Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
2001-06-25
2004-06-08
Dawson, Robert (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C522S026000, C522S027000, C522S028000, C522S049000, C522S067000, C522S099000, C522S170000, C522S908000, C523S115000
Reexamination Certificate
active
06747071
ABSTRACT:
The field of the invention is that of dental compositions. More precisely, the dental compositions used in the context of the present invention can be used for producing dental prostheses and for dental restoration.
Up until now, to produce dental compositions for the preparation of dental prostheses or of dental restoration materials, it is possible to use resins based on photopolymerizable acrylates. These ready-to-formulate products exhibit however upon use problems of irritation and potential problems of toxicity.
In addition, these products have the major disadvantage of causing high volume shrinkage during their polymerization, which makes their use complex and difficult for the production of dental prostheses or of dental restoration materials. Problems of attachment due to the volume shrinkage or to the lack of adherence of the polymers used are in particular observed.
The object of the present invention is to provide novel dental compositions which do not exhibit the disadvantages of the prior art. These novel dental compositions, which are polymerizable and/or crosslinkable in an oral environment, have markedly improved qualities, in particular as regards the very marked reduction in the phenomenon of shrinkage of the dental compositions used for the production of dental prostheses or of dental restoration materials.
The polymerizable and/or crosslinkable dental composition according to the invention comprises:
(1) at least one crosslinkable and/or polymerizable silicone oligomer or polymer which is liquid at room temperature or which is heat-meltable at a temperature of less than 100° C., and which comprises:
at least one unit of formula (FS):
Z—SiR
X
0
—O
(3-a)/2
in which:
a=0, 1 or 2,
R
1
, identical or different, represents an alkyl, cycloalkyl, aryl, vinyl, hydrogeno or alkoxy radical, preferably a C
1
-C
6
lower alkyl,
Z, identical or different, is an organic substituent comprising at least one reactive epoxy, and/or alkenyl ether and/or oxetane and/or dioxolane and/or carbonate functional group, and preferably Z being an organic substituent comprising at least one reactive epoxy and/or dioxolane functional group,
and at least two silicon atoms,
(2) an effective quantity of at least one borate-type photoinitiator,
(3) at least one aromatic hydrocarbon photosensitizer with one or more aromatic nuclei which are substituted or not, having a residual light absorption of between 200 and 500 nm,
(4) and at least one dental filler present in a proportion of at least 10% by weight relative to the total weight of the composition.
According to a first advantageous variant of the present invention, the dental composition is polymerizable and/or crosslinkable under activation by the thermal route and/or by the photochemical route.
In general, the photochemical activation is carried out under UV radiation. More particularly, UV radiation having a wavelength of the order of 200 to 500 nm is used for the production of dental prostheses and UV-visible radiation having a wavelength greater than 400 nm for the production of restoration materials. A wavelength greater than 400 nm allows crosslinking and/or polymerization in an oral environment.
The silicone polymer or oligomer (1) has the advantage, compared with organic resins which are crosslinked by the cationic route, of being transparent to UV-visible light and therefore its use makes it possible to obtain materials which are very thick and whose photocrosslinking occurs in a short time.
The reactive functional groups Z of the silicone polymer or oligomer (1) may be highly varied. However, particularly advantageous dental compositions are obtained when the silicone oligomer or polymer (1) comprises at least one (FS) unit in which Z represents an organic substituent Z1 comprising at least one reactive epoxy, and/or dioxolane functional group, and preferably at least one reactive epoxy functional group.
According to two advantageous alternatives of the present invention, the silicone oligomer or polymer (1) with at least one reactive epoxy and/or dioxolane functional group Z1, and preferably at least one reactive epoxy functional group may:
(i) either comprise only this (these) type(s) of reactive functional group(s) Z1,
(ii) or comprise other reactive functional groups Z such as the reactive alkenyl ether, oxetane and/or carbonate functional groups Z2.
In the case of the first alternative (i), the dental composition may also comprise other silicone oligomers and/or polymers comprising other reactive functional groups Z2 such as alkenyl ether, oxetane and/or carbonate functional groups and optionally reactive functional groups Z1.
By way of examples of reactive functional groups Z, these may in particular be chosen from the following radicals:
with R″ representing a linear or branched C
1
-C
6
alkyl radical.
According to a second advantageous variant of the present invention, the silicone polymer or oligomer consists of at least one silicone having the following average formula:
The cationic photoinitiators are chosen from onium borates (taken on their own or as a mixture with each other) of an element of groups 15 to 17 of the Periodic Table [Chem. & Eng. News, vol. 63, No. 5, 26 of 4 Feb. 1985] or of an organometallic complex of an element of groups 4 to 10 of the Periodic Table [same reference].
The cationic entity of the borate is selected from:
(1) the onium salts of formula (I)
[(R
1
)
n
—A—(R
2
)
m
]
−
(I)
in which formula:
A represents an element of groups 15 to 17 such as for example: I, S, Se, P or N,
R
1
represents a carbocyclic or heterocyclic C
6
-C
20
aryl radical, it being possible for said heterocyclic radical to contain, as heteroelements, nitrogen or sulfur,
R
2
represents R
1
or a linear or branched C
1
-C
30
alkyl or alkenyl radical; said radicals R
1
and R
2
being optionally substituted with a C
1
-C
25
alkoxy, C
1
-C
25
alkyl, nitro, chloro, bromo, cyano, carboxyl, ester or mercapto group,
n is an integer ranging from 1 to V+1, v being the valency of the element A,
m is an integer ranging from 0 to v−1 with n+m=v+1,
(2) the oxoisothiochromanium salts described in patent application WO 90/11303, in particular the sulfonium salt of 2-ethyl-4-oxoisothiochromanium or 2-dodecyl-4-oxoisothiochromanium,
(3) the sulfonium salts in which the cationic entity comprises:
3
1
at least one polysulfonium entity of formula (II.1):
in which:
the symbols Ar
1
, which are identical or different, each represent a monovalent phenyl or naphthyl radical, optionally substituted with one or more radicals chosen from: a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkyl radical, a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkoxy radical, a halogen atom, an —OH group, a —COOH group, an ester group —COO-alkyl where the alkyl portion is a linear or branched C
1
-C
12
, preferably C
1
-C
6
, residue, and a group of formula —Y
4
—Ar
2
where the symbols Y
4
and Ar
2
have the meanings given just below,
the symbols Ar
2
, which are identical or different, each represent a monovalent phenyl or naphthyl radical, optionally substituted with one or more radicals chosen from: a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkyl radical, a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkoxy radical, a halogen atom, an —OH group, a —COOH group, an ester group —COO-alkyl where the alkyl portion is a linear or branched C
1
-C
12
, preferably C
1
-C
6
, residue,
the symbols Ar
3
, which are identical or different, each represent a divalent phenylene or naphthylene radical, optionally substituted with one or more radicals chosen from: a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkyl radical, a linear or branched C
1
-C
12
, preferably C
1
-C
6
, alkoxy radical, a halogen atom, an —OH group, a —COOH group, an ester group —COO-alkyl where the alkyl portion is a linear or branched C
1
-C
12
, preferably C
1
-C
6
, residue,
t is an integer equal to 0 or 1, with the additional conditi
Dawson Robert
Rhodia Chimie
Zimmer Marc
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