Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Reexamination Certificate
2002-02-07
2004-01-13
Killos, Paul J. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
C560S064000
Reexamination Certificate
active
06677474
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a group of novel dimethacrylate compounds which can be used alone or in conjunction with other compounds, and which are useful as components in bonding systems for dental use, and to bonding systems incorporating such components which have superior adhesion to a variety of dental substrates.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention, there is provided a group of novel dimethacrylate compounds produced by the reaction of unsaturated alcohols with 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride), also known as bisphenol A dianhydride. Bisphenol A dianhydride has the following structural formula:
The unsaturated alcohols useful in the invention are those having the formula:
wherein R
1
is H, CH
3
, or═CH
2
; R
2
is H or CH
3
; n is 1, 2, 3, or 4; and x is 0 or 1.
The reaction product produced in this manner is used in accordance with the invention in conjunction with other compounds such as a dentin conditioner or other components of a dental composite material. These materials are applied in solution to an area in which a bond is desired. The bond is usually completed by use with a self-curing initiator or a light cure system.
DETAILED DESCRIPTION OF THE INVENTION
The difunctional compounds of the present invention are, in general, symmetrical compounds having a polyaromatic nucleus substituted with two acrylate groups. Representative of the difunctional compounds of the present invention are those having the following structure:
wherein R
2
is H or CH
3
.
The novel diacrylate compounds are produced by a reaction of unsaturated alcohols with a cyclic dianhydride which has the following structure:
This cyclic dianhydride compound is produced by General Electric Co. under the name bisphenol A dianhydride and may be purchased from the Aldrich Chemical Co. under the name of 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride). For producing the novel bonding agent components in accordance with the invention, the cyclic dianhydride as described above is permitted to react in the presence of a small amount of a tertiary amine such as triethylamine, with preferably at least two molar equivalents of an unsaturated alcohol having the formula II.
The preferred unsaturated alcohols used in making the components of the invention are hydroxyethyl methacrylate and hydroxypropyl methacrylate. When these alcohols are reacted with suitable anhydrides in accordance with the invention, there is produced a group of preferred compounds having the formula:
wherein R
2
is H or CH
3
.
An example of the preparation of an unsaturated alcohol-cyclic dianhydride product is given in the following reaction, in which symmetrical dianhydride (I) is reacted with two moles of hydroxyethyl methacrylate.
The difunctional product, 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalate dimethacrylate ester) (IDBM, III) illustrated in the above reaction and its analogs may be one component of a novel dental bonding composition in accordance with the invention. The novel dental bonding compositions of the present invention and methods for their use have particular application in the field of restorative dentistry.
A preferred bonding system comprises (a) a dentin conditioner which is the reaction product of a cyclic acid anhydride having 3-12 carbon atoms with an ethylenically unsaturated alcohol having 3-12 carbon atoms, as disclosed in our U.S. patent application Ser. No. 07/471,882, now abandoned, and (b) a two-part dentin primer, the first part of which comprises the reaction product of an N-arylglycine with glycidyl methacrylate, having the formula:
wherein R is hydrogen or H or CH
3
.
When R is CH
3
, the reaction product (V) is designated as NTG-GMA, and when R is H, as NPG-GMA. The second part of the two-part primer is selected from products, such as IDBM or its analogs disclosed afore.
Other preferred compositions according to the present invention comprise a difunctional compound (III), a filler portion, a polymerization catalyst portion comprising a polymerization compound or system. Optionally, the compositions may also include an additional multifunctional and/or monofunctional comonomer portion, antimicrobial agents, opaquifiers, fluoride-release agents, colorants and other components, which impart desirable properties to the composition. Such additional agents may be incorporated into one or more of the monomer, comonomer or filler portions of the compositions, or may be added in small amounts to the composition during formulation. Difunctional compounds (III) are used to build up a better cross-linking structure in the polymer matrix. This structure plays a very important role in the mechanical properties of the dental materials.
Presently preferred amounts of difunctional compound (III) in compositions of the present invention are from about 5 to about 35 weight percent of the total composition. Presently more preferred amounts are in the range of about 10 to about 25 weight percent of the composition.
Preferred fillers according to the present invention include one or more well-known sub-micron size fillers. For example, sub-micron size fillers are silanated oxides of aluminum, zirconium and silicon, silicate glasses, and barium or strontium glasses. The use of sub-micron size fillers is presently preferred to minimize surface wear and “plucking” of filler components from the restorative surface, as well as imparting a surface which may be easily polished by the dental professional. Preferred contemplated filler particles have an average size of about 0.04 to about 40 microns. Presently more preferred fillers have an average particle size of about 0.05 to about 10 microns.
The filler portion may also include caries inhibiting agents such as slow releasing fluoride agents to help inhibit caries from forming in the adjacent tooth structure. For example, glass ionomer 1X 1944 from Ferro Corporation, Cleveland, Ohio, which contains such a slow release fluoride agent, is expected to have utility in the present invention.
The filler or fillers are present at about 75 to about 95 weight percent of the contemplated compositions of the present invention, and are more preferably present at about 80 to about 90 weight percent of the composition. The amount of the filler component is adjusted in view of the other components of the composition and in view of the intended use of the composition, it being well known in the art that higher filler amounts generally impart higher compressive strengths to a composition, but also tend to increase viscosity and decrease flowability of the composition. Presently preferred fillers include silanized barium glass from Ferro Corporation, Cleveland, Ohio, silanized submicron glasses such as OX-50 or Aerosil R972 from DeGussa, Richfield Park, N.J., and porcelain ground (SR) glass such as (RWG) from Ferro Corporation, Cleveland, Ohio.
Optionally, the filler portion is formulated to include appropriate coloring agents in varying amounts to provide the dental professional with a range of colors in the composition, which may be selected for compatibility with the shade of the patient's tooth undergoing restoration. Such coloring or tint agents are well known in the art, and may be included in small amount of about 1 weight percent or less of the total composition. Such fillers can also be selected to be radioopaque. For example, appropriate amounts of radioopaque barium, strontium or zirconium glass may be used as all or part of the filler portion, which can assist the dental professional in his or her post-treatment examination of the patient.
A polymerization catalyst compound, composition or system is also included in the preferred compositions of the present invention. Such polymerization compounds compositions or systems (hereinafter referred to as “systems”) are well known in the art.
They generally fall within one of three categories: (1) self-curing chemical systems, which initiate polymerization upon admixing two o
Hamer Martin
Suh Byoung In
Tiba Amer
Bisco Inc.
Howrey Simon Arnold & White , LLP
Killos Paul J.
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