FR2842098A1 - A composition for use in dental prostheses and fillings comprises a UV activated resin, a dental filler, a dispersant, cationic initiator and optionally a photosensitizer - Google Patents

Abstract

A dental composition comprising an actinically activated cationically reactive compound, a dental filler at 10 wt.% or more, a dispersant based on a (co)polymer with an amine index of 100 mg of potassium per gram, one or more cationic initiators and optionally a photosensitizer. Independent claims are included for a dental prosthesis obtainable from the claimed composition and for a dental filling obtainable from the composition.

Description

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Highly stable and stable cationic curable / crosslinkable dental composition
The field of the invention is that of dental compositions. More specifically, the dental compositions developed in the context of the present invention can be used for producing dental prostheses and for dental restoration.

 These dental compositions are conventionally epoxy resins, or photopolymerizable silicones or radical-polymerizable acrylate resins. These compositions also include particulate reinforcing fillers (eg hydrophobized silica), photoinitiators and optionally photosensitizers with respect to cationic compositions and radical initiators with regard to radical compositions, or even other functional additives such as pigments or stabilizers.

Once mixed, these compositions are shaped and photocrosslinked into a mass of structure similar to that of the teeth.

The fact that the filler consists of very fine particles (0.05 m) and large surface area, is a limiting factor of its incorporation rate in the resin. The latter has a limited absorption capacity. As a result, the charge levels of such compositions seldom reach more than 45% by volume.

This therefore penalizes the mechanical reinforcement function assigned to the particulate load.

The latter can also interact with the reactive functions of the (photo) polymerizable / crosslinkable species and thus be the cause of instability problems of the dental composition.

US-B-6,306,926 relates to dental compositions based on epoxy resins (eg polyTetraHydroFurane, UVR # 6105, EPON 828, GY281), oxetane, or vinyl ether, inter alia, polymerizable / crosslinkable, cationically and under irradiation and optionally radically polymerizable (meth) acrylate resins. In addition to the polymerization inductors that are cationic photoinitiators and optionally radical initiators as the case may be, these compositions comprise a microparticulate, radioopaque mineral filler, which is selected from the following metal compounds: oxides, halides, borates phosphates, silicates, carbonates, germanates , tetrafluoroborates, hexafluoro-phosphates, having an isoelectric point less than 7. This composition is such that its Barcol hardness of at least 10, after 30 min of cationic polymerization at 25 C.

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These resins have the disadvantage of not being perfectly transparent to the actinic radiation activating the UV-visible actinic polymerization, which is detrimental to the reaction kinetics and therefore limits the possibilities of obtaining very thick photoreactive materials.

une quantité efficace d'au moins un amorceur de type borate d'onium:

au moins un photosensibilisateur, et une charge dentaire ou de renforcement inerte à base de polyméthacrylate de méthyle ou de silice de combustion traitée hexaméthyldisilazane de surface spécifique 200 m2/g, présente dans la composition dans une proportion d'au moins 10% en poids par rapport au poids total de la composition. Ces compositions dentaires sont destinées à la fabrication de prothèses ou d'appareils dentaires. The patent application FR-A-2 784 025 aims to remedy this by proposing dental compositions based on polymerizable / crosslinkable silicone resins, cationically and under irradiation followed or not by a thermal post-crosslinking. These silicone resins have oxirane (epoxide, oxetane, etc.) or vinyl ether functional groups. Such compositions comprise one or more crosslinkable and / or cationically polymerizable polydimethylsiloxanes carrying at least one of their ends with reactive functions. of formula:

an effective amount of at least one onium borate initiator:

at least one photosensitizer, and an inert reinforcing or dental filler based on polymethylmethacrylate or hexamethyldisilazane-treated fumed silica with a specific surface area of 200 m 2 / g, present in the composition in a proportion of at least 10% by weight per relative to the total weight of the composition. These dental compositions are intended for the manufacture of prostheses or dental appliances.

These silicones have the advantage over organic resins crosslinking cationically to be very transparent to UV-visible light and therefore to allow the production of very thick materials (several millimeters thick) photocrosslinked in very few cases. time (less than one minute) with a UV lamp emitting in the visible range> 400 nm.

However, these silicones are formulated with Lewis or Bronsted acidic reinforcing fillers, such as quartz or silica of very small particle size combustion, whose surface silanols and / or residual water, react with the functions cationic. Such silicone formulations are therefore unstable in the storage of the compositions.

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 In addition to this problem of instability generated by the charges, these silicone dental compositions remain perfectible with regard to the increase of the charge rate, so as to allow the improvement of the mechanical properties.

R-I-CO-(CH2)5-0-1,-PO3H2 Un tel enseignement relatif à des compositions dentaires radicalaires n'est nullement transposable aux compositions dentaires cationiques à base de silicone. En effet, les

dispersants R-[-CO-(CH2)5-O-]n-PO3H2 ne sont pas adaptés aux compositions cationiques, notamment car ils contiennent un résidu acide RP03H2 important qui réagit en présence de fonctions oxiranes et nuit à la stabilité de la composition. Furthermore, patent application EP-A-1 050 291 discloses highly loaded dental compositions which are presented as having good mechanical properties and comprising from 10 to 70% by volume of filler (eg combustion silica). particle size # m of which 0.05-0.5 m (less than 50% by volume of particles of diameter 0> 0.50 m), a radical-photopolymerizable acrylic monomer and a phosphoric acid ester-type dispersant of formula :

RI-CO- (CH2) 5-0-1, -PO3H2 Such a teaching relating to radical dental compositions is in no way transposable to cationic dental compositions based on silicone. Indeed,

Dispersants R - [- CO- (CH 2) 5 -O-] n -PO 3 H 2 are not suitable for cationic compositions, especially since they contain an important acidic residue RPO 3 H 2 which reacts in the presence of oxirane functional groups and impairs the stability of the composition .

It therefore appears that the prior art does not provide a satisfactory solution to the double problem of stabilization of dental compositions based on cationically polymerizable units under UV (for example oxiranes) and dispersion of large amounts of fillers in the resin. .

 One of the essential objectives of the present invention is therefore to remedy this by providing new dental compositions based on cationically polymerizable units under UV (for example oxiranes), not having the disadvantages of the prior art on the plan of stability and the limited load rate.

 Another essential objective of the present invention is to provide new cationic dental compositions, polymerizable and / or crosslinkable in the oral environment, which are not only stable and heavily loaded (eg> 50%) but which also have significantly improved qualities, especially with regard to the very clear reduction of the phenomenon of removal of the dental compositions used for the production of dental prostheses or dental restoration materials.

 Another essential objective of the present invention is to provide new cationic, polymerizable and / or crosslinkable dental compositions in the environment.

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 oral, which are not only stable and heavily loaded (eg # 50%) but which also have the advantage of being very transparent to UV-visible light and thus allow to obtain very thick materials (several millimeters of thickness) photocrosslinked in a very short time (less than one minute) with a UV lamp emitting in the visible range> 400 nm.

 Another essential objective of the present invention is to provide new cationic dental compositions, polymerizable and / or crosslinkable in the oral environment, which are not only stable and heavily loaded (e.g. # 50%) but are also easy to prepare and economical.

These objects, among others, are achieved by the present invention which firstly relates to a dental composition comprising: (1) at least one cationically reactive and activated, preferably actinic, compound; (2) at least one dental load present in a proportion of at least
10% by weight relative to the total weight of the composition; (3) at least one dispersant based on at least one organic polymer or copolymer chosen from those whose amine number is less than or equal to 100 mg of potassium hydroxide per gram of dispersant; (4) at least one cationic photoinitiator; (5) and optionally at least one photosensitizer.

 It is the merit of the inventors to have shown, surprisingly and unexpectedly, that it is possible to use during formulation carefully chosen dispersants (co) polymers, which make it possible to treat the surface of the load and to increase thus the charge rate and therefore ultimately strengthen the material without harming the stability of the composite.

This stability translates into a limited period of use of several months or years.

These dispersants make it possible to thin the material without opacifying it while maintaining a very high stability of the compositions. It is thus possible to use very small quantities of treated filler of very small particle size # 50%.

This technical solution is all the more interesting because it is economically viable and easy to implement.

It is also interesting to note that this composition is satisfactory in terms of limiting the shrinkage after polymerization / crosslinking, which is quite appreciable in the dental application.

 In general, the photochemical activation is carried out under U.V radiation. More particularly, a U.V radiation of wavelength of the order of 200.degree.

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 500 nm for the production of dental prostheses and a visible U.V radiation of wavelength greater than 400 nm for the realization of restoration materials. A wavelength greater than 400 nm allows crosslinking and / or polymerization in an oral environment.

 Actinic (photochemical) activation may be advantageously completed (or even replaced) by thermal activation.

 Preferably, the amine number of the dispersant (3) is less than or equal to 60, and more preferably still between 0.1 and 50 mg of potash per gram of dispersant (3).

 Advantageously, the acid number of the dispersant is less than or equal to 200, preferably less than or equal to 100, and more preferably between 1 and 60 mg of potash per gram of dispersant.

 According to an advantageous characteristic of the invention, the dental load (2) is present in a proportion of 10 to 85% by weight or by volume.

 According to the invention, the dispersant (3) is selected from the group comprising: polyurethane / acrylate copolymers optionally salified with an alkylammonium, acrylic copolymers optionally salified with an alkylammonium, monodiesters of carboxylic acids, polyesters, polyethers polyurethanes, modified polyurethanes, polyol polyacrylates, copolymers thereof or mixtures thereof.

SOLSPERSEE (de la société Avecia) conviennent particulièrement à l'invention. Dispersants marketed under the trademark DISPERBYK (from Byk) or

SOLSPERSEE (from the company Avecia) are particularly suitable for the invention.

In particular and by way of examples, mention may be made of commercial products: Disperbyk 164, Disperbyk 161, Disperbyk166, Disperbyk2070, Disperbyk # 9075, Disperbyk 9076.

US Pat. No. 5,882,393 describes dispersants based on polyurethanes / imidazolesacrylates or epoxides.

US-B-5,425,900 discloses dispersants based on polyurethanes. US-B-4,795,796 discloses polyurethane / polyoxyalkylene glycol monoalkyl ether dispersants.

Patent Application WO-A-99/56864 discloses polyurethane / poly (oxyalkylene carbonyl) dispersants derived from ε-caprolactone and valerolactone.

EP-B-0 403 197 discloses graft polyol-polyacrylate dispersants comprising a polyurethane / polyvinyl-polyacrylate random copolymer and a polyoxyalkylene polyether.

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 Quantitatively speaking, the dispersant (3) is present at 50 ppm to 1%, preferably 100 ppm to 5000 ppm.

 Preferably, the cationically reactive compound (1) is selected from the group of monomers and / or (co) polymers comprising: epoxies, vinyl ethers, oxetanes, spiroorthocarbonates, spiroorthoesters and combinations thereof.

More preferably still, the cationically reactive compound (1) is constituted by at least one crosslinkable and / or polymerizable silicone oligomer or polymer which is liquid at room temperature or hot melt at a temperature of less than 100 ° C. and comprises: # at least one unit of formula (FS):
Z-Si-O (30a) / 2 (R) a in which: -a = 0, 1 or 2, - R, which may be identical or different, represents an alkyl, cycloalkyl, aryl, vinyl, hydrogen or alkoxy radical, preferably C1-C6 lower alkyl, which is identical or different, is an organic substituent comprising at least one epoxy reactive functional group, and / or alkenyl ether and / or oxetane and / or dioxolane and / or carbonate functional groups, and at least two atoms of silicon.

This silicone polymer or oligomer (1) has the advantage over cationically crosslinking organic resins of being transparent to UV-visible light and therefore its use makes it possible to obtain very thick materials and whose photocrosslinking performs in a short time.

 The reactive functions Z of the silicone polymer or oligomer (1) can be very varied. However, particularly advantageous dental compositions are obtained when the oligomer or silicone polymer (1) comprises at least one unit (FS) in which Z represents an organic substituent Z1 comprising at least one epoxy reactive functional group, and / or dioxolane, and preferably at least one epoxy reactive function.

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 According to two advantageous alternatives of the present invention, the silicone oligomer or polymer (1) with at least one epoxy reactive functional group Z1, and / or dioxolane, and preferably at least one epoxy reactive functional group may: (i) either comprise only (s) Reactive function (s) Zl; (ii) or comprise other reactive functions Z such as the reactive functions Z2 alkenyl ether, oxetane and / or carbonate.

 In the case of the first alternative (i), the dental composition may also comprise other oligomers and / or silicone polymers comprising other reactive functions Z2 such as alkenyl ether, oxetane and / or carbonate functional groups and optionally reactive functional groups Z1 .

- avec R" représentant un radical alkyle linéaire ou ramifié en C1-C6. As examples of reactive functions Z, these can be chosen in particular from the following radicals:

with R "representing a linear or branched C1-C6 alkyl radical.

According to a second advantageous variant of the present invention, the silicone polymer or oligomer is constituted by at least one silicone of average formula:

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Different types of fillers (2) can be used to prepare the compositions according to the invention. The fillers are chosen according to the end use of the dental composition: these affect important properties such as appearance, penetration

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 U.V radiation, as well as the mechanical and physical properties of the material obtained after crosslinking and / or polymerization of the dental composition.

 As a reinforcing filler, it is possible to use treated or untreated pyrogenic silica fillers, amorphous silica fillers, quartz, glasses or non-vitreous fillers based on oxides of zirconium, barium, calcium and fluorine. aluminum, titanium, zinc, borosilicates, aluminosilicates, talc, spherosil, yttrium trifluoride, polysaccharides in the form of ground powder such as inert or functionalized polymethylmethacrylates, polyepoxides or polycarbonates.

By way of example, mention may be made of: - inert fillers based on polymethyl methacrylate LUXASELF of the company
UGL usable in the dental field and pigmented in pink, - hexamethyldisilazane-treated combustion silica fillers with a specific surface area
200 m 2 / g, - loads of untreated fumed silica (aerosil AE200 marketed by
DEGUSSA), quartz or glasses of silicon oxides.

According to an advantageous variant of the invention, the fillers and in particular the silica fillers are treated before use at 120 ° C. with an amount of less than 10% w / w of silicone comprising at least one unit of formula (XXIII):
Z-Si-O (3-a) / 2 (RO) a - such that Z 'has the same definition as Z -a = 0, 1, 2 or 3 - with at least one silicon atom.

 The cationic photoinitiators are chosen from onium borates (taken alone or mixed with one another) of an element from groups 15 to 17 of the periodic classification [Chem. & Eng. News, vol.63, No. 5.26 of 4 February 1985] or an organometallic complex of an element from groups 4 to 10 of the Periodic Table [same reference].

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L(R1)n - A - (R2)m+ (I) formule dans laquelle : # A représente un élément des groupes 15 à 17 tel que par exemple : I, S, Se, P ou
N, # R représente un radical aryle carbocyclique ou hétérocyclique en C6-C20, ledit radical hétérocyclique pouvant contenir comme hétéroéléments de l'azote ou du soufre, # R représente R ou un radical alkyle ou alkényle linéaire ou ramifié en C1-C30 ; lesdits radicaux R et R étant éventuellement substitués par un groupement

alcoxy en Ci-c 25' alkyle en C1-C25, nitro, chloro, bromo, cyano, carboxy, ester ou mercapto, # n est un nombre entier allant de 1 à v + 1, v étant la valence de l'élément A, . m est un nombre entier allant de 0 à v -1 avec n + m = v + 1, (2) les sels d'oxoisothiochromanium décrits dans la demande de brevet
WO 90/11303, notamment le sel de sulfonium du 2-éthyl-4- oxoisothiochromanium ou de 2-dodécyl-4-oxoisothio-chromanium, (3) les sels organométalliques de formule (III) :

(L 1 L Z L 3 M)+ formule dans laquelle : # M représente un métal du groupe 4 à 10, notamment du fer, manganèse, chrome, cobalt, # Lreprésente 1 ligand lié au métal M par des électrons #, ligand choisi parmi les

ligands r3-alkyl, il5- cyclopendadiènyl et 117- cycloheptratriènyl et les composés
116 - aromatiques choisis parmi les ligands 116-benzène éventuellement substitués et les composés ayant de 2 à 4 cycles condensés, chaque cycle étant capable de contribuer à la couche de valence du métal M par 3 à 8 électrons #, # L représente un ligand lié au métal M par des électrons #, ligand choisi parmi

les ligands 117 -cycloheptatriènyl et les composés 116-aromatiques choisis parmi les ligands #6- benzène éventuellement substitués et les composés ayant de 2 à 4 The cationic entity of the borate is selected from: (1) the onium salts of formula (I):

L (R 1) n - A - (R 2) m + (I) wherein: # A represents an element of groups 15 to 17 such as for example: I, S, Se, P or
N, # R represents a C6-C20 carbocyclic or heterocyclic aryl radical, said heterocyclic radical possibly containing heteroelements of nitrogen or sulfur, # R represents R or a linear or branched C1-C30 alkyl or alkenyl radical; said radicals R and R being optionally substituted by a group

C 1 -C 25 alkoxy, C 1 -C 25 alkyl, nitro, chloro, bromo, cyano, carboxy, ester or mercapto, # n is an integer from 1 to v + 1, where v is the valence of element A ,. m is an integer ranging from 0 to v -1 with n + m = v + 1, (2) the oxoisothiochromanium salts described in the patent application
WO 90/11303, especially the sulphonium salt of 2-ethyl-4-oxoisothiochromanium or 2-dodecyl-4-oxoisothio-chromanium, (3) the organometallic salts of formula (III):

(L 1 LZL 3 M) + formula in which # M represents a metal of group 4 to 10, especially iron, manganese, chromium, cobalt, # Lrepresente 1 ligand bound to the metal M by electrons #, ligand chosen from

R3-alkyl, il5-cyclopendadienyl and 117-cycloheptratrienyl ligands and compounds
116 - aromatics selected from optionally substituted 116-benzene ligands and compounds having 2 to 4 fused rings, each ring being capable of contributing to the valence layer of metal M by 3 to 8 electrons #, # L represents a bound ligand to the metal M by electrons #, a ligand chosen from

117-cycloheptatrienyl ligands and 116-aromatic compounds selected from optionally substituted 6-benzene ligands and compounds having 2 to 4

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condensed rings, each cycle being capable of contributing to the valence layer of the metal M by 6 or 7 electrons #, # L represents from 0 to 3 identical or different ligands bound to the metal M by electrons #, ligand (s) chosen ( s) among CO and NO2 +; the total electronic charge q of the complex to which L, L2 and L contribute and the ionic charge of the metal
M being positive and equal to 1 or 2.

The borate anionic entity has the formula [BXa Rb] - in which: a and b are integers ranging from 0 to 3 and for b from 1 to 4 with a + b = 4, the X symbols represent a halogen atom (chlorine, fluorine) with a = 0 to 3, an OH function with a = 0 to 2, the symbols R are identical or different and represent: a phenyl radical substituted with at least one an electron-withdrawing group such as, for example, OCF 3, CF 3, NO 2, CN, and / or with at least 2 halogen atoms (especially fluorine), and this when the cationic entity is an onium of a group 15 to 17 element a phenyl radical substituted by at least one element or an electron-withdrawing group, especially a halogen atom (especially fluorine),
CF3, OCF3, NO2, CN, and this when the cationic entity is an organometallic complex of a group of elements 4 to 10, # an aryl radical containing at least two aromatic rings such as for example biphenyl, naphthyl, optionally substituted by at least one element or an electron-withdrawing group, in particular a halogen atom (especially fluorine), OCF3, CF3, NO2, CN, whatever the cationic entity.

 Without this being limiting, are given below more details on subclasses of onium borate and borate of organometallic salts more particularly preferred in the context of the use according to the invention.

According to a first preferred variant of the invention, the species of the borate anionic entity which are particularly suitable are the following: 1 ': [B (C 6 F 5) 4] - 5': [B (C 6 H 3 (CF 3) 2) 4 ] -
2 ': [(C6F5) 2BF2] - 6': [B (C6H3F2) 4] -

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 3 ': [B (C6H4CF3) 4] - 7': [C6FSBF3] - 4 ': [B (C6F40CF3) 4] -.

[()2+ [C8H17-O--I-]+ [CH3-<D-I-<D-CH2CH(CH3h]+ ; [C12 H25--I-]+ [(C8H17-O-)21 z [(C8H17-O-' I-<D)]+; [(0)3 S]+ [()2-S--O-C8H17]+ LCH3--I--CH(CH3)2]+ [-s--S-()2]+ LC12H25-)21]+ [(CH3--I--OC2H5]+ [(Ci2H25-O-I-O-CH-(CH3)2]+ . According to a second preferred variant of the invention, the onium salts (1) which can be used are described in numerous documents, in particular in US-A-4,026,705, US-A-4,032,673 and US-A-4. 069,056, US-A-4,136,102, US-A-4,173,476. Of these, the following cations will be particularly preferred:

[() 2+ [C8H17-O-I-] + [CH3- <DI- <D-CH2CH (CH3h] +; [C12 H25 - I -] + [(C8H17-O-) 21 z [( C8H17-O- 'I- <D)] + [(O) 3 S] + [() 2-S-O-C8H17] + LCH3 - I - CH (CH3) 2] + [-s --S - () 2] + LC12H25-) 21] + [(CH3-I-OC2H5] + [(C12H25-O10-CH- (CH3) 2] +.

. le (115 - cyclopentadiènyle) (116 - cumène) Fe+ . le bis (#6- mesitylène) Fe+, . le bis (Il 6 - benzène) Cr+
En accord avec ces trois variantes préférées, on peut citer, à titre d'exemples de photoamorceurs du type borates d'onium, les produits suivants :

[(C8H17)-O--I-)]+ [B(C6F5)4]- ; [C 12H25--I-]+ [B(C6F5)4]- ; [(C8H17-O-)2I]+ [B(C6F5)4]- ; LC8H17)-O--I-)]+ [B(C6F5)4]- ; [(<DhS-<D-O-CSH17]+ , [B(C6H4CF3)4]- ; [(C 12H25-)2I]+ [B (C6F5)4]- [CH3--I--CH(CH3)2]+ , [B(C6F5)4]' ; (115 - cyclopentadiènyle) (116 - toluène) Fe+, [B(C6F5)4]~ ; (115 - cyclopentadiènyle) (116 - methyl-1 -naphtalène) Fe+, [B(C6F5)4] ; (r15 - cyclopentadiènyle) (Il 6 - cumène) Fe+, [B(C6F5)4] ; [C12H25-)2I]+ [B(C6H3(CF3)2]- ; According to a third preferred variant, the organometallic salts (4) which can be used are described in the documents US-A-4,973,722, US-A-4,992,572, EP-A-203,829, EP-A-323,584 and A-354 181. The organometallic salts more readily selected according to the invention are in particular: (II 5 -cyclopentadienyl) (he 6-toluene) Fe +,. (# -cyclopentadienyl) # 6-methyl-1-naphthalene) Fe +,

. (115-cyclopentadienyl) (116-cumene) Fe +. bis (# 6- mesitylene) Fe +,. bis (II 6 - benzene) Cr +
In accordance with these three preferred embodiments, there may be mentioned, as examples of photoinitiators of the onium borate type, the following products:

[(C8H17) -O-I -)] + [B (C6F5) 4] -; [C 12 H 25 - I -] + [B (C 6 F 5) 4] -; [(C8H17-O-) 2I] + [B (C6F5) 4] -; LC8H17) -O - I -)] + [B (C6F5) 4] -; [(<DhS- <DO-CSH17] +, [B (C6H4CF3) 4] -; [(C12H25-) 2I] + [B (C6F5) 4] - [CH3-I-CH (CH3) 2 ] +, [B (C6F5) 4] (115 - cyclopentadienyl) (116 - toluene) Fe +, [B (C6F5) 4] - (115 - cyclopentadienyl) (116 - methyl - 1 - naphthalene) Fe +, [ B (C6F5) 4]; (r15-cyclopentadienyl) (11-cumene) Fe +, [B (C6F5) 4]; [C12H25-) 2I] + [B (C6H3 (CF3) 2] -;

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[CH3--I--CH2CH(CH3)2J+ , [B(C6F5)4]- ; [CH3--I--CH2CH(CH3)2J+ , [B(C6H3(CF3)2)4]-.

[CH 3 - I - CH 2 CH (CH 3) 2] +, [B (C 6 F 5) 4] -; [CH3 - I - CH2CH (CH3) 2] +, [B (C6H3 (CF3) 2) 4] -.

 As another literary reference for defining the onium borates (1) and (2) and the borates of organometallic salts (4), mention may be made of the entire content of the patent applications EP 0 562 897 and 0 562 922. This Content is fully incorporated by reference in this specification.

 As another example of onium salt used as photoinitiator, mention may be made of those disclosed in US Pat. Nos. 4,138,255 and 4,310,469.

- [CH3--I--CH(CH3)2J+ [PF6]- ; - [CH3--I--CH2CH(CH3)2J+ [PF6]- ; - IC12H25-D)2-I]+, [PF6]-; - ou les sels de ferrocénium de ces différents anions. It is also possible to use other cationic photoinitiators, eg: iodonium hexafluorophosphate or hexafluoro-antimonate salts, such as:

- [CH 3 - I - CH (CH 3) 2] + [PF 6] -; - [CH3 - I - CH2CH (CH3) 2J + [PF6] -; - IC12H25-D) 2-I] +, [PF6] -; or the ferrocenium salts of these different anions.

# formule (IV) dans laquelle : - lorsque n = 1, Ar1 représente un radical aryle contenant de 6 à 18 atomes de carbone, un radical tétrahydronaphtyle, thiényle, pyridyle ou furyle ou un radical phényle porteur d'un ou plusieurs substituants choisis dans le groupe constitué de F, Cl, Br, CN, OH, les alkyles linéaires ou ramifiés en C1-C12, -
CF3, -OR6,-OPhényle, -SR6, -SPhényle, -S02Phényle, -COOR6,

-O-(CH2-CH=CH2), -O(CH2Hq.-O)m-H, -O(C3H60)m-H, m étant compris entre 1 et 100, The photosensitizer contained within the dental composition according to the invention can be very varied in nature. In the context of the invention, it corresponds in particular to one of the following formulas (IV) to (XXII):

formula (IV) in which: when n = 1, Ar 1 represents an aryl radical containing from 6 to 18 carbon atoms, a tetrahydronaphthyl, thienyl, pyridyl or furyl radical or a phenyl radical bearing one or more substituents chosen from the group consisting of F, Cl, Br, CN, OH, linear or branched C1-C12 alkyls,
CF3, -OR6, -OPhenyl, -SR6, -SPhenyl, -SO2Phenyl, -COOR6,

-O- (CH2-CH = CH2), -O (CH2H2-O) mH, -O (C3H60) mH, m being between 1 and 100,

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- Rl représente un radical -CONH2, -CONHR6, -CON(R6)2, -P(O)(OR6)2 ou pyridyle-2 :
Ar2 R15
O # formule (V) dans laquelle : - Ar2 a la même signification que Ar1 de la formule (IV) dans le cas où n = 1, - R15 représente un radical choisi parmi le groupe constitué d'un radical Ar2, un radical alkyle linéaire ou ramifié en C1-C12, un radical cycloalkyle en C6-C12 et un radical cycloalkyle formant un cycle en C6-C12 avec le carbone de la cétone ou un carbone du radical Ar2, ces radicaux pouvant être substitués par un ou plusieurs substituants choisis dans le groupe constitué de -F, -Cl, -Br, -CN, -OH, -CF3,, -OR6, -SR6, -COOR6, les radicaux alkyles when n = 2, Ar1 represents a C6-C12 arylene radical or a phenylene-T-phenylene radical, where T represents -O-, -S-, -SO2- or -CH2-, X represents a group - OR or -OSiR8 (R9) 2 or form, with R4, a group - O-CH (R10) -, - R4 represents a linear or branched C1-C8 alkyl radical unsubstituted or bearing an -OH group, OR6, C2-C8 acyloxy, -CF3, or-CN, a C3 or C4 alkenyl radical, a C6-C18 aryl radical, a C7-C9 phenylalkyl radical, - R5 has one of the meanings given for R4 or represents a radical -
CH 2 CH 2 R 11, or together with R 4 form a C 2 -C 8 alkylene radical or a C 3 -C 9 oxa-alkylene or aza-alkylene radical; R 6 represents a lower alkyl radical containing from 1 to 12 carbon atoms; R 7 represents a hydrogen atom, a C1-C12 alkyl radical, a C2-C6 alkyl radical bearing an OH-group, -OR6 or CN, an alkenyl radical containing
C3-C6, a cyclohexyl or benzyl radical, a phenyl radical optionally substituted with a chlorine atom or a linear or branched C1-alkyl radical;
C12, or a tetrahydropyranyl-2 radical, - R8 and R9 are identical or different and each represents a C1-C4 alkyl radical or a phenyl radical, - R10 represents a hydrogen atom, a C1-C8 alkyl radical or a phenyl radical,

R1 represents a radical -CONH2, -CONHR6, -CON (R6) 2, -P (O) (OR6) 2 or pyridyl-2:
Ar2 R15
O # formula (V) in which: - Ar2 has the same meaning as Ar1 of formula (IV) in the case where n = 1, - R15 represents a radical chosen from the group consisting of a radical Ar2, an alkyl radical linear or branched C1-C12, a C6-C12 cycloalkyl radical and a cycloalkyl radical forming a C6-C12 ring with the carbon of the ketone or a carbon of the radical Ar2, these radicals being able to be substituted by one or more substituents chosen in the group consisting of -F, -Cl, -Br, -CN, -OH, -CF3 ,, -OR6, -SR6, -COOR6, the alkyl radicals

<Desc / Clms Page number 17>

# formule (VII) dans laquelle : - R5, identiques ou différents, ont les mêmes significations que dans la formule (III), - Y, identiques ou différents, représentent X et/ou R4, - Z représente : . une liaison directe, . un radical divalent alkylène en C1-C6, ou un radical phénylène, diphénylène ou phénylène-T-phénylène (T : alkyle linéaire ou ramifié en C1-C12), ou encore forme, avec les deux substituants R5 et les deux atomes de carbone porteurs de ces substituants, un noyau de cyclopentane ou de cyclohexane,

un groupe divalent -O-R12-O-, -O-SiR8R9-O-SiR8R9-0-, ou -0-SiR8R9-0-, - R12 représente un radical alkylène en C2-Cg, alcénylène en C4-C6 ou xylylène, linear or branched C 1 -C 12 optionally bearing an OH, -OR 6 and / or CN group, and linear or branched C 1 -C 8 alkenyl radicals; R16 # Ar3-P-R16 # # # formula (VI) where: - Ar3 has the same meaning as Arl of formula (IV) in the case where n = 1, - R16, identical or different, represents a radical chosen from the group consisting of a radical Ar3, a radical - (C = O) -Ar3, a linear or branched C1-C12 alkyl radical, a C6-C12 cycloalkyl radical, these radicals being able to be substituted by one or more substituents selected from the group consisting of -F, -Cl, -Br, -CN, -OH, -CF3, -OR6, -SR6, -COOR6, linear or branched C1-C12 alkyl radicals optionally bearing a OH-group, -OR6 and / or-CN, and linear or branched C1-C8 alkenyl radicals;

formula (VII) in which: R5, which are identical or different, have the same meanings as in formula (III); Y, which are identical or different, represent X and / or R4; Z represents: a direct connection,. a divalent radical C1-C6 alkylene, or a radical phenylene, diphenylene or phenylene-T-phenylene (T: linear or branched C1-C12 alkyl), or form with the two substituents R5 and the two carbon atoms of these substituents, a cyclopentane or cyclohexane ring,

a divalent group -O-R12-O-, -O-SiR8R9-O-SiR8R9-O-, or -O-SiR8R9-O-, -R12 represents a C2-C8alkylene, C4-C6alkenylene or xylylene radical; ,

<Desc / Clms Page number 18>

- or else the entity:
YY @ Z ####
R5 R5 corresponds to -OO- - and Ar4 has the same meaning as Ar1 of formula (IV) in the case where n = 1.

- m = 0 à 8, - R17, identique (s) ou différent(s) substituants sur le (s) aromatique (s), un radical alkyle linéaire ou ramifié en C1-C12, un radical cycloalkyle en C6-C12, un radical Ar1, un atome d'halogène, un groupement-OH, -CN, -N02, -COOR6, -CHO, O-phényle, -CF3, -SR6, -Sphényle , -S02 phényle ,

O-alcényle ou -SiR63 # famille des xanthènes de formule (IX) :

n = 0 à 8 # famille des xanthones de formule (X):

# family of thioxanthones of formula (VIII):

- m = 0 to 8, - R17, identical (s) or different (s) substituents on the aromatic (s), a linear or branched C 1 -C 12 alkyl radical, a C 6 -C 12 cycloalkyl radical, a radical Ar 1, a halogen atom, a group -OH, -CN, -NO 2, -COOR 6, -CHO, O-phenyl, -CF 3, -SR 6, -Sphenyl, -SO 2 phenyl,

O-alkenyl or -SiR63 # family of xanthenes of formula (IX):

n = 0 to 8 # family of xanthones of formula (X):

<Desc / Clms Page number 19>

q = 0 à 8 # famille de l'anthracène de formule (XII) :

r = 0 à 10 # famille du phénanthrène de formule (XIII) :

s = 0 à 10 # famille du pyrène de formule (XIV) :

t = 0 à 10 # famille du fluorène de formule (XV) :

p = 0 to 8 # family of naphthalene of formula (XI):

q = 0 to 8 # family of anthracene of formula (XII):

r = 0 to 10 # phenanthrene family of formula (XIII):

s = 0 to 10 # pyrene family of formula (XIV):

t = 0 to 10 # fluorene family of formula (XV):

<Desc / Clms Page number 20>

v=OàlO # famille du chrysène de formule (XVII) :

w = 0 à 12 # famille de la fluorène de formule (XVIII) :

avec x = 0 à 8, par exemple 2,7 dinitro 9-fluorénone, # famille de la chromone de formule (XIX) :

avec y = 0 à6 u = 0 to 9 # family of fluoranthene of formula (XVI):

v = 0 to 0 # chrysene family of formula (XVII):

w = 0 to 12 # fluorene family of formula (XVIII):

with x = 0 to 8, for example 2.7 dinitro 9-fluorenone, # family of the chromone of formula (XIX):

with y = 0 to 6

<Desc / Clms Page number 21>

avec z= 0 à 5 avec z= 0 à 6 # famille de l'érythrosine de formule (XXI) :

avec z = 0 à 5 avec z= 0 à 6 # famille des biscoumarines de formule (XXII) :

# eosin family of formula (XX):

with z = 0 to 5 with z = 0 to 6 # family of erythrosine of formula (XXI):

with z = 0 to 5 with z = 0 to 6 # family of biscoumarins of formula (XXII):

1x 17 - R, identical or different, has the same meaning as R or represents a group -NR 2 'for example 3,3'carbonylbis (7-diethylaminocoumarin) 3,3'-carbonylbis- (7-methoxycoquarin) ).

 Other sensitizers are usable. In particular, it is possible to use the photosensitizers described in documents US Pat. No. 4,939,069; 4,278,751; US 4,147,552.

<Desc / Clms Page number 22>

 In the context of the present invention, the photosensitizers have a residual U.V light absorption of between 200 and 500 nm, preferably 400 to 500 nm for dental prosthesis preparations. For the dental restoration, a photosensitizer having a residual absorption of U.V light beyond 400 nm will be preferred.

# 2-isopropylthioxanthone ; # l-chloro-4-propoxythioxanthone ; # 4-isopropylthioxanthone ; #

# et leurs mélanges. According to a preferred variant, the photosensitizers will be chosen from those of families (IV), (VI), (VII) and (VIII). By way of examples, mention may be made of the following phosensitizers: # 4,4'-dimethoxybenzoin;# 2-4 diethyl thioxanthone; # 2-ethylanthraquinone; # 2-methylanthraquinone; # 1,8-dihydroxyanthraquinone; # dibenzoylperoxide; # 2,2-dimethoxy-2-phenylacetophenone; benzoin; 2-hydroxy-2-methylpropiophenone; benzaldehyde; 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-methylpropyl) ketone; # benzoylacetone;

# 2-isopropylthioxanthone; # 1-chloro-4-propoxythioxanthone; # 4-isopropylthioxanthone; #

# and their mixtures.

<Desc / Clms Page number 23>

 In this case of treatment of or silica fillers in particular silica with this type of polymer, the material obtained after crosslinking has a significantly improved mechanical strength, modulus of elasticity, and compressive strength.

 In addition to the reinforcing fillers, pigments can be used to tint the dental composition according to the intended use and ethnic groups.

 For example, red pigments are used in the presence of microfibers for dental compositions used for the preparation of dental prostheses to simulate blood vessels.

 Pigments based on metal oxides (iron oxides and / or titanium and / or aluminum and / or zirconium, etc.) are also used for the dental compositions used for the preparation of restoration material, in order to obtain a material reticulated ivory color.

 Other additives may be incorporated into the dental compositions according to the invention. For example, biocides, stabilizers, flavoring agents, plasticizers and adhesion promoters.

 Among the additives that can be envisaged, cross-linkable and / or polymerizable co-reactants of organic type will advantageously be used. These co-reactants are liquid at room temperature or hot melt at a temperature below 100 ° C., and each coreactant comprises at least two reactive functional groups such as oxetane-alkoxy, oxetanehydroxy, oxetane-alkoxysilyl, carboxyoxetane, oxetane-oxetane, alkenylether-hydroxy alkenyl ether-alkoxysilyl, epoxy-alkoxy, epoxy-alkoxysilyl, dioxolane-dioxolane-alcohol, etc.

 The dental compositions according to the invention can be used for many dental applications, and in particular in the field of dental prostheses, in the field of dental restoration and in the field of temporary teeth.

 The dental composition according to the invention is preferably in the form of a single product containing the various components ("monocomponent") which facilitates its implementation, particularly in the field of dental prostheses. Optionally, the stability of this product can be provided by organic derivatives with amine functions according to the teaching of the document WO 98/07798.

<Desc / Clms Page number 24>

 In the field of dental prostheses, the product in the form "monocomponent" can be deposited using a syringe directly on the plaster model or in a key. Then, it is polymerized (polymerization possible successive layers) using a UV lamp (visible light spectrum 200 - 500 nm).

 In general, it is possible to achieve in 10 to 15 minutes a durable and aesthetic dental prosthesis.

 It should be noted that the products obtained from the dental composition according to the invention are non-porous. Thus, after a possible polishing with a felt brush, for example, the surface of the dental prostheses obtained is smooth and shiny and therefore does not require the use of varnish.

 The applications in the field of dental prostheses are essentially those of the adjunct prosthesis, which can be divided into two types: - total prosthesis in case of patient completely edentulous - partial prosthesis due to the absence of several teeth resulting in either a temporary prosthesis, a skeletal device.

 In the field of dental restoration, the dental composition according to the invention can be used as a material for sealing the anterior and posterior teeth in different shades (for example, "VITA" shades), quick and easy to implement. .

 Since the dental composition is non-toxic and polymerizable in thick layers, it is not essential to polymerize the material in successive layers. In general, a single injection of the dental composition is sufficient.

 Preparations for dental prostheses and restoration materials are performed according to the usual techniques of the art.

 In the case of application of the dental composition to a tooth, either the tooth may be pretreated with a primer or the dental composition may be prepared in admixture with a primer prior to use.

 The following Examples and Tests are given for illustrative purposes. They allow in particular to better understand the invention and to highlight some of its advantages and to illustrate some of its variants.

<Desc / Clms Page number 25>

Description of the single FIGURE: The attached single figure shows the viscosity evolution curves in Pa.s-1 as a function of the duration in days of storage.

Il est obtenu à partir de 4-vinylcyclohexène-époxyde (VCMX) commercialisé par la société Union Carbide # (systématiquement distillé avant utilisation) et de tétraméthylhydrogénodisiloxane (M'2) utilisé est fabriqué par Rhodia Silicones, lui aussi distillé avant utilisation, en présence de catalyseur Pt sur Noir 2S humide est commercialisé par la société ALDRICH sous la référence 33,015-9. Le taux de Platine est de 1,2% en poids. Le taux d'humidité est de 50% en poids. The legend of this figure is the following: --- # --- control 1 --- # --- control 2 - # - formulation 1 according to the invention (example 2.2) --------- formulation 2 according to the invention (example 2.3) - # ---- formulation 3 according to the invention (example 2.4) EXAMPLES AND TESTS:
The silicone (1) with epoxy functionality used in the examples is (A):

It is obtained from 4-vinylcyclohexene-epoxide (VCMX) sold by the company Union Carbide # (systematically distilled before use) and tetramethylhydrogenodisiloxane (M'2) used is manufactured by Rhodia Silicones, also distilled before use, in the presence Pt catalyst on Wet Black 2S is marketed by the company ALDRICH under the reference 33,015-9. The Platinum content is 1.2% by weight. The moisture content is 50% by weight.

The functionalization aid used is sodium hydrogencarbonate (NaHCO3).

The common operating procedure is as follows: In a 100 ml reactor, 66 g (531 mmol = 1.05 eq) of VCMX are charged, the amount of platinum required in the form of the catalyst Pt on black 2S, and optionally the water and sodium hydrogencarbonate. The reaction mixture is then heated to 90 ° C. 34 g (506 mmol = 1 eq) of M'2 are then run dropwise over 5 hours into the reactor. During the synthesis, the progress of the reaction is determined by the disappearance of the units = SiH and the possible disappearance of the epoxy functions is followed by potentiometric titration. When all the units = SiH have reacted, the reaction mixture is filtered and then devolatilized for 7 hours under vacuum at high temperature in the presence or absence of sodium hydrogen carbonate. The viscosity, which is directly correlated with the loss of epoxide functions, is measured before and after devolatilization.

<Desc / Clms Page number 26>

La charge (2) utilisée est un quartz commercialisé par la société Schott sous la référence

G018-066 de granulométries 0,7 jum ; l,5m ; 3,5/-lm ;ou 5pm. The product obtained contains between 85 and 99% of silicone (1) of Formula (A) supra and RNCAS 18724.32.-8 The photoinitiator (3) onium borate used to trigger the polymerization of the epoxy groups under UV is described in US Pat. patent application EP 0 562 897.

The filler (2) used is a quartz sold by Schott under the reference

G018-066 of particle size 0.7 μm; 1.5m; 3.5 / -m or 5pm.

These quartz are analyzed by infra red diffuse reflection and recorded three zones of silanol bands (free silanols, associated silanols 1 and associated silanols 2) between 3300-4000cm-1. The concentration of active silanol sites increases with the available surface area and increases with decreasing particle size.

EXAMPLE 1 1.1. Preparation of a Control Formulation 1 Without Dispersant In a centrifugal mixer of the Hauschild brand, 25 g of quartz (SiO2> 99%) with a particle size of 5 m marketed by Schott, 3 g of ytterbium trifluoride and 10 g of resin are loaded. siloxane having a monomer content (A)> 90% obtained by hydrosilylation of VCMX according to a manufacturing method as described above.

The mixture is shaken 16 s with the centrifugal mixer then 1.25 g of photoinitiator system containing 30% P1 photoinitiator and 0.23% CPTX chloropropoxythioxanthone photosensitizer marketed by Lambson, all in solution in the resin (A) without solvent. 16s are stirred with the centrifugal mixer. 5 g of combustion silica (SiO2> 99%) are then added, followed by stirring for 16 seconds. 5.75 g grams of combustion silica are added and the mixture is stirred for 16 seconds.

Combustion silica is a silica sold by Degussa under the name OX-50, which has a specific surface area of 40 m 2 / g.

The viscosity evolution curve is given in the single appended figure.

The preparation is gelled after 1 month, stored at 20 C.

<Desc / Clms Page number 27>

1. Preparation of a control formulation 2 without dispersant 25 g of quartz (SiO2> 99%) with a particle size of 3 m sold by Schott, 3 g of ytterbium trifluoride, are charged into a Hauschild centrifugal mixer. g of siloxane resin having a monomer content (A)> 90% obtained by hydrosilylation of VCMX, as described above.

The centrifuge is stirred for 16 seconds and then 1.25 g of photoinitiator system in (A) containing 30% of photoinitiator P1 and 0.23% of photosensitizer (4) based on chloropropoxy thioxanthone CPTX sold by Lambson are added. 16s are stirred with the centrifugal mixer. 5 g of combustion silica (SiO2> 99%) are then added, followed by stirring for 16 seconds. 5.75 g of fumed silica are added, followed by stirring for 16 seconds. Combustion silica is a silica sold by Degussa under the name OX-50 and with a specific surface area of 40 m 2 / g.

The viscosity evolution curve is given in the single appended figure.

The preparation is gelled after 48 hours, stored at 20 C.

EXAMPLE 2 1. Preparation According to the Invention
The byk164 dispersant (8 g) is dissolved in the resin (A) in a proportion of 4% and then devolatilized so as to remove the butyl acetate contained in the dispersant by heating under vacuum of 10 mmHg at 60 ° C. for 3 minutes. hours in a rotary evaporator.

The concentration of active ingredient is 2.4%.

2. Preparation of a Formulation 1 with Dispersant In a centrifugal mixer of the brand Hauschild #, 25 g of quartz (SiO2> 99%) with a particle size of 5 m marketed by Schott, 3 g of ytterbium trifluoride are charged, 1.25 g of solution of devolatilized byk # 164 dispersant in the resin (A) as previously described, shaken 16s with the centrifugal mixer. 9 g of resin (A) are added.

The mixture is stirred for 16 seconds with the centrifugal mixer, then 1.25 g of photoinitiator system in (A) containing 30% P1 photoinitiator and 0.23% CPTX photosensitizer are added. 16s are stirred with the centrifugal mixer. 5 g of combustion silica (SiO2> 99%) are then added, followed by stirring for 16 seconds. 5.5 g of combustion silica are added, followed by stirring for 16 seconds.

We follow the evolution of the viscosity over time.

<Desc / Clms Page number 28>

The preparation does not gel after 1 month, stored at 20 C.

The viscosity evolution curve is given in the single appended figure.

2. Preparation of a Formulation 2 with Dispersant In a centrifugal mixer of the brand Hauschild, 25 g of quartz (SiO2> 99%) with a particle size of 3 m marketed by Schott, 3 g of ytterbium trifluoride, 1 g. 25 g of devolatilized by-16 dispersant solution in resin (A) were stirred with the centrifugal mixer. 9 g of resin (A) are added.

The mixture is stirred for 16 seconds with the centrifugal mixer and then 1.25 g of photoinitiator system in (A) containing 30% P1 photoinitiator and 0.23% CPTX photosensitizer are added. The mixture is stirred for 16 seconds with the centrifugal mixer. 5 g of combustion silica (SiO2> 99%) are then added, followed by stirring for 16 seconds. 5.5 g of combustion silica are added, followed by stirring for 16 seconds.

We follow the evolution of the viscosity over time.

The preparation does not gel after 1 month, stored at 20 C.

The viscosity evolution curve is given in the single appended figure.

2. 4. Preparation of a formulation 3 with dispersant In a centrifugal mixer of the Hauschild brand, 25 g of quartz (SiO2> 99%) with a particle size of 1.5 m marketed by Schott, 3 g of ytterbium trifluoride are charged. 1.25 g of devolatilized byk dispersant solution # 164 in resin (A) were stirred 16s with the centrifugal mixer. 9 g of resin (A) are added.

16s are stirred with the centrifugal mixer, then 1.25 g of photoinitiator system in (A) containing 30% of photoinitiator P1 and 0.23% of photosensitizer based on chloropropoxythioxanthone CPTX are added. 16s are stirred with the centrifugal mixer.

5 g of combustion silica (SiO2> 99%) are then added, followed by stirring for 16 seconds.

5.5 g grams of combustion silica are added, followed by stirring for 16 seconds.

We follow the evolution of the viscosity over time.

The preparation does not gel after 1 month, stored at 20 C.

The viscosity evolution curve is given in the single appended figure.

Viscosity is measured by placing the composite paste in the plane / plane gap of a rheometer and with a shear rate of 4s-1. The composition takes on a Newtonian character with the addition of dispersant. The viscosity does not evolve even under a high shear gradient.

<Desc / Clms Page number 29>

EXAMPLE 3 Photopolymerization of Dental Restoration Formulations 1, 2 and 3 (≈ 2, 2, 3, 2, 4, 4 supra) The formulations crosslink over a thickness of 3 mm in 40 seconds of irradiation with an Optilux Demetron lamp. The Vickers hardness measured after photocrosslinking is 50 for each of the three formulations. Flexural modulus and flexural strength measured according to IS04049 are respectively 5 GPa and 80 MPa.

EXAMPLE 4 1. Preparation of a Formulation with Dispersing Phosphate (830 ppm): Against Example 4 [0103] 125 g of monomer (A) and 15 g are charged into a three-blast mixer with slow stirring (<10 rpm). solution of Solsperse 36000 sold by the company AVECM at 4% in the monomer A. Mix for 5 minutes. 18 g of photoinitiator system containing 30% of photoinitiator P1 and 0.23% of photosensitizer based on chloropropoxythioxanthone CPTX are added. Mix for 5 minutes at room temperature.

The quartz (SiO2> 99%) of 3.5 m particle size sold by Schott is added, ie 378.5 g and 45 g of ytterbium trifluoride. It is mixed for about one hour at room temperature until a homogeneous fluid viscous mixture is obtained. 137 g of OX50 combustion silica are added little by little for 2 hours by successive additions of 15 g. The mixture is kept in 5 g cartridges after being discharged in an air-conditioned room at 25 ° C.

4. Preparation of a Formulation with Dispersant without Phosphate (830 ppm): Example 4 The same operation as above is repeated, substituting the 15 g of solution of Solsperse 360000 with 15 g of Disperbyk 164 0 4%, with a subscript. amine content of 20 mg KOH / g dispersant.

It is then observed how many months the products stored in cartridge gel.

The product stored with phosphate dispersant gelled in 3 months at 25 ° C. After one year, the product with dispersant with amine number <100 mg of potassium hydroxide / g of dispersant, is still usable and not gelled. It crosses in less than 1 minute to 3 mm with a flexural modulus close to 10 GPa at the flexion of 80 MPa.

Claims (16)

1. Dental composition comprising: (1) at least one cationically reactive compound and under activation preferably actinic; (2) at least one dental filler present in a proportion of at least 10% by weight relative to the total weight of the composition; (3) at least one dispersant based on at least one organic polymer or copolymer chosen from those whose amine number is less than or equal to 100 mg of potassium hydroxide per gram of dispersant; (4) at least one cationic photoinitiator; (5) and optionally at least one photosensitizer.  2. Composition according to claim 1, characterized in that the acid number is less than 200 mg of potash per gram of dispersant.  3. Composition according to claim 1 characterized in that the dental load (2) is present in a proportion of 10 to 85% by weight. The dental composition according to claim 1 or 2, characterized in that the dispersant (3) is selected from the group consisting of: polyurethane / acrylate copolymers; optionally salified with an alkylammonium.  5. Dental composition according to any one of claims 1 to 4, characterized in that the dispersant (3) is present at 50 ppm to 1%, preferably 100 to 5000 ppm.  6. Dental composition according to any one of claims 1 to 5, characterized in that the cationically reactive compound (1) is selected from the group of monomers and / or (co) polymers comprising: epoxies, vinyls ethers, oxetanes, spiroorthocarbonates, spiroorthoesters and their combinations.  7. Dental composition according to any one of claims 1 to 6, characterized in that the cationically reactive compound (1) consists of at least one oligomer or crosslinkable silicone polymer and / or polymerizable, liquid at room temperature or hot melt at a temperature below 100 C, and comprising: <Desc / Clms Page number 31>  # at least one unit of formula (FS): in which: - a = 0, 1 or 2, - R, identical or different, represents an alkyl, cycloalkyl, aryl, vinyl, hydrogen, alkoxy radical, preferably a lower alkyl radical; C1-C6, - Z, which may be identical or different, is an organic substituent comprising at least one epoxy reactive functional group, and / or alkenyl ether and / or oxetane and / or dioxolane and / or carbonate functional groups, # and at least two silicon atoms.  8. Dental composition according to claim 7, characterized in that Z is an organic substituent Z1 comprising at least one epoxy reactive functional group, and / or dioxolane, and preferably at least one epoxy reactive functional group.  9. A composition according to claim 6 or 7, characterized in that the oligomer or polymer (1) further comprises other reactive functions Z such as the reactive functions Z2 alkenyl ether, oxetane and / or carbonate.  10. Composition according to claim 6 or 7, characterized in that the reactive function (s) of Zl are chosen from the following radicals: <Desc / Clms Page number 32>  [(R 1) n - A - (R 2) m] + (I) in which: # A represents an element from groups 15 to 17 such as for example: I, S, Se, P or N, # R1 represents a carbocyclic or C6-C20 heterocyclic aryl radical, said heterocyclic radical being able to contain, as heteroelements, nitrogen or sulfur, # R2 represents R1 or a linear or branched C1-C30 alkyl or alkenyl radical; said radicals R1 and R2 being optionally substituted with a C1-C25alkoxy, C1-C25alkyl, nitro, chloro, bromo, cyano, carboxy, ester or mercapto group, # n is an integer ranging from 1 to v + 1; where v is the valence of element A, # m is an integer from 0 to v - 1 with n + m = v + 1, (2) oxoisothiochromanium salts; (3) organometallic salts of formula (III): (L1L2L3M) + q in which: # M represents a group 4 to 10 metal, especially iron, manganese, chromium, cobalt, # L1 represents 1 ligand bound to the metal M by electrons #, ligand chosen from

 the β-alkyl, η5-cyclopendadienyl and 117-cycloheptratrienyl ligands and the 116-aromatic compounds selected from the optionally substituted 116-benzene ligands and the compounds having 2 to 4 fused rings, each ring being capable of contributing to the valence layer of the metal M with 3 to 8 electrons #, # L2 represents a ligand bound to the metal M by electrons #, chosen ligand

 among the 117-cycloheptatrienyl ligands and the 116-aromatic compounds selected from the optionally substituted # 6- benzene ligands and the <Desc / Clms Page number 33>  # whose borate anionic entity has the formula [BXa Rb] - in which: a and b are integers ranging from 0 to 3 and for b from 1 to 4 with a + b = 4; X symbols represent: * a halogen atom (chlorine, fluorine) with a = 0 to 3, * an OH function with a = 0 to 2, - the symbols R are identical or different and represent: # a phenyl radical substituted by at least one electron-withdrawing group 15 such as, for example, OCF 3, CF 3, NO 2, CN, and / or with at least 2 halogen atoms (especially fluorine), and this when the cationic entity is an onium of an element of groups 15 to 17, # a phenyl radical substituted with at least one element or an electron-withdrawing group, in particular halogen atom (especially fluorine), CF 3, OCF 3, NO 2, CN, and this when the cationic entity is an organometallic complex of an element of groups 4 to 10, # an aryl radical containing at least two aromatic rings such as, for example, biphenyl, naphthyl, optionally substituted by at least one element or an electron-withdrawing group, especially a halogen atom including fluorine in particular, OCF3, CF3, NO2, CN, whatever the cationic entity.  12. Composition according to claim 11, characterized in that the photoinitiator is chosen from the group consisting of:

 [(C8H17) --- I -) + [B (C6F5) 4] -; [C12H25 - I- + [B (C6F5) 4] -; [(C8H17 -) 2I + [B (C6F5) 4] -; [(C8H17) --- I -) + [B (C6F5) 4] -; [D) 2S- (D-O-C8H71 +, [B (C6H4CF3) 4] -; [(C12H25-) 2I + [B (C6F5) 4] -; [CH3- <DI- <D-CH (CH3h] +, [B (C6F5) 4] - (115 - cyclopentadienyl) (116 - toluene) Fe +, [B (C6F5) 4] - (115 - cyclopentadienyl) (116 - methyl - 1 - naphthalene) Fe +, [B (C6F5) 4; <Desc / Clms Page number 34> 13. Dental composition according to any one of claims 1 to 12, characterized in that it comprises an aromatic hydrocarbon-based photosensitizer (5) with one or more aromatic nuclei substituted or unsubstituted, having a residual absorption of light of between 200 and 500 nm. 10 14. Composition according to Claim 13, characterized in that the photosensitizer is chosen from the group consisting of: # 4,4'-dimethoxybenzoin; # 2-4 diethyl thioxanthone; # 2-ethylanthraquinone; # 2-methylanthraquinone; # 1,8-dihydroxyanthraquinone; # dibenzoylperoxide; # 2,2-dimethoxy-2-phenylacetophenone; benzoin; 2-hydroxy-2-methylpropiophenone; benzaldehyde; 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-methylpropyl) ketone;

 ## EQU1 ## <Desc / Clms Page number 35>  # and their mixtures. 5 15. Dental composition according to any one of claims 1 to 14, characterized in that the oligomer and / or silicone polymer (1) is constituted by at least one silicone of average formula: <Desc / Clms Page number 36> 0 CH2CH-CH2 ## CHCH CH

 CH, CH, CH, H 2 C CH3 - Si-CH3 O # CH3 - Si-CH3 CH2CH2CH2 # O CH2CH-CH2 # # O <Desc / Clms Page number 37> <Desc / Clms Page number 38> 16. Use of a dental composition according to any one of claims 1 to 15 for the production of dental prostheses.  5 17. Use of a dental composition according to any one of claims 1 to 15 for the dental restoration.  18. Dental prosthesis obtainable from a composition according to any one of claims 1 to 15.  19. Dental restoration material obtainable from a composition according to any one of claims 1 to 15.