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EP-3850022-B1 - COMPOSITE MATERIALS INCLUDING CERAMIC FIBERS AND NANOCLUSTERS, DENTAL PRODUCTS, KITS, AND METHODS OF MAKING AND USING SAME

EP3850022B1EP 3850022 B1EP3850022 B1EP 3850022B1EP-3850022-B1

Inventors

  • Wilson, David M.
  • CRAIG, BRADLEY D.
  • AGRE, Mark B.
  • MCGEE, Kari A.
  • HELLER, DAIMON K
  • CHIU, William V.
  • HUGHES, GARETH A.

Dates

Publication Date
20260513
Application Date
20190906

Claims (11)

  1. A composite material, comprising: 20 to 40 weight percent (wt.%) of a polymerizable component; 6 to 40 wt.% of ceramic fibers, wherein the ceramic fibers comprise alumina fibers, alumina-silica fibers, aluminum borosilicate fibers, zirconia-silica fibers, borosilicate glass fibers, silicate fibers modified with alkalis or alkaline earths, fused silica fibers, leached silica fibers, quartz fibers, fiberglass, or combinations thereof; and 30 to 70 wt.% of silica-zirconia nanoclusters, a nanocluster being a group of two or more nanoparticles associated by relatively weak, but sufficient intermolecular forces that cause the nanoparticles to clump to together, even when dispersed in a hardenable resin, where a nanoparticle is a discrete non-fumed metal oxide particle having a maximum particle size in the range of 5 nm to 200 nm, said maximum particle size being the largest dimension of the particle, wherein the wt.% values of the composite material are based on a total weight of the composite material and total to a value of 100 wt.%, wherein each of the ceramic fibers has a diameter and a length, wherein the ceramic fibers have an arithmetic mean diameter of 0.3 micrometers to 2 micrometers, and wherein the length of fifty percent of the ceramic fibers, based on a total number of the ceramic fibers, is at least 25 micrometers and the length of ninety percent of the ceramic fibers, based on the total number of the ceramic fibers, is no greater than 200 micrometers.
  2. The composite material of claim 1, wherein the ceramic fibers comprise alumina-silica fibers, borosilicate glass fibers, or combinations thereof.
  3. The composite material of any of claim 1 or claim 2, wherein the composite material comprises up to 15 wt.% of nanoparticles.
  4. The composite material of any of claims 1-3, wherein the polymerizable component forms a hardened polymerizable component having a refractive index, and wherein the ceramic fibers have a refractive index value within 0.1 or less of the refractive index of the hardened polymerizable component, preferably wherein the ceramic fibers have a refractive index value of 1.40 to 1.65.
  5. The composite material of any of claims 1-4, wherein the composite material forms a hardened composite material having each of a diametral tensile strength (DTS) of 65 megapascals (MPa) or greater, a flexural strength of 170 MPa or greater, and a fracture toughness of 2.50 megapascals·square root meters (MPa·m 1/2 ) or greater; the diametral tensile strength (DTS), flexural strength, and fracture toughness being determined according to the description.
  6. The composite material of any of claims 1-5, wherein the composite material forms a hardened composite material having a polish retention of 40 gloss units or greater at 60° after 6000 brush cycles; the polish retention being determined according to the description.
  7. A dental product for use as a dental restorative, a dental adhesive, a dental mill blank, a dental cement, a dental prosthesis, an orthodontic device, an orthodontic adhesive, a dental casting material, an artificial crown, an anterior filling, a posterior filling, a cavity liner, or a dental coating, the dental product made by a method comprising hardening the composite material of any of the preceding claims 1-6.
  8. The dental product of claim 7, wherein prior to said hardening, the method of making the dental product comprises: placing the composite material near or on a tooth surface; changing the shape of the composite material near or on the tooth surface; and wherein after hardening the composite material, the method optionally comprises polishing the composite material .
  9. A method of making a composite material, comprising: obtaining a plurality of components comprising: 20 to 40 wt.% of a polymerizable component; 6 to 40 wt.% of ceramic fibers, wherein the ceramic fibers comprise alumina fibers, alumina-silica fibers, aluminum borosilicate fibers, zirconia-silica fibers, borosilicate glass fibers, silicate fibers modified with alkalis or alkaline earths, fused silica fibers, leached silica fibers, quartz fibers, fiberglass, or combinations thereof; and 30 to 70 wt.% of silica-zirconia nanoclusters, a nanocluster being a group of two or more nanoparticles associated by relatively weak, but sufficient intermolecular forces that cause the nanoparticles to clump to together, even when dispersed in a hardenable resin, where a nanoparticle is a discrete non-fumed metal oxide particle having a maximum particle size in the range of 5 nm to 200 nm, said maximum particle size being the largest dimension of the particle; wherein the wt.% values of the composite material are based on a total weight of the composite material and total to a value of 100 wt.%, wherein each of the ceramic fibers has a diameter and a length, wherein the ceramic fibers have an arithmetic mean diameter of 0.3 micrometers to 2 micrometers, and wherein the length of fifty percent of the ceramic fibers, based on a total number of the ceramic fibers, is at least 25 micrometers and the length of ninety percent of the ceramic fibers, based on the total number of the ceramic fibers, is no greater than 200 micrometers; and admixing the plurality of components to make the composite material.
  10. A kit comprising: a composite material of any one of claims 1-6; and at least one container to hold the composite material.
  11. The kit of claim 10, further including at least one dental component selected from the group of a cement, an adhesive, an abrasive, a polishing paste, an instrument, software, a mill, a CAD/CAM system, a composite, a porcelain, a stain, a bur, an impression material, a dental mill blank, or a combination thereof.

Description

TECHNICAL FIELD The present disclosure broadly relates to composite materials, and more particularly composite materials containing ceramic fibers. BACKGROUND Direct dental restorative materials consist of a curable phase, typically a methacrylate resin, an initiator and a filler system. These materials are typically highly filled with particulate such as nanoscale particles, micrometer milled materials and/or solution grown inorganics. Furthermore, similar compositions made from pre-cured "composites" (e.g., dental mill blanks) have been introduced to the market, where the material is cured out of the mouth and shaped into a final restorative shape (e.g., inlay, onlay or crown) via a reduction process (e.g., milling). All of these dental restorative materials have requirements that include high strength, stiffness, and fracture toughness to function in the oral environment. Especially in large posterior restorations, a higher fracture toughness material is highly desirable. Attempts have been made to include fibers in dental restorative materials in order to improve their mechanical properties. However, this has come at a cost to handling and aesthetic characteristics. The use of fibers unfortunately creates a stiff, "crunchy" type of handling that is difficult to work with (e.g., shape, and feather). Once cured, the surfaces of these dental restorative materials rapidly lose their gloss with every day wear. Additionally, many of these dental restorative materials produce a highly opaque material due to refractive index mismatch between the fiber and the resin. This refractive index mismatch results in a less than desirable aesthetic result. For example composite materials comprising ceramic fibers and nanoclusters are known from US 2018/028413 A1. As such, there is a need in the art for a composite material that includes fibers, where the composite material is easy to handle and provides good aesthetics properties while still providing the necessary mechanical properties for use as a dental restorative material. SUMMARY The present disclosure provides a composite material having improved handling properties along with good aesthetic qualities while still providing the necessary mechanical properties for use as a dental restorative material. More specifically, in a first aspect, a composite material is provided as defined in the claims. In a second aspect, a dental product is provided for use as a dental restorative as defined in the claims. The dental product is made by hardening the composite material according to the first aspect. In a third aspect, a method of making a composite material is provided as defined in the claims. In a fifth aspect, a kit is provided. The kit includes a composite material according to the first aspect; and at least one container to hold the composite material. Composite materials according to at least certain embodiments of the present disclosure can provide hardened composite materials (e.g., dental products) exhibiting good strength, good polish retention, wear rate, and/or visual appearance. The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. Brief Description of the Drawings FIG. 1 is a scanning electron microscopy (SEM) micrograph of a diametral tensile strength (DTS) fracture surface of a hardened composite material according to the present disclosure.FIG. 2 is an SEM micrograph of a DTS fracture surface of a comparative hardened composite material.FIG. 3 is an SEM micrograph of a DTS fracture surface of another hardened composite material according to the present disclosure. While the above-identified figures set forth several embodiments of the disclosure other embodiments are also contemplated, as noted in the description. The figures are not necessarily drawn to scale. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, and the invention is defined by the claims. Detailed Description of Illustrative Embodiments The present disclosure provides a composite material having improved handling properties along with good aesthetic qualities while still providing the necessary mechanical properties for use as a dental restorative material. Specifically, the composite material includes a polymerizable component, ceramic fibers and nanoclusters. The ceramic fibers used in the composite material, as discussed herein, have a small diameter. The small diameter of the ceram