Title of Invention

A PROCESS FOR THE PREPARATION OF A PHOTOPOLYMERIZABLE DENTINE BONDING AGENT

Abstract This invention relates to a primer solution for use in a dentine bonding agent comprising an organic acid and an inhibitor dissolved in a methacrylate compound in a carrier.
Full Text

FIELD OF THE INVENTION
This invent ion relates to a primer solution for a photopolymeri-zable dentine bonding agent, and to a method of preparat ion thereof -
OBJECTS OF THE INVENTION
An object of this invention is to propose a primer solution for 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 this invention to propose a primer solution for 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 primer, solution for a dentine bonding agent, the application of which drastically reduces the marginal leakage at the dentine/composite interface.
It is yet another object of this invention to propose a primer solution for a dentine bonding agent which will be cheap and economical to use, compared to imported controls.
These and other objects oi the invention will be apparent from the ensuing description. BRIEF DESCRIPTION OF THE INVENTION
According to this invention, there is provided a primer solution for use in a dentine bonding agent comprising an organic acid and an inhibitor dis-solved in a methacrylate compound in a carrier-

Recording to this invention is further provided a process for the preparation of a primer solution for use in a dentine bonding agent comprising dissolving a methacryiate compound in a carrier solution, adding an organic acid and optionally an inhibitor thereto to obtain the primer solution.
The dentine bonding agent is made of two parts, namely a primer solution forming the subject matter of the instant application and B resin part forming the subject matter of a copending application.
The organic ac id is selected from di acids such as maleic acid and used in a proport ion of 1.8—2.05 by wt • .
The primer solution may also contain an inhibitor such as 4--methoxyphenol, incorporated therein to prevent prepolymerisat ion of the primer solution. The inhibitor is present in an amount of 0.001-0.01% by wt..
The carrier material is selected from a volatile or non-volatile solvent such as distilled water, ethyl alcohol and acetone, used individually or in combination. In an embodiment of the invention, alcohol and distilled water are used in combination, each in a proportion of 30-40X by wt..
The methacryiate ester such as 2-hydroxy ethyl methacryiate is distilled under vacuum before use, and is used in a proportion of 20-35% by wt..
The invention will now be explained in greater detail with the help of the following non-limiting example.

1-413 ml (23.54 phr) of hydroxy ethyl methacry1 ate is dissolved in a mixture of 2-S ml ('35.70 phr) of ethanol and 2.5 ml (38.31 phr) of disti 1 led water. To this solution, 0- 125 gms (1 .94 phr) of maleic ac id and 0.45 mg (0,007 phr) of inhibitor are added and mixed well in a stoppered bottle at room temperature. MODE OF APPLICATION
The dentinal surface onto which the composite is to be adhered is cleaned we11 off debri and etched with a commercially available standard etching gel and washed thoroughly to remove any traces of etching gel left- The etching gel helps to create micro-activities on the surface of the dentinal surface.
A th in f ilm/1ayer of the primer solution of the bounding agent is spread over the surface with a fine 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. A thin film/layer of the resin is then applied over the dentinal surface using a fine brush ensuring uniform spreading. It is then exposed to a visible light source having a wavelength ranging from 440-480 nm for a time period of 10—20 s. A subsequent resin layer application over the first layer and curing may be necessary i f uniform covering of the entire surface has not occurred the first time.
The composi te is then placed on the cured resin surface and photopolymerised by conventional techniques.



WE CLAIM:
I. A primer solution for use in a dentine bonding agent compri
sing an organic acid and an inhibitor dissolved in a methacrylate
compound in a carrier.
2- The primer solution as claimed in claim 1 wherein said organic acid is a dioic acid such as maleic acid.
3. The primer solution as claimed in claim 1 wherein said meth
acrylate compound is 2—hydroethyl methacrylate.
4. The primer Bolut ion as claimed in claim 1 where in said carrier
is a volatile or non—volatile solvent such as distilled water,
ethyl alcohol and acetone, used singly or in combination.
5. The primer solution as claimed in claim 4 wherein the 2-hydroxy ethyl methacrylate is distilled under vacuum before use-
6. The primer solution as claimed in claim 1 wherein said inhibitor is 4-methoxy phenol.
7. The primer solution as claimed in claim 1 wherein said organic
acid is used in a proportion of 1.8 to 2,0% by weight.
S. The primer solution as claimed in claim 1 wherein said methacrylate compound is used in a solvent of 20 to 30% by weight.
9. The primer solution as claimed in claim 1 wherein said carrier
material is used in 30 to 40% by weight.
10. The primer solution as claimed in claim 1 wherein said inhi-
bitor is used in 0.001 to 0.01% by weight.
II. A process for the preparation of a primer solution for use in
a dentine bonding agent comprising dissolving a methacrylate com
pound in a carrier sol vent, adding an organic acid and optionally

an inhibitor thereto to obtain the primer solution.
12. The process as claimed in claim 4 wherein the process i s
carri ed out at room temperature.
13. The process as claimed in claim 11 wherein said organic acid is a dioic acid such as maleic acid-
14. The process as claimed in claim 11 where in said metheery late compound is 2-hydroethyl methacrylate.
15. The process as claimed in claim 11 wherein said carrier is a volatile or non-volatile solvent such as distilled water, ethyl alcohol and acetone, used singly or in combination.
16. The process as claimed in claim 15 wherein the 2-hydroxy
ethyl methacrylate is distilled under vacuum before use.
17. The process as claimed in claim 11 wherein said inhibitor is
4-methoxy phenol.
18- The process as claimed in claim 11 wherein said organic acid is used in a proportion of 1.8 to 2.0% by weight-
19. The process as claimed in claim 11 wherein said methacrylate
compound is used in a solvent of 20 to 30% by weight.
20. The process as claimed in claim 11 wherein said carrier
material is used in 30 to 40% by weight.
21. The process as claimed in claim 11 wherein said inhibitor is used in 0.001 to 0.01% by weight.
22. A primer solution for use in a dentine bonding agent substantially as herein described and illustrated.

23. A process for the preparation of a primer solution for use in a dentine bonding agent substantially as herein described and i 1 lustrated-
Dated this 29th day of MAY, 2000-


Documents:

558-mas-1999-abstract.pdf

558-mas-1999-claims duplicate.pdf

558-mas-1999-claims original.pdf

558-mas-1999-correspondance others.pdf

558-mas-1999-correspondance po.pdf

558-mas-1999-description complete duplicate.pdf

558-mas-1999-description complete original.pdf

558-mas-1999-description provisinol.pdf

558-mas-1999-form 1.pdf

558-mas-1999-form 26.pdf

558-mas-1999-form 6.pdf


Patent Number 206791
Indian Patent Application Number 558/MAS/1999
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 11-May-2007
Date of Filing 13-May-1999
Name of Patentee SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY
Applicant Address SATELMOND PALACE, TRIVANDRUM-695 012.
Inventors:
# Inventor's Name Inventor's Address
1 VENKATESWARAN KALLIYANAKRISHNAN SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY SATELMOND PALACE, TRIVANDRUM-695 012.
2 PAMPADYKANDATHIL PHILIP LIZYMOL SREE CHITRA TIRUNAL INSTITUTE FOR MEDICAL SCIENCES & TECHNOLOGY SATELMOND PALACE, TRIVANDRUM-695 012.
PCT International Classification Number C08F120/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA