wherein said UV stabiliser is used in amounts of 0.02-0.05 of the resin mixture 14. A process for preparing a dentine bonding agent comprising dissolving at 1 east one dimethaerylate resin in a di luent, a photoinitiator, traces of accelerators ^nd inhibitors, and optionally traces of stabi1isers- accelerators and inhibi tors. 15. The process as c1 aimed in c1 aim 14 wherein said dimethacrylate resin is selected from Bisphenol A-Blycidyl methacrylate , urethane methacrylate resin. 16. The process as claimed in claim 14 wherein said diluent is a mono- or dimethacrylate compound such as 2~hydroxyethyl methacry™ late 9 2™hydroxypropyl methacrylate. 17. The process as claimed in claim 14 wherein said photoinitiator is a diketone such as camphorquinone* .1.8. The process as claimed in claim 14 wherein said accelerator is a tertiary amine such as diethylamino phenethyi alcohol and d i me thy1 p—tolui d i n e. 19. The process as claimed in claim 14 wherein said UV stabiliser is selected from phenyl sal icy 1 ate and optionally 2-hydroy-4-methoxy bensophenone. 20* The process as cl aimed in claim 14 wherein said inhibitor is butylated hydroxy toluene. 21. The process as claimed in claim 14 wherein 60-70% by weight of dimethacrylate resin is used. 22- The process as claimed in claim 14 wherein 30-4054 by weight of diluent is used. 23. The process as cl aimed in claim 14 wherein said photo in itiator is used in amounts of 0.1 to 0.3 wt5£ of the resin mixture 24. The process as claimed in claim 14 wherein said accelerator is used in amounts of 0.01-0.1 wt% of the resin mixture 25. The process as claimed in claim 14 wherein said inhibitors are used in amounts of 0.01-0.1 wt% of the resin mixture 26. The process as claimed in claim 14 wherein said UV stabiliser is used in amounts of 0.02-0.05 wt*4 of the resin mixture (BIS-GMA and HEMA). 27. A resin for uiniw ,'ut a dentine bonding agent substantially as herein described and i1 lustrated. 23, A process for preparing a resin for IUUU An a dentine bonding agent substantially as here in described and illustrated. Dated this 26th day of MAY, 2000. WE CLAIM: 1. A resin for a dentine bonding agent comprising at least one dimethacryiate resin in 60-70% by weight dissolved in a diluent in 30-40% both together constituting the resin mixture, and also containing traces or photoinitiator In 0.1-0.3 w/w% of resin mixture, accelerator In 0.1-1.0% w/w% of resin mixture, inhibitors in 0,01-0 1 w/w% of resin mixture and stabilizers in 0,02-0.05% w/w% of resin mixture, 2. The resin as claimed in claim 1 wherein said dimethacryiate resin is selected from Bisphenol A-Glycidyl methacrylate (BIS-GMA),urethane methacrylate resin, 3. The resin as claimed in claim 1 wherein said diluent Is a mono-or dimethacryiate compound such as 2-hydroxyethyi methacrylate (HEMA), 2-hydroxypropyl methacrylate. 4. The resin as claimed in claim 1 wherein said photoinitiator is a diketone such as camphorquinone. 5. The resin as claimed in claim 1 wherein said accelerator Is a tertiary amine such as diethylamino phenethyi alcohol and dimethyl p-toluidine. 6. The resin as claimed In claim 1 wherein said UV stabiliser Is selected from phenyl salicylate and optionally 2-hydroxy-4-mefhoxy benzophenone. 7. The resin as claimed in claim 1 wherein said inhibitor is butylated hydroxy toluene. 8. The resin as claimed in claim 1 wherein 60-70% by weight of dimethacryiate resin is used. 9. The resin as claimed In claim 1 wherein 30-40% by weight of diluent Is used. 10. The resin as claimed in claim 1 wherein said photoinitiator is used in amounts of 0.1 to 0.3 wt% of the resin mixture (BIS-GMA and HEMA).

Documents:

557-mas-1999- abstract.pdf

557-mas-1999- claims duplicate.pdf

557-mas-1999- claims original.pdf

557-mas-1999- correspondence others.pdf

557-mas-1999- correspondence po.pdf

557-mas-1999- decription complete duplicate.pdf

557-mas-1999- decription complete original.pdf

557-mas-1999- form 1.pdf

557-mas-1999- form 26.pdf

557-mas-1999- form 4.pdf