CN120456887A

CN120456887A - Surface-treated filler, dental composition containing such filler, method for producing the same and use thereof

Info

Publication number: CN120456887A
Application number: CN202380082793.3A
Authority: CN
Inventors: 蒂莫西·邓巴; 卡斯滕·德德; 布雷德利·克莱格; 格利格里·索伦森; 托马斯·克伦; 查得·阿玛巴
Original assignee: Shuwanuo Intellectual Property Co
Current assignee: Shuwanuo Intellectual Property Co
Priority date: 2022-12-06
Filing date: 2023-11-16
Publication date: 2025-08-08
Also published as: EP4629958A1; WO2024121658A1

Abstract

The present invention relates to a dental composition comprising a curable component and a surface treated filler comprising filler particles the surface of which has been treated with a surface treating agent characterized by comprising at least one (meth) acrylate moiety, comprising at least one hydrolyzable silane moiety, comprising only one urethane moiety, comprising a linear alkylene moiety AM1 connecting the at least one (meth) acrylate moiety to the urethane moiety, comprising a linear alkylene moiety AM2 connecting the at least one hydrolyzable silane moiety to the urethane moiety, the linear alkylene moiety AM1 comprising more carbon atoms than the linear alkylene moiety AM 2. The invention also relates to a method of producing such a dental composition, to the use of the dental composition in a method of restoring a dental tooth, and to a kit of parts comprising the dental composition.

Description

Surface-treated filler, dental composition containing such filler, method for producing the same and use thereof

Technical Field

The present invention relates to a surface treated filler and a dental composition containing such a filler. A method for producing such a filler and the use of a dental composition for restoring teeth are also described. The surface treated filler is particularly useful for producing flowable or injectable dental compositions having low viscosity at low shear rates.

Background

Polymerizable dental compositions for repairing defective teeth are widely known.

Dental compositions typically comprise a resin matrix containing a polymerizable component, an initiator system suitable for curing the polymerizable component, and a filler system.

In order to obtain sufficient mechanical properties after hardening, it is often desirable to provide a composition with a high filler loading.

However, filler particles typically have a relatively polar surface, while the polymerizable component is relatively non-polar. Thus, incorporating large amounts of polar fillers into a fairly nonpolar resin matrix can become challenging.

To solve this problem, the filler particles are typically surface treated with a silane component to make the filler particles more compatible with the resin matrix.

However, as the filler loading increases, the viscosity or consistency of the polymerizable dental composition generally increases, which makes the dental composition more difficult to handle, particularly during the step of extruding the dental composition from the packaging apparatus.

However, for certain applications practitioners prefer dental compositions having a rather low viscosity and easy flow, yet which should still exhibit sufficient mechanical properties after curing.

In the patent literature, various attempts are described in this respect.

US 10,441,512 B2 (Tanaka et al) describes a dental flowable composite composition comprising a polymerizable monomer, inorganic particles (a) and inorganic particles (B), wherein the inorganic particles (a) are surface treated with a compound represented by the general formula (1), and the inorganic particles (B), wherein at least one of a group represented by the general formula (a) and a group represented by the general formula (B) is present on the surface of the inorganic particles (B). In the examples, as the surface treatment agent, mainly 3-methacryloxypropyl trimethoxysilane and 8-methacryloxyoctyl trimethoxysilane were used. The composite composition is said to have good polishability, abrasion resistance, formability, handleability and flexural strength.

US 10,975,229 B2 (Fuchigami et al) relates to a silane coupling agent and a medical and/or dental curable composition comprising the same. The silane coupling agent is said to impart high affinity to the free radically polymerizable monomer, thereby imparting high mechanical strength, flexibility and durability when used in medical and/or dental curable compositions and inorganic fillers surface-treated with the silane coupling agent. The silane coupling agent contains a repeating unit such as a urethane bond and polyethylene glycol (ether bond) at a specific position.

US 10,561,584 B2 (Kojima et al) describes a dental adhesive comprising a polymerizable monomer, first and second and third inorganic particles, respectively, which have been surface treated with a chemical compound. In the examples, as the surface treatment agent, mainly 3-methacryloxypropyl trimethoxysilane and 8-methacryloxyoctyl trimethoxysilane were used.

U.S. Pat. No. 10,918,578 B2 (Wang et al) describes a dental curable composition comprising a polymerizable monomer, inorganic particles (A1) and/or inorganic particles (A2), inorganic particles (B). The inorganic particles (A1) are particles surface-treated with a compound represented by the general formula (1). The inorganic particles (A2) are particles surface-treated with a compound represented by the general formula (2). The inorganic particles (B) are particles having a group represented by the general formula (a) at the surface, particles having a group represented by the general formula (B) at the surface, and/or particles surface-treated with a compound represented by the general formula (3).

US 11,246,808 B2 (Craig et al) describes a dental composition comprising a polymerizable resin comprising one or more ethylenically unsaturated monomers or oligomers and nanoparticles. The nanoparticles have a refractive index of at least 1.600 and an average discrete or aggregate particle size of no greater than 100 nm. The dental composition further comprises an inorganic metal oxide filler having a discrete or aggregate average particle size of at least 200 nm.

US 9,050,252 B2 (Craig et al) describes a method of surface treating inorganic oxide particles, a hardenable (e.g., dental) composition comprising a polymerizable resin composition and surface treated particles, and surface treated (e.g., nanoclustered) inorganic oxide particles and a silane surface treatment compound. In one embodiment, the method includes forming a surface treatment compound by reacting a first functional group of a (meth) acrylate monomer having a molecular weight of at least 350g/mol with a second functional group of a silane compound, wherein the first functional group and the second functional group react to form a covalent bond, and combining the surface treatment compound with inorganic oxide particles.

Various silane treatments are also described in JP 6,904,646 B2, JP 6220723 B2, JP 6,173,254 and JP 2021/155395A.

Disclosure of Invention

None of the options outlined in the prior art fully meet the needs of practitioners.

There remains a need for an easily handled curable dental composition, in particular a dental composition that can be easily applied to the tooth surface to be repaired.

In particular, there is a need for dental compositions with small structures, which are typically accompanied by low viscosity at low shear rates.

Furthermore, the dental composition should still have sufficient mechanical properties after curing.

The invention described herein and in the claims solves one or more of the above objects.

According to one aspect, the present invention relates to a surface-treated filler comprising filler particles whose surface has been treated with a surface treatment agent characterized by the following features:

comprising at least one (meth) acrylate moiety,

Comprising at least one hydrolyzable silane moiety,

Comprising only one urethane moiety,

Comprising a linear alkylene moiety AM1 linking the at least one (meth) acrylate moiety to the urethane moiety,

Comprising a linear alkylene moiety AM2 linking the at least one hydrolyzable silane moiety to the urethane moiety,

The linear alkylene moiety AM1 contains more carbon atoms than the linear alkylene moiety AM 2.

Another aspect of the invention relates to a dental composition comprising a curable component and a surface treated filler as described herein, in particular in an amount of 40 to 80 wt% relative to the weight of the dental composition.

Another aspect of the invention relates to a method for producing a surface treated filler as described herein, comprising the steps of

Optionally combining filler particles with a surface treatment agent using a dispersion,

Reacting the surface treatment agent with the filler particles,

The optional dispersion liquid is removed and the solution is mixed,

Optionally drying and sieving the surface-treated filler particles.

Yet another aspect of the invention relates to a dental composition for use in a method of repairing a tooth in the oral cavity of a mammal, the dental composition as described herein, the method comprising the steps of

Contacting the dental composition with the surface of the tooth to be repaired,

The dental composition is cured by application of radiation.

Furthermore, the present invention relates to the use of a surface treated filler for reducing the viscosity of a dental composition at low shear rates, the dental composition comprising a curable component and the filler in an amount of 40 to 80 wt% relative to the weight of the dental composition.

Additional embodiments relate to kits comprising the dental compositions described herein and, alone or in combination, dental adhesives, dental curing lights, and applicator instruments.

Unless defined differently, for purposes of this specification, the following terms shall have the given meanings:

by "one-part composition" is meant that all components of the composition are present together during storage and use. That is, the composition to be applied or used is not prepared by mixing different parts of the composition prior to use. In contrast to one-part compositions, those compositions are often referred to as two-part compositions (e.g., formulated as powder/liquid, liquid/liquid, or paste/paste compositions).

By "two-component composition" is meant that the components are provided as separate parts from each other as a kit or system prior to use. For use, the respective components or parts need to be mixed.

The term "compound" or "component" is a chemical substance having specific molecular characteristics or a chemical substance made from a mixture of such substances, such as a polymeric substance.

A "hardenable or polymerizable component" is any component that can be cured or set by radiation-induced polymerization in the presence of a photoinitiator. The hardenable component may contain only one, two, three or more polymerizable groups. Typical examples of polymerizable groups include unsaturated carbon groups such as vinyl groups present in, for example, (meth) acrylate groups.

As used herein, "(meth) acryl" is a shorthand term that refers to "acryl" and/or "methacryl". For example, "(meth) acryloyloxy" group is a shorthand term referring to an acryloyloxy group (i.e., CH ₂ =ch-C (O) -O-) and/or a methacryloyloxy group (i.e., CH ₂=C(CH₃) -C (O) -O-).

As used herein, "hardening" or "curing" a composition is used interchangeably and refers to polymerization and/or crosslinking reactions involving one or more materials contained in the composition, including, for example, photopolymerization reactions and chemical polymerization techniques (e.g., ionic reactions or chemical reactions that form radicals effective to polymerize ethylenically unsaturated compounds).

By "radiation curable" is meant that the component (or composition, as the case may be) is curable by application of radiation (preferably electromagnetic radiation having a wavelength in the visible spectrum) at ambient conditions and within a reasonable time frame, such as within about 60 seconds, 30 seconds, or 10 seconds.

"Paste" refers to a soft, viscous substance of solids (i.e., particles) dispersed in a liquid.

"Particle" means a solid substance having a geometrically determinable shape. The shape may be regular or irregular. The particles can generally be analyzed with respect to, for example, particle size and particle size distribution.

The particle size (d 50) of the powder can be obtained from the cumulative curve of the particle size distribution. Corresponding measurements can be made using a commercially available particle sizer (e.g., malvern Mastersizer a 2000). "D" means the diameter of the powder particles, and "50" means the volume percent of the particles. Sometimes, 50% is also denoted "0.5". For example, "(d 50) =1 μm" means that 50% of the particles have a size of 1 μm or less.

The term "primary particle size" refers to the size of the unassociated individual particles. X-ray diffraction (XRD) is commonly used to measure primary particle size using the techniques described herein.

"Nanosized filler" is a filler whose individual particles have a size in the nanometer range, for example an average particle diameter of less than 100 nm. Examples of such may be found in U.S. Pat. No. 6,899,948 (Zhang et al) and U.S. Pat. No. 6,572,693 (Wu et al).

The measurement of the nanoparticle size is preferably based on a TEM (transmission electron microscope) method whereby the population is analyzed to obtain an average particle size. The preferred method for measuring particle size can be described as follows:

Samples of approximately 80nm thickness were placed on 200 mesh copper grids with a carbon stabilized polymethylvinyl acetate substrate (SPI supply company-structural Probe division (SPI support-Structure Probe, inc., WEST CHESTER, PA) of west chester, pa). Transmission Electron Micrographs (TEMs) were taken at 200KV using JEOL 200CX (JEOL, ltd., akishima, japan) and sold by JEOL USA, inc. Population sizes of about 50-100 particles can be measured and the average diameter determined.

"Agglomeration" describes a weak association of particles that are held together, typically by charge or polarity, and can break down into smaller entities. The specific surface area of the agglomerate grains is substantially not different from the specific surface area of the primary grains constituting the agglomerate (see DIN 53206; 1972).

Agglomerated filler is commercially available, for example, from Degussa, cabot Corp (Cabot Corp), or Wacker (Wacker) under the product designations Aerosil ^™、CAB-O-SIL^™ and HDK ^™.

As used herein, "aggregated" describes a strong association of particles that are typically bound together by, for example, residual chemical treatment or partial sintering. The specific surface area of the agglomerate particles is generally smaller than the specific surface area of the primary particles constituting the agglomerate (see DIN 53206; 1972).

Further disintegration of the aggregates into smaller entities may occur during the polishing step applied to the surface of the composition containing the aggregate filler, rather than during the dispersion of the aggregate particles in the resin.

Methods of aggregating fillers and their production and surface treatment are described, for example, in U.S. Pat. No. 6,730,156 B1 (Windisch et al) and U.S. Pat. No. 6,730,156 (Windisch et al).

The term "associated" refers to a grouping of two or more primary particles that are aggregated and/or agglomerated.

Similarly, the term "non-associated" refers to two or more primary particles that are free or substantially free of aggregation and/or agglomeration.

By "non-agglomerated filler" is meant that the filler particles are present in the resin in discrete, non-associated (i.e., non-agglomerated and non-agglomerated) phases. If desired, this can be demonstrated by TEM microscopy.

"Acid-reactive filler or glass" shall mean a filler or glass that reacts chemically in the presence of an acidic component.

"Non-acid-reactive filler" shall mean a filler that, if mixed with a (poly) acid, shows no chemical reaction at all or only reduced (i.e. time delayed) reaction within 6 minutes.

In order to distinguish between acid-reactive and non-acid-reactive fillers, the following tests may or will be performed:

preparing a composition by mixing part P and part L in a mass ratio of 3:1, wherein:

Part P contains 100% by weight of the filler to be analyzed.

Part L contains poly (acrylic co-maleic acid) (Mw: about 18,000+/-3,000) 43.6 wt.%, water 47.2 wt.%, tartaric acid 9.1 wt.%, benzoic acid 0.1 wt.%.

If the shear stress is less than 50,000Pa within 6 minutes after the preparation of the above composition, the filler is characterized as non-acid reactive as measured by using a rheometer by oscillating measurements using an 8mm plate, 0.75mm gap, at 28℃with a frequency of 1.25Hz, deformation of 1.75%.

"Cationically reduced aluminosilicate glass" shall mean a glass having a lower cation content in the surface region of the glass particles than in the interior region of the glass particles.

These glasses react much slower when contacted with a solution of polyacrylic acid in water than typical acid-reactive fillers. Examples of non-acid reactive fillers include quartz glass. Additional examples are given below.

Cationic reduction can be achieved by surface treatment of the glass particles. Suitable surface treatments include, but are not limited to, acid washing (e.g., with phosphoric acid or with hydrochloric acid), phosphate treatment, or treatment with a chelating agent such as tartaric acid.

By "dispersed within the resin" is meant that the filler particles are present in the resin as agglomerated or aggregated or discrete (i.e., non-associated, non-agglomerated, and non-aggregated) particles.

"Carbamate" is a group having the structure "-NH-CO-O-".

"Ureido" is a group having the structure "-NH-CO-NH-".

"Amido" is a group having the structure "-NH-CO-".

The term "visible light" is used to refer to light having a wavelength of about 400 nanometers (nm) to about 800 nm.

By "dental article" is meant an article to be used in the dental field, in particular as or for the production of dental restorations. Dental articles typically have two distinct surface portions, an outer surface and an inner surface. The outer surface is a surface that is not normally in permanent contact with the tooth surface. In contrast, the inner surface is the surface used to attach or secure the dental article to the tooth. If the dental article has the shape of a crown, the inner surface generally has a concave shape and the outer surface generally has a convex shape. The dental article should not contain components that are detrimental to the health of the patient and therefore contain no hazardous and toxic components that can migrate out of the dental or orthodontic article.

By "dental restoration" is meant a dental article for restoring a tooth to be treated. Examples of dental restorations include crowns, bridges, inlays, onlays, veneers, coping, crown-bridge backbones, and portions thereof. An "adhesive" or "dental adhesive" refers to a composition that is used as a pretreatment on a dental structure (e.g., a tooth) to adhere "dental material" (e.g., a "restoration," an orthodontic appliance (e.g., bracket) or "orthodontic adhesive") to a dental surface. "orthodontic adhesive" refers to a composition used to adhere an orthodontic appliance to a dental (e.g., tooth) surface. Typically, the dental surface is pretreated, for example by etching, priming and/or applying an adhesive, to enhance the adhesion of the "orthodontic adhesive" to the dental surface.

"Dental surface" or "tooth surface" refers to the surface of tooth structures (e.g., enamel, dentin, and cementum) and bone. A composition is "substantially or essentially free" of a component if the composition does not contain that component as an essential feature. Thus, the component itself is not intentionally added to the composition or the component is not intentionally added to the composition along with other components or ingredients of other components.

Compositions that are substantially free of a component typically contain the component in an amount of less than about 1 wt.%, or less than about 0.5 wt.%, or less than about 0.1 wt.%, or less than about 0.01 wt.%, relative to the total composition or material. The composition may be free of said components at all. However, the presence of small amounts of said components is sometimes unavoidable, for example due to impurities contained in the raw materials used.

By "ambient conditions" is meant the conditions to which the compositions described herein are typically subjected during storage and handling. The ambient conditions may be, for example, a pressure of 900 mbar to 1,100 mbar, a temperature of 10 ℃ to 40 ℃ and a relative humidity of 10% to 100%. In the laboratory, the environmental conditions are typically adjusted to 20 ℃ to 25 ℃ and 1,000 mbar to 1,025 mbar (at sea level).

As used herein, "a," "an," "the," "at least one," and "one or more" are used interchangeably. Also herein, recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

The addition of "plural forms" to a term means that the term shall include both the singular and plural forms. For example, the term "additive" refers to one additive and multiple additives (e.g., 2, 3, 4, etc.).

Unless otherwise indicated, all numbers expressing quantities of ingredients, physical property measurements such as those described below, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about".

The terms "comprising" or "including" and variations thereof are not intended to be limiting when these terms are presented in the specification and claims. "consisting essentially of" means that certain additional components may be present, i.e., those components that do not substantially affect the basic characteristics of the article or composition. "consisting of" means that no additional components should be present. The term "comprising" shall also include that the term "consists essentially of the composition" and "the following. Composition of.

A composition is "substantially or essentially free" of a component if the composition does not contain that component as an essential feature. Thus, the component itself is not intentionally added to the composition or the component is not intentionally added to the composition along with other components or ingredients of other components. Compositions that are substantially free of a component generally do not contain the component at all. However, the presence of small amounts of said components is sometimes unavoidable, for example due to impurities contained in the raw materials used.

Detailed Description

The surface treated fillers described herein have been found to have several advantageous properties.

The surface treatment of filler particles not only renders the filler particles more compatible with the resin matrix of the dental composition, but also affects the rheological properties, in particular the viscosity distribution, of the dental composition containing these surface treated filler particles.

The dental composition becomes more flowable and can be more easily dispensed from the syringe-like packaging material.

In particular, dental compositions have low viscosity at low shear rates, which is an indication of lack of internal structure, similar to newtonian liquids.

In addition, it has been found that the hardened dental composition still has sufficient mechanical properties such as flexural strength and flexural modulus.

Without wishing to be bound by a particular theory, it is believed that the length of the two alkylene moieties works and that it is important that the length of the alkylene moiety AM1 is longer than the length of the alkylene moiety AM 2. Thus, the urethane moiety should be located closer to the hydrolyzable silane moiety than the (meth) acryl moiety.

It is speculated that by selecting the length suggested herein, the likelihood of formation of undesirable hydrogen bridges is reduced and the surface treatment agent is more effective in shielding the surface of the treated filler.

According to one aspect, the present invention relates to a surface treated filler.

The nature and structure of the filler are not particularly limited unless the intended purpose cannot be achieved. Different types of filler may be used.

The dental compositions described herein may include one or more of filler (F1), filler (F2), filler (F3), filler (F4), filler (F5), or filler (F6).

The dental composition may contain only one filler (F1) or a plurality of fillers (F1), for example two, three or four different fillers.

The dental composition may contain only one filler (F2) or a plurality of fillers (F2), for example two, three or four different fillers.

The dental composition may contain only one filler (F3) or a plurality of fillers (F3), for example two, three or four different fillers.

The dental composition may contain only one filler (F4) or a plurality of fillers (F4), for example two, three or four different fillers.

The dental composition may contain only one filler (F5) or a plurality of fillers (F5), for example two, three or four different fillers.

The dental composition may contain only one filler (F6) or a plurality of fillers (F6), for example two, three or four different fillers.

Generally, the dental composition generally contains filler in an amount of at least 40 wt%, or 45 wt%, or 50 wt%, up to 80 wt%, or 75 wt%, or 70 wt%, in the range of 40 wt% to 80 wt%, or 45 wt% to 75 wt%, or 50 wt% to 70 wt%, relative to the weight of the dental composition.

The filler (F1) comprises non-aggregated, non-agglomerated nano-sized particles of SiO ₂、ZrO₂ and mixtures thereof.

The nano-sized particles are preferably substantially spherical and substantially non-porous.

The filler (F1) may generally be characterized by at least one or all of the following features:

a) Specific surface area (BET) 50m ²/g to 400m ²/g, or 60m ²/g to 300m ²/g, or 80m ²/g to 250m ²/g;

b) Primary particle size 5nm to 30nm, or 7nm to 20nm;

c) Particles comprising SiO ₂、ZrO₂ and mixtures thereof.

Fillers (F1) characterized by features a) and c) are sometimes preferred.

If desired, the specific surface area can be determined by using a device (Monosorb) from Kangaroo, inc. (Quantachrome) according to Brunauer, emmet and Teller (BET).

Silica is an example of a preferred nano-sized filler (F1). Although the silica is preferably substantially pure, it may contain small amounts of stabilizing ions, such as ammonium and alkali metal ions.

Zirconia is another preferred nano-sized filler (F1). A useful method for preparing zirconia is described, for example, in U.S. Pat. No. 6,376,590 B1 (Kolb et al).

The application discloses a zirconia sol comprising an aqueous phase having dispersed therein a plurality of single crystal zirconia particles having an average primary particle size of less than 20nm, preferably from 7nm to 20 nm. Zirconia sols are substantially non-associative (i.e., non-aggregated and non-agglomerated).

Non-agglomerated nanosized silica is commercially available, for example, from Nalco Chemical co (Nalco Chemical co. (Naperville, ill.)) in state of il, us under product name NALCO COLLOIDAL SILICAS, e.g., nalco product numbers 1040, 1042, 1050, 1060, 2327, and 2329. Non-aggregated fillers are used and described, for example, in US 7,393,882 (3M).

The filler (F2) comprises aggregated nano-sized particles.

The filler (F2) can generally be characterized by the following features, alone or in combination:

a) Specific surface area (BET) of 30m ²/g to 400m ²/g, or 50m ²/g to 400m ²/g, or 60m ²/g to 300m ²/g, or 80m ²/g to 250m ²/g;

b) Primary particle size 5nm to 100nm or 10nm to 80nm or 10nm to 50nm;

c) Average particle size (aggregate) of 0.5 μm to 2 μm;

d) Particles comprising SiO ₂、ZrO₂ and mixtures thereof.

Fillers (F2) characterized by the features a) and c), or a) and d), or a), c) and d) are sometimes preferred.

According to one embodiment, the filler (F2) is characterized by a primary particle size in the range from 50nm to 100nm and a specific surface area (BET) in the range from 30m ²/g to 50m ²/g.

If desired, the average particle size may be determined by light scattering using, for example, a Malvern Mastersizer 2000 apparatus available from Markov instruments (Malvern Instruments).

The filler (F2) may be produced according to the method described in, for example, U.S. Pat. No.6,730,156 B1 (Windisch et al).

In particular, the filler (F2) may be prepared from a suitable sol and one or more oxygen-containing heavy metal compound solution precursors, which may be salts, sols, solutions or nano-sized particles, with sols being preferred. For the purposes of the present invention, a sol is defined as a stable dispersion of colloidal solid particles in a liquid. The solid particles are typically denser than the surrounding liquid and small enough so that the dispersion force is greater than gravity. Furthermore, the size of the particles is small enough that they typically do not refract visible light. The judicious choice of precursor sol results in a desired degree of visual opacity, intensity, etc. The factors governing the selection of the sol depend on a) the average size of the individual particles, which is preferably less than about 100nm in diameter, b) the acidity, that the pH of the sol should preferably be below 6, more preferably below 4, and c) the sol should be free of impurities that cause excessive aggregation of the individual discrete particles during subsequent steps (such as spray drying or calcination) (during the filler preparation process) to larger sized particles that cannot be easily dispersed or commutated and thus reduce translucency and polishability.

If the starting sol is basic, it should be acidified, for example by adding nitric acid or other suitable acid, to lower the pH. However, the choice of an alkaline starting sol is less desirable because it requires additional steps and may lead to the introduction of undesirable impurities. Typical impurities which are preferably avoided are metal salts, in particular alkali metal salts, for example sodium salts.

The non-heavy metal sol and the heavy metal oxide precursor are preferably mixed together in a molar ratio that matches the refractive index of the hardenable resin. This imparts low and desirable visual opacity. Preferably, the molar ratio of non-heavy metal oxide ("non-HMO") to heavy metal oxide ("HMO") (expressed as non-HMO: HMO) ranges from 0.5:1 to 10:1, more preferably from 3:1 to 9:1, and most preferably from 4:1 to 7:1.

In a preferred embodiment, wherein the aggregated nano-sized particles comprise silica and a zirconium-containing compound, the preparation method starts with a mixture of silica sol and zirconyl acetate in a molar ratio of about 5.5:1.

The pH of the non-heavy metal oxide sol is preferably reduced to provide an acidic solution having a pH of 1.5 to 4.0 prior to mixing the non-heavy metal oxide sol with the heavy metal oxide precursor.

The non-heavy metal oxide sol is then slowly mixed with the solution containing the heavy metal oxide precursor and vigorously stirred. Preferably, vigorous stirring is performed throughout the blending process. The solution is then dried to remove water and other volatile components. Drying may be accomplished in a variety of ways including, for example, tray drying, fluidized bed, and spray drying. In a preferred method of using zirconyl acetate, drying is performed by spray drying.

The resulting dry material is preferably composed of small substantially spherical particles and broken hollow spheres. These fragments were then calcined in batches to further remove residual organics. The removal of residual organics causes the filler to become more brittle, which results in a more effective particle size reduction. During calcination, the soaking temperature is preferably set to 200 ℃ to 800 ℃, more preferably 300 ℃ to 600 ℃. The soaking is performed for 0.5 to 8 hours depending on the amount of the calcined material. Preferably, the soaking time of the calcination step is such that a plateau surface area is obtained. Preferably, the time and temperature are selected such that the resulting filler is white, free of black, gray or amber particles, as determined by visual inspection.

The calcined material is then preferably milled to a median particle size of less than 5 μm, preferably less than 2 μm (on a volume basis), as can be determined by using a Sedigraph 5100 (micromrics, norcross, ga.) of nococromis, georgia. Particle size determination can be performed by first obtaining the specific density of the filler using Accuracy 1330 Pycometer (mike of nocorks, georgia). Milling may be accomplished by a variety of methods including, for example, agitation milling, vibratory milling, fluid energy milling, jet milling, and ball milling. Ball milling is the preferred method.

The resulting filler comprises, contains, consists essentially of, or consists of aggregated nano-sized particles. If desired, this can be demonstrated by Transmission Electron Microscopy (TEM).

Once dispersed in the resin, the filler (F2) remains in the aggregation stage. That is, during the dispersing step, the particles do not break up into discrete (i.e., individual) and unassociated (i.e., non-agglomerated, non-aggregated) particles.

Without wishing to be bound by a particular theory, it is believed that filler (F2) contributes to the polishability of the dental compositions described herein. It was found that the aggregates of filler (F2) particles can break during the polishing step, contributing to a smooth surface and lower light scattering compared to a rough surface. From a clinical point of view, this generally results in a high gloss retention and color stability.

If present, filler (F2) is typically present in an amount of at least 30 wt%, or 35 wt%, or 40 wt%, up to 70 wt%, or 60 wt%, or 50 wt%, in the range of 30 wt% to 70 wt%, or 35 wt% to 60 wt%, or 40 wt% to 50 wt%, relative to the weight of the dental composition.

The filler (F3) may comprise agglomerated nano-sized particles.

According to one embodiment, the filler (F3) can be characterized by the following features, alone or in combination:

a) Specific surface area (BET) of 30m ²/g to 400m ²/g, or 50m ²/g to 300m ²/g, or 70m ²/g to 250m ²/g;

b) Particles comprising SiO ₂、ZrO₂、Al₂O₃ and mixtures thereof.

If desired, the specific surface area can be determined as described above.

Suitable agglomerated nanoparticles include fumed silica such as the products sold under the trade name Aerosil ^™, e.g., aerosil OX-130, aerosil OX-150, and Aerosil OX-200, aerosil R8200 available from Desoxhlet corporation (Hanau, germany), CAB-O-SIL ^™ M5 available from Kabot corporation (Tuscola, ill.) and HDK ^™, e.g., HDK-H2000, HDK H15, HDK H18, HDK H20, and HDK H30 available from Wake corporation.

Without wishing to be bound by a particular theory, it is believed that filler (F2) contributes to the rheological behavior of the dental compositions described herein.

The use of such fillers can provide highly filled dental compositions, yet they can still be mixed using a static mixing tip. From a clinical point of view, this generally results in improved handling characteristics such as easy mixing of the paste and low extrusion forces from the cartridge system.

If present, filler (F3) is typically present in an amount of at least 1wt%, or 3 wt%, or 5 wt%, up to 20 wt%, or 15 wt%, or 10wt%, in the range of 1wt% to 20 wt%, or 3 wt% to 15 wt%, or 5 wt% to 10wt%, relative to the weight of the dental composition.

The filler (F4) comprises non-acid-reactive glasses such as lanthanum glass, borosilicate glass, sodium glass, barium glass, strontium glass, glass ceramics, aluminosilicate glass, barium alumino silicate glass, strontium alumino silicate glass, silicates such as calcium silicate, zirconium silicate, and metal oxides such as quartz, cristobalite, alumina, titania, silica-titania-barium oxide, silica-zirconia, silica-alumina.

In particular, barium glass, strontium glass, aluminosilicate glass, barium boroaluminosilicate glass, and strontium boroaluminosilicate glass have been found to be useful.

Useful glasses are commercially available, for example, from Schottky (Schott), such as GM32087, GM27884, G018-053, G018-308, G018-431 and G018-432.

If desired, the filler (F4) can also be characterized by the following features, alone or in combination:

a) Specific surface area (BET) of 10m ²/g to 50m ²/g, or 15m ²/g to 40m ²/g;

b) Average particle size 0.1 μm to 1 μm, or 0.2 μm to 0.6 μm.

If present, filler (F4) is typically present in an amount of at least 1 wt%, or 5 wt%, or 10 wt%, up to 80 wt%, or 70 wt%, or 60 wt%, in the range of 1 wt% to 80 wt%, or 5 wt% to 70 wt%, or 10 wt% to 60 wt%, relative to the weight of the dental composition.

The filler (F5) comprises an acid-reactive filler, in particular an acid-reactive glass.

The acid-reactive filler may help to adjust the curing behavior and adhesion of the dental composition by adjusting the pH during the hardening process.

The acid-reactive filler can generally be characterized by the following features, alone or in combination:

a) Average particle size of about 3 μm to about 10 μm;

b) (d 10/μm) 0.5 μm to 3 μm, (d 50/μm) 2 μm to 7 μm and (d 90/μm) 6 μm to 15 μm.

Examples of the filler (F5) include metal oxides and hydroxides, such as oxides and hydroxides of calcium, magnesium or zinc, with calcium hydroxide sometimes being preferred, and acid-reactive glasses, particularly fluoroaluminosilicate glasses (FAS glasses).

The acid-reactive glass can be produced by melting a glass frit containing the corresponding glass component, pulverizing, and grinding until a desired particle size distribution is obtained. Glass components that may be used include Al ₂O₃、SiO₂、SrF₂ and AlF ₃ -hydrate or AlF ₃. Grinding or milling of the frit may be performed, for example, with a ball mill.

The Al/Si ratio of the acid-reactive glass is generally greater than 1/1 (relative to weight). This means that the acid-reactive glass contains more Al than Si. Al/Si ratios in the range of greater than 1.0/1.0 to 1.6/1.0 or greater than 1.0/1.0 to 1.4/1.0 are generally preferred.

If present, filler (F5) is typically present in an amount of at least 1 wt%, or 5 wt%, or 10 wt%, up to 80 wt%, or 70 wt%, or 60 wt%, in the range of 1 wt% to 80 wt%, or 5 wt% to 70 wt%, or 10 wt% to 60 wt%, relative to the weight of the dental composition.

The filler (F6) contains a heavy metal oxide and a fluoride. The filler (F6) may help to increase the radiopacity of the composition.

"Radiopacity" describes the ability to distinguish hardened dental material from tooth structure in a conventional manner using standard dental X-ray equipment. Radiopacity of dental materials is advantageous in certain situations where X-rays are used to diagnose dental conditions. For example, a radiopaque material will allow detection of secondary caries that may have formed in dental tissue surrounding the filling.

Oxides or fluorides of heavy metals having an atomic number greater than 28 may be preferred. The heavy metal oxide or fluoride should be selected such that an undesired color or shade is not imparted to the hardening resin in which the heavy metal oxide or fluoride is dispersed. For example, iron and cobalt are disadvantageous in that they impart dark and contrasting colors to neutral teeth of dental materials. More preferably, the heavy metal oxide or fluoride is an oxide or fluoride of a metal having an atomic number greater than 30. Suitable metal oxides are oxides of yttrium, strontium, barium, zirconium, hafnium, niobium, tantalum, tungsten, bismuth, molybdenum, tin, zinc, lanthanides (i.e., elements having an atomic number in the range of 57-71, inclusive), cerium, and combinations thereof. Suitable metal fluorides are, for example, yttrium trifluoride and ytterbium trifluoride. Most preferably, oxides and fluorides of heavy metals having atomic numbers greater than 30 but less than 72 are optionally included in the materials of the present invention. Particularly preferred radiopaque metal oxides include lanthanum oxide, zirconium oxide, yttrium oxide, ytterbium oxide, barium oxide, strontium oxide, cerium oxide, and combinations thereof. Heavy metal oxide particles may aggregate. If so, it is preferable that the average diameter of the aggregated particles is 200nm or less. Other suitable fillers to improve radiopacity are barium and strontium salts, in particular strontium and barium sulphate.

If present, filler (F6) is typically present in an amount of at least 1wt%, or 3 wt%, or 5 wt%, up to 50 wt%, or 40 wt%, or 30 wt%, in the range of 1wt% to 50 wt%, or 3 wt% to 40 wt%, or 5 wt% to 30 wt%, relative to the weight of the dental composition.

In certain embodiments, the dental composition may comprise a combination of fillers (F1) and (F2), or (F1) and (F3), or (F2) and (F6), or (F1), (F2) and (F6), or (F2), (F3) and (F6), wherein a combination of fillers (F2) and (F6) is sometimes preferred.

The surface treating agent is characterized by comprising the following components:

a. Comprising at least one (meth) acrylate moiety,

B. comprising at least one hydrolyzable silane moiety,

C. Comprising only one urethane moiety,

D. Comprising a linear alkylene moiety AM1 linking at least one (meth) acrylate moiety to a urethane moiety,

E. Comprising a linear alkylene moiety AM2 linking at least one hydrolyzable silane moiety to a carbamate moiety,

F. The linear alkylene moiety AM1 contains more carbon atoms than the linear alkylene moiety AM 2.

The surface treatment agent does not contain a polyol moiety (e.g., a polyethylene or polypropylene moiety).

Without wishing to be bound by a particular theory, the presence of a combination of polyol moieties and urethane moieties may result in interactions through hydrogen bonding and may create undesirable internal structures within the composition.

More precisely, the surface treatment agent may be characterized as follows:

a. comprising only one (meth) acrylate moiety,

B. comprising at least one hydrolyzable silane moiety,

C. Comprising only one urethane moiety,

D. comprising one linear alkylene moiety AM1 linking the (meth) acrylate moiety to the urethane moiety, the alkylene moiety AM1 comprising 6 to 12C atoms,

E. Comprising one linear alkylene moiety AM2 linking at least one hydrolyzable silane moiety to a carbamate moiety, the linear alkylene moiety AM2 comprising 1 to 4C atoms.

The hydrolyzable portion of the silane moiety is typically selected from

-Si(R²)_o(R³)_3-o

Wherein R ¹ = H or CH ₃;R² = independently selected from Cl, br, O-C _1-4 alkyl, O-C _1-4 acyl, R ³ = independently selected from C _1-4 alkyl, X = O, Y = NH, n = 6 to 12, m = 1 to 4;o = 1 to 3.

Preferred are generally trialkoxysilanes, in particular trimethoxysilane, triethoxysilane, tripropoxysilane or tributoxysilane moieties.

Even more precisely, the surface treatment agent may be characterized by the following formula:

H₂C=CHR¹-CO-O-(CH₂)_n-X-CO-Y-(CH₂)_m-Si(R²)_o(R³)_3-o

Preferred embodiments of the hydrolyzable silane moiety are represented by the following formula:

H₂C=CHR¹-CO-O-(CH₂)_n-X-CO-Y-(CH₂)_m-SiR² ₃

Wherein R ¹ = H or CH ₃;R² = independently selected from Cl、Br、OCH₃、OCH₂CH_3、OCH₂CH₂CH₃、OCH₂CH₂CH₂CH₃;X=O;Y=NH;n=6 to 12 and m = 1 to 4.

The surface treatment agent typically has a molecular weight (Mw) in the range of 300g/mol to 800g/mol or 350g/mol to 600 g/mol.

Specific examples of the surface treatment agent include the following molecules:

The surface treatment agent may be prepared by a method comprising the steps of:

allowing a (meth) acrylate component comprising a hydroxyl moiety

With a hydrolyzable isocyanate silane component.

The reaction is typically carried out at a slightly elevated temperature (e.g., 40 ℃ to 80 ℃).

The surface treated filler may be prepared by a process comprising the steps of:

Reacting the surface treatment agent with the filler particles,

The optional dispersion liquid is removed and the solution is mixed,

Optionally drying and sieving the surface-treated filler particles.

Suitable dispersions include water and alcohols such as methanol, ethanol or propanol. The pH of the dispersion can be adjusted, if desired, for example by adding aqueous ammonia.

In some embodiments, the reaction of the surface treatment agent with the filler particles consists of hydrolysis (i.e., reaction of water with at least one of the hydrolyzable silane groups) and condensation of the resulting silanol groups with the filler surface and/or another surface treatment agent molecule. In some embodiments, the surface treated filler comprises a partially or fully hydrolyzed surface treatment agent. In some embodiments, the partially or fully hydrolyzed surface treatment agent is fully or partially condensed to form siloxane bonds between adjacent surface treatment agent molecules, or between the surface treatment agent and the filler surface. In some embodiments, some portions of the hydrolyzed and/or condensed surface treatment agent may be removed from the surface treated filler by a re-esterification reaction, i.e., immersing the surface treated filler in an alcohol with an effective catalyst to reform hydrolyzable silane moieties. Useful catalysts may include, but are not limited to, hydrofluoric acid, sodium fluoride, tetramethyl ammonium fluoride, tetrabutyl ammonium fluoride, hydrochloric acid, p-toluene sulfonic acid, and trifluoromethane sulfonic acid.

According to another aspect, the present invention relates to a dental composition comprising a surface treated filler as described herein.

Dental compositions generally comprise a filler system, a resin matrix, and an initiator system. The filler system comprises a surface treated filler as described herein. The resin matrix comprises a curable component.

Dental compositions can generally be characterized prior to hardening by the following properties, alone or in combination:

Can harden within 10 minutes after irradiation with light having a wavelength in the range of 400nm to 700 nm;

The pH is 7 or less.

Dental compositions that do not contain rheology modifiers typically have a shear rate of 5Pa at 25℃and 0.01s ^-1 S to 1,500PaViscosity in the s range.

Dental compositions can generally be characterized after hardening by the following properties, alone or in combination:

flexural strength from 100MPa to 200MPa, determined according to ISO 4049 (2019);

Flexural modulus from 4GPa to 8GPa, determined according to ISO 4049 (2019).

If desired, the characteristics may be determined as described in the examples section.

The dental composition comprises a curable component.

The curable component is part of the resin matrix. One or more different curable components may be present.

The curable component typically comprises one or more polymerizable moieties, in particular (meth) acrylate moieties. Furthermore, the curable component may or may not contain an acidic moiety.

The curable component is typically present in an amount of at least 5 wt%, or 10 wt%, or 15 wt%, up to 50 wt%, or 45 wt%, or 40 wt%, in the range of 5 wt% to 50 wt%, or 10 wt% to 45 wt%, or 15 wt% to 40 wt%, with respect to the dental composition.

Suitable polymerizable components that may be used that do not contain an acidic moiety are characterized by the formula:

A_nBA_m

Wherein A is an ethylenically unsaturated group such as a (meth) acryl moiety,

B is selected from (I) a linear or branched C ₁ to C ₁₂ alkyl group optionally substituted with other functional groups (e.g., including Cl, br, I, OH, or mixtures thereof), (ii) a C ₆ to C ₁₂ aryl group optionally substituted with other functional groups (e.g., halogen, OH, or mixtures thereof), or (iii) an organic group having 4 to 20 carbon atoms bonded to each other through one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl, and/or sulfonyl linkages,

M, n are independently selected from 0,1, 2, 3, 4, 5 or 6, provided that n+m is greater than 0, i.e., at least one A group is present.

Such polymerizable materials include

Monoacrylate, diacrylate or polyacrylate and methacrylate esters, such as methyl acrylate, methyl methacrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, allyl (meth) acrylate, glycerol di (meth) acrylate,

Urethane dimethacrylates (mixtures of isomers, e.g., plex 6661-0) known as UDMA are the reaction products of 2-hydroxyethyl methacrylate (HEMA) and 2, 4-trimethyl-hexamethylene diisocyanate (TMDI);

glycerol tri (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate (TEGDMA), 1, 3-propanediol diacrylate, 1, 3-propanediol dimethacrylate, 1, 6-hexanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, 1, 12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,2, 4-butanetriol tri (meth) acrylate, 1, 4-cyclohexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethyl acrylate, sorbitol hexa (meth) acrylate, bis [1- (2- (meth) acryloxy) ] -p-ethoxy-phenyl dimethyl methane, and trihydroxyethyl-isocyanurate trimethacrylate;

Diacrylates and dimethacrylates of polyethylene glycols having molecular weights of 200 to 500, copolymerizable mixtures of acrylated monomers (see, e.g., U.S. Pat. No. 4,652,274 (Boettcher et al)) and acrylated oligomers (see, e.g., U.S. Pat. No. 4,642,126 (Zador));

Vinyl compounds such as styrene, divinyl succinate, divinyl adipate and divinyl phthalate, and

Multifunctional (meth) acrylates comprising urethane, urea or amide groups.

Mixtures of two or more of these radically polymerizable materials may be used if desired.

The polymerizable component, if present, without acidic moieties is typically present in an amount of at least 1 wt%, or at least 2 wt%, or at least 5 wt%, up to 20 wt%, or up to 15 wt%, or up to 10 wt%, in the range of 1 wt% to 20 wt%, or 2 wt% to 15 wt%, or 5 wt% to 10 wt%, wt% relative to the weight of the dental composition.

The dental composition may further comprise a polymerizable monomer having an acidic moiety.

The polymerizable component having an acid moiety can be generally characterized by the following formula

A_nBC_m

Wherein A is an ethylenically unsaturated group such as a (meth) acryl moiety,

B is a spacer group such as (I) a linear or branched C ₁ to C ₁₂ alkyl group optionally substituted with other functional groups (e.g., halogen (including Cl, br, I), OH, or mixtures thereof), (ii) a C ₆ to C ₁₂ aryl group optionally substituted with other functional groups (e.g., halogen, OH, or mixtures thereof), (iii) an organic group having 4 to 20 carbon atoms bonded to each other through one or more ether, thioether, ester, thioester, thiocarbonyl, amide, carbamate, carbonyl, and/or sulfonyl bonds, and

C is an acidic group, or a precursor of an acidic group, such as an anhydride,

M, n are independently selected from 1, 2, 3, 4, 5 or 6,

Wherein the acidic group comprises one or more carboxylic acid residues, such as-COOH or-CO-O-CO-, phosphoric acid residues, such as-O-P (O) (OH) OH, phosphonic acid residues, such as C-P (O) (OH) (OH), sulfonic acid residues, such as-SO ₃ H, or sulfinic acid residues, such as-SO ₂ H.

Examples of polymerizable components having an acid moiety include glycerol mono (meth) acrylate, glycerol di (meth) acrylate, hydroxyethyl (meth) acrylate (e.g., HEMA) phosphate, bis ((meth) acryloyloxyethyl) phosphate, (meth) acryloyloxypropyl phosphate, bis ((meth) acryloyloxypropyl) phosphate, bis ((meth) acryloyloxypropoxy phosphate, (meth) acryloyloxyhexyl phosphate, bis ((meth) acryloyloxyhexyl) phosphate, (meth) acryloyloxyoctyl phosphate, bis ((meth) acryloyloxyoctyl) phosphate, (meth) acryloyloxydecyl phosphate, bis ((meth) acryloyloxydecyl) phosphate, caprolactone methacrylate phosphate, citric acid dimethacrylate or trimethacrylate, poly (meth) acrylated oligomaleic acid, poly (meth) acrylated polymaleic acid, poly (meth) acrylated poly (meth) acrylic acid, poly (meth) acrylated carboxypoly (meth) acrylic acid, poly (meth) acrylated poly (meth) acrylic acid ester, poly (meth) acrylated sulfonic acid ester, and the like. Derivatives of these hardenable components with acid moieties, such as acid halides or anhydrides, which can readily react with, for example, water to form the specific examples described above are also contemplated.

Monomers, oligomers, and polymers of unsaturated carboxylic acids such as (meth) acrylic acid, aromatic (meth) acrylated acids (e.g., methacrylated trimellitic acid), and anhydrides thereof can also be used.

Some of these compounds may be obtained, for example, as a reaction product between an isocyanatoalkyl (meth) acrylate and a carboxylic acid. Additional compounds of this type having an acid function and an ethylenically unsaturated component are described in U.S. Pat. No. 4,872,936 (Engelbrecht) and U.S. Pat. No. 5,130,347 (Mitra). A variety of such compounds containing an ethylenically unsaturated moiety and an acid moiety may be used. Mixtures of such compounds may be used if desired.

The use of (meth) acrylate functionalized polyolefin acids is generally preferred because those components have been found to be useful in improving properties such as adhesion to hard dental tissue, formation of a uniform layer, viscosity or moisture resistance.

According to one embodiment, the composition contains a (meth) acrylate functionalized polyalkenic acid, such as AA: ITA: IEM (acrylic acid: copolymer of itaconic acid and pendant methacrylate).

These components can be prepared by reacting, for example, an AA: ITA copolymer with 2-isocyanatoethyl methacrylate to convert a portion of the acid groups of the copolymer to pendant methacrylate groups. Methods for producing these components are described in example 11 of example U.S. Pat. No. 5,130,347 (Mitra), and those listed in U.S. Pat. No. 5,4,259,075 (Yamauchi et al), U.S. Pat. No. 4,499,251 (Omura et al), U.S. Pat. No. 5,4,537,940 (Omura et al), U.S. Pat. No. 4,539,382 (Omura et al), U.S. Pat. No. 5,530,038 (Yamamoto et al), U.S. Pat. No. 6,458,868 (Okada et al), EP 0,712,622 A1 (Tokuyama Corp.), and EP 1 051 961 A1 (Colales Co., ltd.).

The polymerizable component having an acidic moiety, if present, should be present in an amount such that the pH of the composition is below 6, or below 4, or below 2, if contacted with water.

The polymerizable component having an acidic moiety, if present, is typically present in an amount of at least 1 wt%, or at least 2 wt%, or at least 5 wt%, up to 20 wt%, or up to 15 wt%, or up to 10 wt%, in the range of 1 wt% to 20 wt%, or 2 wt% to 15 wt%, or 5 wt% to 10 wt%, with wt% relative to the weight of the dental composition.

If desired, an Addition Fragmentation Monomer (AFM) may also be added.

The addition fragmentation monomer can be characterized by the following formula:

Wherein the method comprises the steps of

R ¹、R² and R ³ are each independently Z _m -Q-, (hetero) alkyl groups or (hetero) aryl groups, with the proviso that at least one of R ¹、R² and R ³ is Z _m -Q-, Q is a linking group having a valence of m+1, Z is an ethylenically unsaturated polymerizable group, m is 1 to 6, each X ¹ is independently-O-or-NR ⁴ -, wherein R ⁴ is H or C ₁-C₄ alkyl, and n is 0 or 1.

These monomers are said to have lower stress. Suitable monomers are also described in US 9,056,043 (Joly et al).

Monomers containing hydroxyl moieties may also be present.

Suitable compounds include 2-hydroxyethyl (meth) acrylate (HEMA), 2-or 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, dialkylene glycol mono (meth) acrylate (e.g., diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate), and further adducts of 1, 2-or 1, 3-and 2, 3-dihydroxypropyl (meth) acrylate, 2-hydroxypropyl-1, 3-di (meth) acrylate, 3-hydroxypropyl-1, 2-di (meth) acrylate, N- (meth) acryl-1, 2-dihydroxypropylamine, N- (meth) 1, 3-dihydroxypropylamine, phenol (meth) acrylate, glycidyl (meth) acrylate), 1-phenoxy-2-hydroxypropyl (meth) acrylate and 1-naphthoxy-2-hydroxypropyl (meth) acrylate.

Mixtures of one or more of these components may be used if desired.

The dental composition further comprises an initiator system suitable for curing the curable component.

The initiator system may be a redox initiator system, a photoinitiator system or a thermal curing system. The initiator system is capable of initiating the curing process of the hardenable component present in the resin matrix.

The initiator system is typically present in an amount of at least 0.1 wt%, or at least 0.2 wt%, or at least 0.5 wt%, up to 5 wt%, or up to 4 wt%, or up to 3 wt%, in the range of 0.1 wt% to 5 wt%, or 0.2 wt% to 4 wt%, or 0.5 wt% to 3 wt%, with wt% relative to the weight of the dental composition.

To cure one-part compositions, a photoinitiator system is typically used.

Suitable photoinitiator systems for free radical polymerization are generally known to those skilled in the art of treating dental materials.

Suitable photoinitiator systems typically contain a sensitizer comprising an alpha-alpha diketone moiety, an anthraquinone moiety, a thioxanthone moiety or a benzoin moiety. Sensitizers containing an α - α diketone moiety are generally preferred.

Typical photoinitiator systems include a combination of a sensitizer and a reducing agent or donor component, which is commonly referred to as a photoinitiator system.

As the sensitizer, those which polymerize the polymerizable monomer by the action of visible light having a wavelength of 390nm to 830nm are preferable.

Examples of sensitizers that may be used include camphorquinone, benzil, diacetyl, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl bis (2-methoxyethyl) ketal, 4, '-dimethylbenzyl dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1, 2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2, 4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10, 10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, isopropyl ether, benzoin isobutyl ether, benzophenone, bis (4-dimethyl-aminophenyl) ketone, 4,' -diethylaminobenzophenone.

As the reducing agent or donor component, tertiary amine and the like are generally used. Suitable examples of tertiary amines include N, N-dimethyl-p-toluidine, N-dimethyl-aminoethyl methacrylate, triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, methyldiphenylamine and isoamyl 4-dimethylaminobenzoate.

Further suitable reducing agents include diarylalkylamines characterized by the formula Ar ¹Ar² RN, wherein Ar ¹ and Ar ² are independently selected from phenyl or alkyl (e.g., C ₁ to C ₄) substituted phenyl, R is an alkyl (e.g., C ₁ to C ₄) group, wherein one or more H atoms may be substituted with halogen, and N is nitrogen. These reducing agents are described in more detail in US 8,314,162 (Hailand et al).

In addition, a ternary photopolymerization initiator system composed of a sensitizer, an electron donor, and an onium salt may be used.

Examples are described in US 6,187,833 (Oxman et al), US 6,025,406 (Oxman et al), US 6,043,295 (Oxman et al), US 5,998,495 (Oxman et al), US 6,084,004 (Weinmann et al), US 5,545,676 (Palazzotto et al) and US 8,314,162 B2 (Hailand et al) and US 6,765,036 (de et al).

In a ternary photoinitiator system, the first component is an onium, preferably an iodonium salt, i.e., a diaryliodonium salt.

The iodonium salt is preferably soluble in the monomer and is storage stable (i.e., does not spontaneously promote polymerization) when dissolved therein in the presence of a sensitizer and a donor. Thus, the choice of a particular iodonium salt can depend to some extent on the particular monomer, polymer or oligomer, sensitizer and donor selected. Suitable iodonium salts are described, for example, in U.S. Pat. No. 3,729,313 history (Smith et al), U.S. Pat. No. 3,741,769, 3,808,006 (Smith et al), U.S. Pat. No. 4,250,053 (Smith et al) and U.S. Pat. No. 4,394,403 (Smith et al).

The iodonium salt can be a simple salt (e.g., containing an anion such as Cl ^-、Br^-、I^- or C ₄H₅ SO₃ ^-) or a metal complex salt (e.g., containing SbF ₅OH^- or AsF ₆ ^-). Mixtures of iodonium salts can be used if desired. Preferred iodonium salts include diphenyliodonium salts, such as diphenyliodonium chloride diphenyliodonium hexafluorophosphate diphenyliodonium tetrafluoroborate.

The second component in the ternary photoinitiator system is a sensitizer.

The sensitizer is desirably soluble in the monomer and is capable of light absorption in a wavelength range of greater than 400nm to 1,200nm, more preferably greater than 400nm to 700nm and most preferably greater than 400nm to 600 nm.

Suitable sensitizers may include classes of compounds selected from the group consisting of ketones, coumarin dyes (e.g., coumarin ketones), xanthene dyes, acridine dyes, thiazole dyes, thiazine dyes, oxazine dyes, azine dyes, aminoketone dyes, porphyrins, aromatic polycyclic hydrocarbons, para-substituted aminostyryl ketone compounds, aminotriaryl methanes, merocyanines, squaraine dyes, and pyridinium dyes. Ketones (e.g., mono-or alpha-diketones), coumarin ketones, amino aromatic ketones, and para-substituted amino styryl ketone compounds are preferred sensitizers.

For example, a preferred class of ketone sensitizers has the formula ACO (X) _b B, where X is CO or CR ⁵R⁶, where R ⁵ and R ⁶ may be the same or different and may be hydrogen, alkyl, alkylaryl or arylalkyl, B is zero or one, and A and B are different and may be substituted (with one or more non-interfering substituents) and may be the same or unsubstituted aryl, alkyl, alkylaryl or arylalkyl groups, or A and B together may form a cyclic structure which may be a substituted or unsubstituted cycloaliphatic, aromatic, heteroaromatic or fused aromatic ring.

Suitable ketones of the above formula include monoketones (b=0), such as 2,2-, 4-or 2, 4-dihydroxybenzophenone, di-2-pyridylketone, di-2-furanylketone, di-2-thienyl ketone, benzoin, fluorenone, chalcone, michaelin, 2-fluoro-9-fluorenone, 2-chlorothioxanthone, acetophenone, benzophenone, 1-or 2-naphthacene, 9-acetylanthracene, 2-, 3-or 9-acetylphenanthrene, 4-acetylbiphenyl, propiophenone, phenylbutanone, phenylpentanone, 2-, 3-or 4-acetylpyridine, 3-acetylcoumarin, and the like. Suitable diketones include aralkyl diketones such as anthraquinone, phenanthrenequinone, o-, m-and p-diacetylbenzene, 1,3-, 1,4-, 1,5-, 1,6-, 1, 7-and 1, 8-diacetylnaphthalene, 1,5-, 1, 8-and 9, 10-diacetylanthracene, and the like. Suitable α -diketones (b=1 and x=co) include 2, 3-butanedione, 2, 3-pentanedione, 2, 3-hexanedione, 3, 4-hexanedione, 2, 3-heptanedione, 3, 4-heptanedione, 2, 3-octanedione, 4, 5-octanedione, benzil, 2'-3,3' -and 4,4 '-dihydroxybenzil, furaloyl, di-3, 3' -indoloethyl dione, 2, 3-camphorquinone, diacetyl, 1, 2-cyclohexanedione, 1, 2-naphthoquinone, and the like.

The third component of the ternary initiator system is the donor.

Preferred donors include, for example, amines (including aminoaldehydes and aminosilanes), amides (including phosphoramides), ethers (including thioethers), ureas (including thiourea), ferrocenes, sulfinic acids and salts thereof, salts of ferrocyanide, ascorbic acid and salts thereof, dithiocarbamates and salts thereof, xanthates, edetates and tetraphenylborates. The donor may be unsubstituted or substituted with one or more non-interfering substituents. Particularly preferred donors contain an electron donor atom, such as a nitrogen, oxygen, phosphorus or sulfur atom, and an abstractable hydrogen atom bonded to the alpha carbon or silicon atom of the electron donor atom. A variety of donors are disclosed in U.S. Pat. No. 5,545,676 (Palazzotto et al).

Alternatively, free radical initiators that may be used include acyl phosphine oxides and bisacylphosphine oxides.

Suitable acylphosphine oxides may be described by the general formula:

(R⁹)2 - P(=O) - C(=O)-R¹⁰

Wherein each R ⁹ independently can be a hydrocarbyl group such as alkyl, cycloalkyl, aryl, and aralkyl, either of which can be substituted with a halogen, alkyl, or alkoxy group, or two R ⁹ groups can be joined to form a ring with a phosphorus atom, and wherein R ¹⁰ is a hydrocarbyl group, a S-, O-, or N-containing five or six membered heterocyclic group, or a-Z-C (=o) -P (=o) - (R ⁹)₂ group, wherein Z represents a divalent hydrocarbyl group such as an alkylene or a phenylene having 2 to 6 carbon atoms.

Preferred acylphosphine oxides are those wherein the R ⁹ and R ¹⁰ groups are phenyl or lower alkyl or lower alkoxy substituted phenyl. By "lower alkyl" and "lower alkoxy" is meant such groups having from 1 to 4 carbon atoms. Examples can also be found in, for example, US 4,737,593.

Examples include bis- (2, 6-dichlorobenzoyl) phenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 5-dimethylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-ethoxy-phenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-biphenylylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-propylphenylphosphine oxide, bis- (2, 6-dichlorobenzoyl) -2-naphthyl-phosphine oxide, bis- (2, 6-dichlorobenzoyl) -1-naphthyl phosphine oxide, bis- (2, 6-dichloro-benzoyl) -4-chlorophenyl phosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 4-dimethoxyphenyl-phosphine oxide, bis- (2, 6-dichlorobenzoyl) decylphosphine oxide, bis- (2, 6-dichloro-benzoyl) -4-octylphenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 5-dimethyl-phenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2, 6-dimethoxybenzoyl-phosphine oxide, bis- (2, 6-dimethylbenzoyl) -2, 6-dimethylbenzoyl-phosphine oxide, bis- (2, 6-dichlorobenzoyl) -4-dimethylbenzoyl-phosphine oxide, bis- (2, 6-dichlorobenzoyl) -2, 5-dimethylbenzyl phosphine oxide, bis- (2, 6-dimethylbenzoyl) -2, 5-dimethylbenzyl phosphine oxide Bis- (2, 6-dichloro-3, 4, 5-trimethoxybenzoyl) -4-ethoxyphenyl phosphine oxide, bis- (2-methyl-1-naphthoyl) -2, 5-dimethylphenyl phosphine oxide, bis- (2-methyl-1-naphthoyl) phenyl phosphine oxide, bis- (2-methyl-1-naphthoyl) -4-biphenylphosphine oxide, bis- (2-methyl-1-naphthoyl) -4-ethoxyphenyl phosphine oxide, bis- (2-methyl-1-naphthoyl) -2-naphthyl phosphine oxide, bis- (2-methyl-1-naphthoyl) -4-propylphenyl phosphine oxide, bis- (2-methyl-1-naphthoyl) -2, 5-dimethylphosphine oxide, bis- (2-methoxy-1-naphthoyl) -4-ethoxyphenyl phosphine oxide, bis- (2-methoxy-1-naphthoyl) -4-biphenylphosphine oxide, bis- (2-methoxy-1-naphthoyl) -2-naphtyl phosphine oxide and bis- (2-chloro-1-naphthoyl) -2, 5-dimethylphenyl phosphine oxide.

The tertiary amine reducing agent may be used in combination with the acyl phosphine oxide. Exemplary tertiary amines useful in the present invention include ethyl 4- (N, N-dimethyl-amino) benzoate and N, N-dimethylaminoethyl methacrylate.

Commercially available phosphine oxide photoinitiators capable of free radical initiation when irradiated at wavelengths from greater than 400nm to 1,200nm include a 25:75 by weight mixture of bis (2, 6-dimethoxybenzoyl) -2, 4-trimethylpentylphosphine oxide with 2-hydroxy-2-methyl-1-phenylpropan-1-one (previously known as Irgacure ^™ 1700, ciba), 2-benzyl-2- (N, N-dimethylamino) -1- (4-morpholinophenyl) -1-butanone (previously known as Irgacure ^™ 369, vapor), bis (. Eta.5-2, 4-cyclopentan-1-yl) -bis (2, 6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium (previously known as Irgacure ^™ 784 DC, vapor), 1:1 by weight of a mixture of bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one (previously known as Darocur ^™ 4265, vapor), ethyl-2, 4, 6-trimethylbenzyl phenylphosphine oxide (previously known as Lucirin ^™ LR8893X, basf), and bis (2, 4, 6-trimethylbenzoyl) -phenylphosphine oxide (previously known as Irgacure ^™ 819, basf).

Another radical initiator system that may alternatively be used includes the class of ionic dye counter ion complexing initiators that contain borate anions and complementary cationic dyes.

Borate photoinitiators are described, for example, in U.S. Pat. No. 4,772,530 (Gottschalk et al), U.S. Pat. No. 4,954,414 (Adair et al), U.S. Pat. No. 4,874,450 (Gottschalk), U.S. Pat. No. 5,5,055,372 (Shanklin et al) and U.S. Pat. No. 3, 5,057,393 (Shanklin et al).

Borate anions useful in these photoinitiators may generally have the formula R ¹R²R³R⁴B^-, where R ¹、R²、R³ and R ⁴ may independently be alkyl, aryl, alkylaryl, allyl, aralkyl, alkenyl, alkynyl, cycloaliphatic, and saturated or unsaturated heterocyclic groups. Preferably, R ²、R³ and R ⁴ are aryl groups and more preferably phenyl groups, and R ¹ is an alkyl group and more preferably a secondary alkyl group.

The cationic counterion may be a cationic dye, a quaternary ammonium group, a transition metal coordination complex, or the like. The cationic dyes used as counter ions may be cationic methine, polymethine, triarylmethine, indoline, thiazine, xanthene, oxazine or acridine dyes. More specifically, the dye may be a cationic cyanine, carbocyanine, hemicyanine, rhodamine, and azomethine dye. Specific examples of useful cationic dyes include methylene blue, safranin O and malachite green. The quaternary ammonium groups used as counter ions may be trimethylhexadecyl ammonium, hexadecyl pyridine and tetramethyl ammonium. Other organophilic cations may include pyridinium, phosphonium, and sulfonium.

Photoactive transition metal coordination complexes that may be used include complexes of cobalt, ruthenium, osmium, zinc, iron, and iridium with ligands such as pyridine, 2' -bipyridine, 4' -dimethyl-2, 2' -bipyridine, 1, 10-phenanthroline, 3,4,7, 8-tetramethyl-phenanthroline, 2,4, 6-tris (2-pyridyl-s-triazine), and related ligands.

In the alternative, heat may be used to initiate the hardening or polymerization of the free radical reactive groups.

Examples of heat sources suitable for use in the dental materials of the present invention include induction, convection, and radiation. The heat source should be capable of producing a temperature of at least 40 ℃ to 15 ℃ under normal conditions or at elevated pressure.

Thermal curing procedures are sometimes preferred for initiating polymerization of materials that occur outside of the oral environment, for example, when the composition is used to produce an abrasive blank or in a post-curing step of an article obtained by processing the composition into a resin in a layup manufacturing process.

The components of the photoinitiator system are typically present in an amount of at least 0.1 wt%, or 0.2 wt%, or 0.3 wt%, up to 4 wt%, or 3 wt%, or 2 wt%, in the range of 0.1 wt% to 4 wt%, or 0.2 wt% to 3 wt%, or 0.3 wt% to 2 wt%, with respect to the dental composition.

Alternatively or additionally, the dental composition may be cured by using a redox initiator system.

Initiators that rely on redox reactions are commonly referred to as "self-curing catalysts" or "dark-curing catalysts". To avoid premature curing of the dental composition, the two main components of this system (oxidizing agent and reducing agent) should be kept separate during storage of the dental composition.

As the oxidizing component, a peroxy component such as a peroxide is generally used. Organic peroxides that may be used include diperoxides and hydroperoxides.

According to one embodiment, the organic peroxide is a diperoxide, preferably a diperoxide comprising a moiety R ₁-O-O-R₂-O-O-R₃, wherein R ₁ and R ₃ are independently selected from H, alkyl (e.g., C ₁ to C ₆), branched alkyl (e.g., C ₁ to C ₆), cycloalkyl (e.g., C ₅ to C ₁₀), alkylaryl (e.g., C ₇ to C ₁₂), or aryl (e.g., C ₆ to C ₁₀), and R ₂ is selected from alkyl (e.g., C ₁ to C ₆) or branched alkyl (e.g., C ₁ to C ₆).

Examples of suitable organic diperoxides include 2, 2-di- (t-butylperoxy) butane and 2, 5-dimethyl-2, 5-di- (t-butylperoxy) hexane, and mixtures thereof.

According to another embodiment, the organic peroxide is a hydroperoxide, in particular a hydroperoxide comprising a moiety

R-O-O-H

Wherein R is (e.g., C ₁ to C ₂₀) alkyl, (e.g., C ₃ to C ₂₀) branched alkyl, (e.g., C ₆ to C ₁₂) cycloalkyl, (e.g., C ₇ to C ₂₀), alkylaryl (e.g., C ₆ to C ₁₂), or aryl (e.g., C ₆ to C ₁₂).

Examples of suitable organic hydroperoxides include t-butyl hydroperoxide, t-amyl hydroperoxide, p-diisopropylbenzene hydroperoxide, cumene hydroperoxide, pinane hydroperoxide, p-methane hydroperoxide and 1, 3-tetramethylbutyl hydroperoxide, and mixtures thereof.

The use of hydroperoxides is sometimes preferred, especially for formulating self-adhesive compositions.

Other peroxides that may be used are ketone peroxides, diacyl peroxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxydicarbonates.

Examples of ketone peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, methyl cyclohexanone peroxide, and cyclohexanone peroxide.

Examples of peroxyesters include alpha-cumyl peroxyneodecanoate, t-butyl peroxypivalate, t-butyl peroxyneodecanoate, 2, 4-trimethylpentyl peroxy2-ethylhexanoate, t-amyl peroxy2-ethylhexanoate, t-butyl peroxy2-ethylhexanoate, di-t-butyl peroxyisophthalic acid, di-t-butyl peroxyhexahydroterephthalate, t-butyl peroxy3, 3, 5-Trimethylhexanoate (TBPIN), t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxymaleate.

Examples of peroxydicarbonates include di-3-methoxy peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate, diisopropyl-1-peroxy-dicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl-peroxydicarbonate, and diallyl peroxydicarbonate.

Examples of diacyl peroxides include acetyl peroxide, benzoyl peroxide, decanoyl peroxide, 3, 5-trimethylhexanoyl peroxide, 2, 4-dichlorobenzoyl peroxide, and lauroyl peroxide.

Examples of dialkyl peroxides include di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, 2, 5-dimethyl-2, 5-di (tert-butylperoxy) hexane, 1, 3-bis (tert-butylperoxyisopropyl) benzene, and 2, 5-dimethyl-2, 5-di (tert-butylperoxy) -3-hexane.

Examples of peroxyketals include 1, 1-bis (t-butylperoxy) -3, 5-trimethylcyclohexane, 1-bis (t-butylperoxy) cyclohexane, 2-bis (t-butylperoxy) butane, 2-bis (t-butylperoxy) octane, and 4, 4-bis (t-butylperoxy) pentanoate-n-butyl ester.

The peroxygen component, if present, is typically present in an amount of 0.1 to 5% by weight or 0.25 to 4% by weight of the dental composition.

In addition to the peroxide component, other oxidizing components may be present, such as a persulfate component, in particular a water-soluble persulfate component.

The persulfates that can be used can be characterized by the formula D ₂S₂O₈, wherein D is selected from Li, na, K, NH ₄、NR₄, wherein R is selected from H and CH ₃. Examples of persulfates that may be used include Na₂S₂O₈、K₂S₂O₈、(NH₄)₂S₂O₈ and mixtures thereof.

If a persulfate component is present, it is typically present in an amount of from 0.1 to 5 wt% or from 0.25 to 4 wt%.

As reducing agent, barbituric acid or thiobarbituric acid components, in particular the corresponding salts thereof, can be used. Suitable barbituric acid components can be characterized by the following formula:

Wherein R1, R2 and R3 are independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl, X is oxygen or sulfur, Y is a metal cation or an organic cation.

The salt may comprise a metal cation or an inorganic cation. Suitable metal cations include any metal M capable of providing a stabilizing cation M ⁺、M²⁺ or M ³⁺. Some possible inorganic cations include Li, na, K, mg, ca, sr, ba, al, fe, cu, zn or La cations.

Examples of suitable barbituric acid components or thiobarbituric acid components include barbituric acid, thiobarbituric acid, 1,3, 5-trimethylbarbituric acid, 1-phenyl-5-benzylbarbituric acid, 1-benzyl-5-phenylbarbituric acid, 1, 3-dimethylbarbituric acid, 1, 3-dimethyl-5-phenylbarbituric acid, 1-cyclohexyl-5-ethylbarbituric acid, 5-laurylpbarbituric acid, 5-butylbarbituric acid, 5-allylbarbituric acid, 5-phenylthiobarbituric acid, 1, 3-dimethylthiobarbituric acid, trichlorobarbituric acid, 5-nitrobarbituric acid, 5-aminopbarbituric acid, and 5-hydroxy barbituric acid.

An exemplary salt is the calcium salt of 1-benzyl-5-phenyl-barbituric acid. Another example of a suitable barbiturate is the sodium salt of 1-benzyl-5-phenyl-barbituric acid. A possible salt is the calcium salt of 5-phenyl-thiobarbituric acid.

The salt may also contain an organic cation. Suitable possible organic cations include cations of amines, such as ammonium cations or alkylammonium cations. One example is the triethanolamine salt of 1-benzyl-5-phenyl-barbituric acid.

If barbituric acid or thiobarbituric acid components are present, they are typically present in an amount of 0.1 to 3 or 0.5 to 2% by weight of the dental composition.

Other reducing agents that may be used include aromatic sulfinate or thiourea components.

Suitable sulfinic acid components may have the formula

R¹SOO-R²,

Wherein R ¹ is alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl radical, and R ² = H, a metal (such as lithium, sodium or potassium), or is an alkyl, substituted alkyl, alkenyl, cycloalkyl, substituted cycloalkyl, arylalkyl, aryl or substituted aryl radical.

If one of the radicals R ¹ or R ² is unsubstituted alkyl, this radical may be straight-chain or branched and may contain, for example, from 1 to 18 carbon atoms, preferably from 1 to 10, in particular from 1 to 6 carbon atoms. Examples of low molecular weight alkyl radicals are methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, isobutyl, n-pentyl and isopentyl.

If one of the radicals R ¹ or R ² is a substituted alkyl radical, the alkyl portion of that radical will typically have the number of carbon atoms indicated above for the unsubstituted alkyl group. If one of the radicals R ¹ or R ² is an alkoxyalkyl or alkoxycarbonylalkyl radical, the alkoxy radical contains, for example, from 1 to 5 carbon atoms and is preferably methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl or isopentyl. If one of the radicals R ¹ or R ² is a haloalkyl group, then the halo moiety is understood to be fluorine, chlorine, bromine or iodine.

If one of the radicals R ¹ or R ² is alkenyl, it is generally a C ₃ to C ₅ alkenyl radical, in particular allyl. If one of the radicals R ¹ or R ² is unsubstituted cycloalkyl, it is typically a C ₄ to C ₇ cycloalkyl radical such as cyclopentyl or cyclohexyl. If one of the radicals R ¹ or R ² is a substituted cycloalkyl radical, it is typically one of the cycloalkyl radicals mentioned above, where the substituent on the cycloalkyl radical may be, for example, C ₁ to C ₄ alkyl (such as methyl, ethyl, propyl, n-butyl or isobutyl), fluorine, chlorine, bromine, iodine or C ₁ to C ₄ alkoxy, especially methoxy. If one of the radicals R ¹ or R ² is aryl or aralkyl, it is typically phenyl or naphthyl as aryl. Preferred arylalkyl radicals include benzyl and phenylethyl.

R ¹ or R ² can also be substituted aryl radicals, if desired. In this case, phenyl and naphthyl are preferred, and as ring substituents, C ₁ to C ₄ alkyl, especially methyl, halogen or C ₁ to C ₄ alkoxy, especially methoxy.

In particular, it was found that benzenesulfonic acid, sodium benzenesulfonate dihydrate, sodium toluenesulfonate, formamidine sulfinic acid, sodium salt of hydroxymethanesulfinic acid, sodium salt of 2, 5-dichlorobenzenesulfinic acid, 3-acetamido-4-methoxybenzenesulfonic acid, with sodium toluenesulfonate or sodium benzenesulfonate and hydrates thereof being sometimes preferred.

If present, the sulfinic acid component is typically present in an amount of 0.1 to 3% by weight or 0.5 to 2% by weight of the dental cement composition.

Suitable thiourea components include 1-ethyl-2-thiourea, tetraethylthiourea, tetramethylthiourea, 1-dibutylthiourea and 1, 3-dibutylthiourea and mixtures thereof.

If desired, the dental cement composition may contain a combination or mixture of different reducing agents, including a combination of barbituric acid and sulfinic acid components.

In addition to the above components, the redox initiator system may also comprise an activator.

Suitable activators include aromatic tertiary amines such as N, N-bis (hydroxyalkyl) -3, 5-dimethylaniline (e.g. as described in US 3,541,068) and N, N-bis (hydroxyalkyl) -3, 5-di-tert-butylaniline, in particular N, N-bis ([ beta ] -oxybutyl) -3, 5-di-tert-butylaniline and N, N-bis (hydroxyalkyl) -3,4, 5-trimethylaniline.

If desired and for acceleration, the polymerization can also be carried out in the presence of transition metal components. Suitable transition metal components include organic and/or inorganic salts of vanadium, chromium, manganese, iron, cobalt, nickel and/or copper, with copper, iron and vanadium being sometimes preferred.

According to one embodiment, the transition metal component is a copper-containing component. The oxidation stage of copper in the copper-containing component is preferably +1 or +2.

Typical examples of copper components that may be used include copper salts and complexes, including copper acetate, copper chloride, copper benzoate, copper acetylacetonate, copper naphthenate, copper carboxylate, bis (1-phenylpentane-1, 3-dione) copper complex (cupferron salt (copper procetonate)), copper ethylhexanoate, copper salicylate, copper complexes with thiourea, ethylenediamine tetraacetic acid, and/or mixtures thereof. The copper compound may be used in hydrated or anhydrous form.

Copper (II) acetate, bis (1-phenylpentane-1, 3-dione) copper complex (cupferroprotein) and copper ethylhexanoate are sometimes particularly preferred.

According to one embodiment, the transition metal component is an iron-containing component. The oxidation stage of iron in the iron-containing component is preferably +2 or +3.

Typical examples of iron-containing components that may be used include salts and complexes of iron, including iron (III) sulfate, iron (III) chloride, iron (III) carboxylate, iron naphthenate, iron (III) acetylacetonate, including hydrates of these salts.

According to one embodiment, the transition metal component is a vanadium-containing component. The oxidation stage of vanadium in the vanadium-containing component is preferably +4 or +5.

Typical examples of vanadium components that may be used include salts and complexes of vanadium, including vanadyl acetylacetonate, vanadyl stearate, vanadyl naphthenate, vanadyl benzoylacetonate, vanadyl oxalate, bis (maltosyl) vanadyl (IV), oxo-bis (1-phenyl-1, 3-butanedione) vanadyl (V), triisopropoxyvanadyl (V), ammonium metavanadate (V), sodium metavanadate (V), vanadyl pentoxide (V), vanadyl (IV), and vanadyl sulfate (IV), and mixtures thereof, with vanadyl acetylacetonate, and bis (maltosyl) vanadyl (IV) being sometimes preferred.

Suitable redox initiator systems are also described in US 2003/008967 A1 (Hecht et al), US 2004/097613 A1 (Hecht et al), US 2019/000721 A1 (Ludsteck et al). The contents of these references are incorporated herein by reference.

The composition may also contain suitable adjuvants or additives such as surfactants, rheology modifiers, retarders, stabilizers, pigments, dyes, photobleachable colorants, fluoride releasing agents, solvents, and other ingredients known to those skilled in the art.

Additional surfactants include polyethylene glycol modified silicones (e.g., silwet ^™ type surfactants available from michigan (Momentive)) and polyethylene glycol modified carbosilanes (e.g., as described in US 5,750,589 (Zech et al)).

Additional rheology modifiers include surface modified fumed silica, organophilic phyllosilicates, modified ureas, and polyhydroxycarboxylic acid amides as described above (e.g., model Rheobyk ^™ available from Weisselbik chemical (Byk-Chemie, wesel, germany)), dibenzylidene sorbitol, and diamides (e.g., model Thixatrol ^™ available from Ewensha sea Minsis (Eementis, east Windsor, new Jersey, USA), all of which are described above.

The retarder which may be added includes 1, 2-diphenylethylene and its derivatives.

Stabilizers which may be used include, inter alia, free-radical scavengers such as substituted and/or unsubstituted hydroxyaromatic compounds (e.g., butylated Hydroxytoluene (BHT), hydroquinone Monomethyl Ether (MEHQ), 3, 5-di-tert-butyl-4-hydroxy-anisole (2, 6-di-tert-butyl-4-ethoxyphenol), 2, 6-di-tert-butyl-4- (dimethylamino) methylphenol or 2, 5-di-tert-butylhydroquinone, 2- (2 ' -hydroxy-5 ' -methylphenyl) -2H-benzotriazole, 2- (2 ' -hydroxy-5 ' -tert-octylphenyl) -2H-benzotriazole, 2-hydroxy-4-methoxybenzophenone (UV-9), 2- (2 ' -hydroxy-4 ',6' -di-tert-pentylphenyl) -2H-benzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, 2- (2 ' -hydroxy-5 ' -methacryloyloxyethylphenyl) -2H-benzotriazole, phenothiazine and amine light stabilizers (HALS).

Pigments and/or dyes that may be used include titanium dioxide or zinc sulfide (lithopone), iron oxide red 3395, bayferrox ^™, 920, Z yellow, neazopon ^™ blue 807 (copper phthalocyanine based dye), or Helio ^™ Fast yellow ER. These additives can be used for the individual coloration of the composition.

Examples of photobleachable colorants include rose bengal, methylene violet, methylene blue, fluorescein, eosin yellow, eosin Y, ethyl eosin, eosin blue, eosin B, erythrosin yellow blends, toluidine blue, 4',5' -dibromofluorescein, and blends thereof. Other examples of photobleachable colorants can be found in US 6,444,725 (Trom et al).

Examples of fluoride release agents include naturally occurring or synthetic fluoride minerals. These fluoride sources may optionally be treated with a surface treatment agent.

Solvents which may be present include linear, branched or cyclic saturated or unsaturated alcohols, ketones, esters, ethers or mixtures of two or more solvents of the type described having from 2 to 10C atoms. Preferred alcohol solvents include methanol, ethanol, isopropanol, and n-propanol. Other suitable organic solvents are THF, acetone, methyl ethyl ketone, cyclohexanol, toluene, alkanes and alkyl acetates, especially ethyl acetate.

These additives need not be present and thus may not be present at all. However, if present, they are generally present in amounts that are not detrimental to the intended purpose.

The additives are typically present in an amount of at least 0wt%, or 0.01 wt%, or 0.1 wt%, up to 20 wt%, or 15 wt%, or 10 wt%, in the range of 0wt% to 20 wt%, or 0.01 wt% to 15 wt%, or 0.1 wt% to 10 wt%, with respect to the dental composition.

The dental composition comprises, consists essentially of, or consists of:

a. in particular in an amount of 40 to 80% by weight,

B. In particular in an amount of from 5 to 50% by weight,

C. in particular in an amount of from 0.1 to 5% by weight, of an initiator system suitable for curing the curable component,

D. in particular in an amount of 0 to 10% by weight,

Weight% relative to the weight of the dental composition.

The dental compositions described herein are typically prepared by combining or mixing the respective components (i.e., the polymerizable component of the resin matrix, the filler, and the initiator component) with other optional components, such as additives. Typically, the resin matrix is provided first, and then the filler is added.

If desired, a high speed mixer may be used. Depending on the components to be mixed, the mixing is carried out under light-protected conditions. Mixing also includes kneading. If desired, a vacuum may be applied during or at the end of mixing to remove air introduced during mixing or kneading.

The dental compositions described herein are generally for use in a method of repairing a tooth in the oral cavity of a mammal, wherein the dental composition is as described herein, and wherein the method comprises the steps of:

a) Contacting the dental composition with the surface of the tooth to be repaired,

B) The dental composition is cured by application of radiation.

More particularly, the method may comprise the steps of:

a) The dental composition is applied to the surface of a hard dental tissue, which may be an etched surface (e.g., with phosphoric acid) or a non-etched surface if desired,

B) The dental composition is preferably optionally dispersed to a film using an air stream,

C) Radiation-curable dental compositions.

For the curing step, dental curing light is generally used. The radiation typically has a wavelength in the range of 400nm to 800nm and is applied for a period of time in the range of 5 seconds to 1 minute.

Dental compositions are particularly useful in the dental and orthodontic fields. The dental composition may be used as or for the production of dental restorations.

Examples of dental restorations include direct restorative materials (e.g., anterior and posterior restorations), prostheses, veneers, artificial crowns, artificial teeth, dentures, and the like.

As used herein, the term "prosthesis" refers to a composite that is shaped and polymerized for its end use (e.g., as a crown, bridge, veneer, inlay, onlay, etc.) prior to placement adjacent a tooth.

When the dental material is applied to a tooth, the tooth may optionally be pretreated with a primer such as dentin or enamel adhesive by methods known to those skilled in the art.

In particular, the dental composition may be used as a composite filling material, a cavity liner, or a fixing material for orthodontic appliances.

The term "composite filling material" refers to a filled dental composition. Dental composites are commonly used to repair defective tooth structures in the mouth of a patient.

"Cavitating agent" refers to a composition for protecting the dental pulp prior to application of the composite filling material or dental restoration.

In a preferred aspect, the dental material is a low viscosity dental filling material.

Another aspect of the invention relates to the use of a surface treated filler as described herein for reducing the viscosity of a dental composition comprising a curable component and a filler in an amount of 40 to 80wt% relative to the weight of the dental composition.

The surface treated filler is particularly useful for producing hardenable dental compositions having a filler content of 40 to 80 weight percent and 5Pa at 25 ℃ and a shear rate of 0.01s ^-1 if no rheology modifier is presentS to 1,500PaS viscosity.

In another aspect, the invention relates to the following embodiments:

Embodiment 1

A dental composition comprising a dental compound, the dental composition comprises, consists essentially of, or consists of:

in an amount of 40 to 80% by weight of a surface-treated filler,

A curable component in an amount of from 5 to 50 weight percent, the curable component selected from the group consisting of a polymerizable component comprising an acidic moiety, a polymerizable component not comprising an acidic moiety, and mixtures thereof,

An initiator system suitable for curing the curable component in an amount of 0.1 to 5% by weight, comprising a photoinitiator system and/or a redox initiator system,

An additive in an amount of 0 to 10 wt%,

Weight% relative to the weight of the dental composition,

The surface treatment is characterized by the following features:

Comprising only one (meth) acrylate moiety,

Comprising at least one trimethoxysilane or triethoxysilane moiety,

Comprising only one urethane moiety,

Comprising one linear alkylene moiety AM1 linking said (meth) acrylate moiety to said urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12C atoms,

Comprising one linear alkylene moiety AM2 linking said at least one trimethoxysilane or triethoxysilane moiety to said carbamate moiety, said linear alkylene moiety AM2 comprising from 1 to 4C atoms.

Embodiment 2

A surface treated filler in an amount of 40 to 80 weight percent, the filler particles selected from the group consisting of non-aggregated, non-agglomerated nano-sized particles of SiO ₂、ZrO₂ or mixtures thereof, aggregated nano-sized particles of SiO ₂、ZrO₂ or mixtures thereof, agglomerated nano-sized particles of SiO ₂、ZrO₂、Al₂O₃ or mixtures thereof, non-acid reactive particles of glass, silica, metal oxides or mixtures thereof, acid reactive particles of glass, metal oxides and hydroxides or mixtures thereof,

An additive in an amount of 0 to 10 wt%,

Weight% relative to the weight of the dental composition,

The surface treatment is characterized by the following features:

Comprising only one (meth) acrylate moiety,

Comprising at least one trimethoxysilane or triethoxysilane moiety,

Comprising only one urethane moiety,

Embodiment 3

in an amount of 40 to 80% by weight of a surface-treated filler,

An additive in an amount of 0 to 10 wt%,

Weight% relative to the weight of the dental composition,

The surface treatment agent is characterized by the formula:

H₂C=CHR¹-CO-O-(CH₂)_n-X-CO-Y-(CH₂)_m-Si(R²)_o(R³)_3-o

Embodiment 4

A surface treated filler in an amount of 40 to 80 wt%, the filler particles being selected from the group consisting of aggregated nano-sized particles of SiO ₂、ZrO₂ or mixtures thereof, agglomerated nano-sized particles of SiO ₂、ZrO₂、Al₂O₃ or mixtures thereof,

An additive in an amount of 0 to 10 wt%,

Weight% relative to the weight of the dental composition,

The surface treatment is characterized by the following features:

Comprising only one (meth) acrylate moiety,

Comprising at least one trimethoxysilane or triethoxysilane moiety,

Comprising only one urethane moiety,

The dental compositions described herein are generally free of bisphenol a-glycidyl methacrylate (Bis-GMA), in particular in an amount of 1% by weight or more relative to the weight of the dental composition. Thus, such components are typically not present and/or have not been added completely.

Dental compositions are typically provided to practitioners under hygienic conditions. During storage, the compositions are typically packaged in suitable packaging and/or delivery devices.

One possibility to achieve this includes packaging or storing the composition in a sealed container. Suitable containers may have a front end and a rear end, a piston movable in the container, and a nozzle or cannula for delivering or dispensing the composition located in the container. The container typically has only one compartment or reservoir. The volume of the container is typically in the range of 0.1ml to 100ml, or 0.5ml to 50ml, or 1ml to 30 ml.

Suitable disposable containers may have a volume in the range of 0.05ml to 1 ml. This is the volume typically required for a single administration protocol. Such containers are typically used only once (e.g., disposable packages).

The composition may be dispensed from the container by moving the piston in the direction of the nozzle. The piston can be moved manually or by means of an applicator or applicator designed to receive the container (e.g. an applicator having a caulking gun design).

Examples of containers that may be used include a squeeze bag, a syringe, and a coiled tube.

The bladder generally has a cylindrical housing with front and rear ends and a nozzle. The rear end of the housing is typically sealed by a movable piston. Typically, an applicator having a movable plunger (e.g., an applicator having the shape of a caulking gun) is used to dispense the dental composition from the capsule or container.

Examples of suitable bladders or containers are described in US 5,624,260 (Wilcox et al), EP 1 340 A1 (Centrix), US 2007/0172789 A1 (Mueller et al) and US 5,865,803 (Major). Other suitable containers are exemplified in US 5,927,562 (Hammen et al) and US 2011/151403 A1 (Pauser et al).

It would be advantageous if the container used included a nozzle having a shape and size, which allowed for easy and safe application of the composition to soft dental tissue surrounding the tooth to be restored, also in the vicinity of the interdental area.

The smaller the diameter of the nozzle, the easier the nozzle can be placed into the area between two teeth. However, small diameter nozzles may result in an increase in the extrusion force required to dispense the composition out of the device. Thus, not all sleeve sizes and diameters are equally suitable. Devices having nozzles or cannulas with outer diameters in the range of 0.6mm to 1.3mm and inner diameters in the range of 0.2mm to 0.9mm have been found to be particularly useful.

Flowable dental composites are typically stored in a packaging material having the shape of a syringe.

The packaging device may further comprise two compartments, wherein each compartment is equipped with a nozzle for delivering the composition or part stored therein. Once delivered in sufficient portions, the portions may be manually mixed on a mixing plate.

Packaging devices having two compartments are particularly useful for storing and delivering two-part compositions, i.e., compositions that need to be kept separate prior to use to avoid undesired polymerization. The two-part composition is typically cured by a redox initiator system in which the oxidant-containing part is kept separate from the reducing agent-containing part.

The packaging device may have an interface for receiving the static mixing tip. The mixing tip is used to mix the respective compositions.

The packaging device generally comprises two housings or compartments having a front end with a nozzle and a rear end, at least one piston movable in the housing or compartment.

Cartridges that can be used are also described, for example, in US 2007/0090079 A1 or US 5,918,772. Some cartridges that may be used are commercially available, for example, from SulzerMixpac company (SulzerMixpac company) (Switzerland).

Static mixing tips that may be used are described, for example, in US 2006/0187752 A1 or US 5944419, the disclosures of which are incorporated by reference. The mixing tips that can be used are also commercially available from Sulzer Mixpac (Switzerland).

Other suitable storage devices are described, for example, in WO 2010/123800 A1 (3M), WO 2005/016783 A1 (3M), WO 2007/104037 A1 (3M), WO 2009/061884 A1 (3M), in particular the device shown in fig. 14 of WO 2009/061884 A1 (3M) or WO 2015/073246 A1 (3M), in particular the device shown in fig. 1 of WO 2015/07346 A1. These storage means have the shape of a syringe.

The invention also relates to a kit comprising the dental composition described herein and, alone or in combination, a dental adhesive, a dental curing light, and an applicator.

Dental adhesives are typically relatively low viscosity (e.g., 0.01Pa at 25℃)S to 3PaS) acidic dental composition. Dental adhesives interact directly with the enamel or dentin surface of a tooth. Dental adhesives are typically one-part compositions, are radiation curable, and comprise an ethylenically unsaturated component having an acidic moiety, an ethylenically unsaturated component having no acidic moiety, water, a sensitizer, a reducing agent, and an additive.

Examples of dental adhesives are described in US 2020/0069532 A1 (THALACKER et al) and US 2017/0065495 A1 (Eckert et al). Dental adhesives are also commercially available, for example 3M ^™ Scotchbond^™ Universal (3M Oral Care company (3M Oral Care)).

Suitable dental curing lights are described in U.S. Pat. No. 10,758,126 B2 (GELDMACHER et al) or U.S. Pat. No. 10,231,810 B2 (Gramann et al). Dental curing lights are also commercially available, such as 3M ^™ Elipar^™ S10 or 3M ^™ Elipar^™ DeepCure S LED curing lights (3M oral care).

Suitable applicators include, for example, brushes, scrapers, syringes, and other suitable devices known to those skilled in the art.

The entire disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. The above specification, examples and data provide a description of the manufacture and use of the compositions of the invention and the methods of the invention. The present invention is not limited to the embodiments disclosed herein. Those skilled in the art will appreciate that many alternative embodiments of the invention can be made without departing from the spirit and scope of the invention.

The following examples are given to illustrate the invention.

Examples

All parts and percentages are by weight, all water is deionized water, and all molecular weights are weight average molecular weights, unless otherwise indicated. Furthermore, all experiments were carried out under ambient conditions (23 ℃ C.; 1013 mbar) unless otherwise indicated.

Method of

Viscosity of the mixture

Viscosity measurements were made on a rheometer equipped with a plate-plate system (d=15 mm or 20 mm) using a 0.2mm gap at 25 ℃ and gradual shear from 100/s to 0.008/s over 1 minute.

Particle size (for micron-sized particles)

If desired, the particle size distribution, including the particle size per volume (d 50), can be determined by laser diffraction using a Mastersizer 2000 (Malvern) particle size detection device using the Fraunhofer approximation. During measurement, ultrasound is typically used to accurately disperse the sample. For water-insoluble particles, water is generally used as a dispersant.

Particle size (applicable to nanosize particles)

If desired, particle size measurements can be made using a light scattering particle size analyzer (available under the trade designation "ZETA SIZER-Nano Series, model ZEN3600" from Markov instruments Inc. (Malvern Instruments Inc., westborough, mass.) equipped with a red laser having a wavelength of 633 nm. Each sample was analyzed in a polystyrene sample cuvette of one square centimeter. Sample 1:100 is diluted, for example 1g sample is added to 100g deionized water and mixed. The sample cuvette was filled with about 1 gram of diluted sample. The sample cuvette was then placed in the instrument and equilibrated at 25 ℃. The instrument parameters were set as follows, dispersant refractive index 1.330, dispersant viscosity 0.8872mPaS, material refractive index 1.43, and material absorption value 0.00 units. An automatic sizing program is then run. The instrument automatically adjusts the laser beam position and attenuator settings to obtain the best particle size measurement.

The light scattering particle sizer irradiates the sample with laser light and analyzes the intensity fluctuation of light scattered from the particles at 173 degrees. The instrument may use a Photon Correlation Spectroscopy (PCS) method to calculate particle size. The PCS uses the fluctuating light intensity to measure brownian motion of particles in a liquid. The particle size is then calculated as the diameter of the sphere moving at the measured speed.

The intensity of light scattered by a particle is proportional to the sixth power of the particle size. The Z-average size or cumulative average is the average calculated from the intensity distribution and this calculation is based on the assumption that the particles are unimodal, monodisperse and spherical. The correlation function calculated from the fluctuating light intensity is the intensity distribution and its average. The average value of the intensity distribution is calculated based on the assumption that the particles are spherical. The Z-average size and intensity distribution average is more sensitive to larger particles than to smaller particles.

The volume distribution gives the percentage of the total volume of particles corresponding to particles in the given size range. The volume average size is the size of the particles corresponding to the average value of the volume distribution. Since the volume of the particles is proportional to the diameter to the third power, the sensitivity of this distribution to larger particles is lower than the Z-average size. Thus, the volume average is typically a smaller value than the Z average size. Within the scope of this document, the Z-average size is referred to as the "average particle size".

PH value of

If desired, the pH can be determined by dispersing 1.0g of the material to be tested in 10ml of deionized water and stirring for about 5 minutes. The calibrated pH electrode was immersed in the suspension and the pH was determined during stirring.

Elemental composition

If desired, the elemental composition can be determined by X-ray fluorescence spectroscopy (XRF), for example using ZSX Primus II from Japanese Physics (Rigaku, japan).

Flexural Strength (FS)

If desired, flexural strength can be achieved by using a size of 22The 25mm test specimens were determined by a three-point flexural strength test according to ISO 4049:2019. Flexural strength is given in MPa.

Flexural Modulus (FM)

If desired, the flexural modulus can be measured as the slope of the linear elastic portion of the stress-strain curve along with the flexural strength test using a universal tester (e.g., zwick). Flexural modulus is given in GPa.

Material

TABLE 1

Synthesis of 11- (3-trimethoxysilylpropyl carbamoyloxy) undecyl 2-methylprop-2-enoate

(C11 methoxy)

11-Hydroxyundecyl 2-methylprop-2-enoate (35.0 g,137 mmol) was charged to a 3-neck RBF 250mL equipped with an internal thermometer and magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (29.0 g,141 mmol) was added and the mixture was stirred at 60℃for 48 hours. Infrared absorption analysis indicated complete consumption of isocyanate.

Synthesis of 9- (3-trimethoxysilylpropyl carbamoyloxy) nonyl 2-methylprop-2-enoate

(C9 methoxy)

9-Hydroxy-nonyl 2-methylprop-2-enoate (35.0 g,153 mmol) was charged to a 3-neck 250mL RBF equipped with an internal thermometer and magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (32.5 g,158 mmol) was added and the mixture was stirred at 60℃for 48 hours. Infrared absorption analysis indicated complete consumption of isocyanate.

Synthesis of 6- (3-trimethoxysilylpropyl carbamoyloxy) hexyl 2-methylprop-2-enoate

(C6 methoxy)

6-Hydroxyhexyl 2-methylprop-2-enoate (35.0 g,188 mmol) was charged to a 3-neck 250mL RBF equipped with an internal thermometer and magnetic stirrer, and 3-isocyanatopropyl-trimethoxysilane (40.0 g,195 mmol) was added and the mixture was stirred at 60℃for 48 hours. Infrared absorption analysis indicated complete consumption of isocyanate.

Synthesis of 11- (3-triethoxysilylpropyl carbamoyloxy) undecyl 2-methylprop-2-enoate

(C11 ethoxy)

11-Hydroxyundecyl 2-methylprop-2-enoate (24.0 g,93.6 mmol) was charged to the flask, and 3-isocyanatopropyl triethoxysilane (23.1 g,93.4 mmol) was added and the mixture was stirred at 60℃for 48 hours. Infrared absorption analysis indicated complete consumption of isocyanate.

Synthesis of 2- (3-trimethoxysilylpropyl carbamoyloxy) ethyl 2-methylprop-2-enoate

(C2 methoxy)

3-Isocyanatopropyl trimethoxysilane (34.46 g,0.1678 mol) and K-Kat XK-672 (0.055 g,1000ppm based on total solids) were charged into a flask and cooled. HEMA (20.54 g,0.1578 mol) was then added dropwise. The reaction was monitored by FTIR for the presence of an-NCO peak at 2265cm ^-1.

M-C2-U-C11-TMS

M-C2-U-C11-TMS was prepared according to U.S. Pat. No. 10,975,229 B1 (column 50; comparative Synthesis example 1).

Surface treatment of fillers

Glass filling (G)

Filler GM32087 (UF 0.4), ethanol (ratio 1:2) and 1 wt% (relative to the weight of filler) of 25% aqueous ammonia were added to the slurry, mixed in an ultrasonic bath for 3 hours, and then silane was added.

The mixture was stirred for 3 hours at RT, then the solvent was removed in a rotary evaporator (about 20 mbar) at 45 ℃, sieved with a 200 μm sieve, and then further evaporated in a rotary evaporator (about 20 mbar) at 100 ℃ for 1 hour.

Silica-zirconia cluster filler (SiO 2/ZrO 2)

The corresponding silane (10.5% relative to the weight of the filler) was dissolved in ethyl acetate (EtOAc) or 1-methoxy-2-Propanol (PGME). The solvent is used in a proportion of 100% to 200% relative to the weight of the filler. The silane was mixed into the solvent using a magnetic stirring bar.

The addition of the SiO2/ZrO2 clusters of filler to the solution slowly ensures that the magnetic stirring bar continues to stir the solution as its viscosity increases due to filler addition. Once the filler was added, 2 wt% (relative to the weight of filler) of 30% ammonia was added to the slurry. If EtOAc is used, the slurry is allowed to react overnight at room temperature. The slurry was dried by pouring the slurry into a glass marmite dish and evaporating ethyl acetate in a solvent oven set at 85 ℃ for 90 minutes. The filler was then sieved through a 70 micron sieve. If PGME is used, after the addition of ammonia, the slurry is placed on a rotary evaporator and heated to 85 ℃ for 1 hour. It is then dried in a glass tray like another.

Resin for glass filler (Re-G)

Resins of BisEMA2 (68.8 wt%), UDMA (19.7 wt%), TEGDMA (9.8 wt%), CPQ (0.16 wt%), DPIFP (0.3 wt%), EDMAB (0.6 wt%), BHT (0.09 wt%), T R796 (0.6 wt%) were used.

The resin composition was prepared by mixing and slightly heating the components under light-shielding conditions until a clear solution was formed.

Resin for silica-zirconia cluster filler (Re-SiO ₂/ZrO₂)

Resins were used, bisEMA2 (78.6%), TEGDMA (19.65%), CPQ (0.16%), DPIFP (0.3%), EDMAB (0.6%), BHT (0.09%), T R796 (0.6%).

Curable composition

The surface-treated filler is mixed/kneaded with the resin composition until a uniform composition is obtained. Mixing was performed using a Flak-Tek high speed mixer. The composition is degassed by applying a vacuum appropriately.

The content of glass filler G in the composition Re-G was 65% by weight. The cluster filler SiO2/ZrO2 content in the composition Re-SiO2/ZrO2 was 66% by weight.

The resulting composition was filled into a syringe and centrifuged. The compositions were further analyzed for viscosity (at various shear rates), flexural strength, and flexural modulus (tables 2 and 3).

TABLE 2 Re-SiO2/ZrO2 C.E. comparative examples

Table 3-Re-G; C.E.: comparative examples

Tables 2 and 3 show the viscosity profiles of different compositions of fillers surface treated with various silanes.

It can be seen that the use of the surface treated filler according to the present invention results in a desired low viscosity at low shear rates of curable compositions containing such filler. Behavior near newtonian fluids was observed.

On the other hand, as shown in the comparative example, the use of surface treated fillers with short alkylene bridging moieties results in an undesirably high viscosity at low shear rates.

Claims

1. A dental composition comprising a curable component and a surface-treated filler comprising filler particles whose surface has been treated with a surface treatment agent characterized by the following features:

comprising at least one (meth) acrylate moiety,

Comprising at least one hydrolyzable silane moiety,

Comprising only one urethane moiety,

Comprising a linear alkylene moiety AM1 linking said at least one (meth) acrylate moiety to said urethane moiety,

Comprising a linear alkylene moiety AM2 linking said at least one hydrolyzable silane moiety to said carbamate moiety, and

2. Dental composition according to the preceding claim, the surface treatment agent being characterized by the following features:

Comprising only one (meth) acrylate moiety,

Comprising at least one hydrolyzable silane moiety, preferably selected from

-Si(R²)_o(R³)_3-o

Wherein R ² = independently selected from Cl, br, O-C _1-4 alkyl, O-C _1-4 acyl, R ³ = independently selected from C _1-4 alkyl, O = 1 to 3,

Comprising only one urethane moiety,

Comprising a linear alkylene moiety AM1 linking said (meth) acrylate moiety to said one urethane moiety, said linear alkylene moiety AM1 comprising 6 to 12C atoms, and

Comprising one linear alkylene moiety AM2 linking said at least one hydrolyzable silane moiety to said urethane moiety, said linear alkylene moiety AM2 comprising 1 to 4C atoms.

3. The dental composition according to any one of the preceding claims, the surface treatment agent being characterized by the formula:

H₂C=CHR¹-CO-O-(CH₂)_n-X-CO-Y-(CH₂)_m-Si(R²)_o(R³)_3-o

4. The dental composition according to any of the preceding claims, the surface treatment agent having a molecular weight Mw in the range of 300g/mol to 800 g/mol.

5. The dental composition according to any of the preceding claims, the surface treatment agent being selected from the following molecules and mixtures thereof:

。

6. The dental composition according to any of the preceding claims, the filler comprising particles selected from the group consisting of non-aggregated and non-aggregated nano-sized particles of SiO ₂、ZrO₂ and mixtures thereof, aggregated nano-sized particles of SiO ₂、ZrO₂ and mixtures thereof, aggregated nano-sized particles of SiO ₂、ZrO₂、Al₂O₃ and mixtures thereof, non-acid reactive particles of glass, silica, metal oxides or mixtures thereof, acid reactive particles of glass, metal oxides and hydroxides and mixtures thereof,

Wherein individual ones of the nano-sized particles have an average particle size of less than 100 nm.

7. The dental composition according to any one of the preceding claims comprising 40 to 80 wt% of the surface treated filler, relative to the weight of the dental composition.

8. The dental composition according to any one of the preceding claims, comprising the following components:

a. in an amount of 40 to 80% by weight of a surface-treated filler,

B. In particular in an amount of from 5 to 50% by weight,

D. in particular in an amount of 0 to 10% by weight,

Wt% is relative to the weight of the dental composition.

9. The dental composition according to any one of the preceding claims, comprising:

a surface treated filler in an amount of 40 to 80 weight percent, the filler particles selected from the group consisting of non-aggregated, non-agglomerated nano-sized particles of SiO ₂、ZrO₂ or mixtures thereof, aggregated nano-sized particles of SiO ₂、ZrO₂ or mixtures thereof, agglomerated nano-sized particles of SiO ₂、ZrO₂、Al₂O₃ or mixtures thereof, non-acid reactive particles of glass, silica, metal oxides or mixtures thereof, acid reactive particles of glass, metal oxides and hydroxides or mixtures thereof, wherein the individual particles of the nano-sized particles have an average particle size of less than 100nm,

An initiator system in an amount of 0.1 to 5% by weight, said initiator system being suitable for curing the curable component and comprising a photoinitiator system and/or a redox initiator system,

An additive in an amount of 0 to 10 wt%,

Weight% is relative to the weight of the dental composition,

The surface treatment is characterized by the following features:

Comprising only one (meth) acrylate moiety,

Comprising at least one trimethoxysilane or triethoxysilane moiety,

Comprising only one urethane moiety,

10. The dental composition according to any one of the preceding claims, which does not comprise a rheology modifier, characterized before hardening by the following features, alone or in combination:

a. viscosity at 25℃and shear rate of 0.01s ^-1 Pa, 5Pa S to 1,500Pas,

B. can harden within 10 minutes after irradiation with light having a wavelength in the range of 400nm to 700 nm;

pH 7 or less.

11. The dental composition according to any one of the preceding claims, characterized after hardening by the following features, alone or in combination:

a. Flexural strength from 100MPa to 200MPa, determined according to ISO 4049 (2019);

b. Flexural modulus from 4GPa to 8GPa, determined according to ISO 4049 (2019).

12. A kit comprising the dental composition according to any of the preceding claims and the following parts, alone or in combination, dental adhesive, dental curing light, application instrument.

13. A dental composition for use in a method of repairing a tooth in the oral cavity of a mammal, the dental composition being as described in any one of claims 1 to 11, the method comprising the steps of:

Contacting the dental composition with the surface of the tooth to be repaired,

Curing the dental composition by applying radiation.

14. A method for producing a dental composition according to any one of claims 1 to 11, the method comprising the steps of:

optionally combining filler particles with the surface treatment agent using a dispersion,

Reacting the surface treatment agent with the filler particles,

The optional dispersion liquid is removed and the solution is mixed,

Optionally drying and sieving the surface-treated filler particles.

15. Use of a surface treated filler as described in any of claims 1 to 11 for reducing the viscosity of a dental composition according to any of claims 1 to 11 at low shear rates.