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EP-4739252-A1 - ADDITIVE MANUFACTURING OF DENTAL PROSTHESES

EP4739252A1EP 4739252 A1EP4739252 A1EP 4739252A1EP-4739252-A1

Abstract

Modeling material formulations usable in additive manufacturing of a denture structure, and additive manufacturing of denture structures employing same are provided. The modeling material formulations and the additive manufacturing parameters provide denture structures that exhibit mechanical, physical and biocompatibility properties that meet the requirements of the acceptable standards.

Inventors

  • NAHARI, Gilad
  • HIRSCHSOHN, YANIV
  • PERI, Dani
  • KHAIMOV, Lior
  • VINTS, Inna
  • SHPAYZER, Elena
  • ZONDER, Lior

Assignees

  • Stratasys Ltd.

Dates

Publication Date
20260513
Application Date
20240705

Claims (20)

  1. 1. A modeling material formulation usable in additive manufacturing of a denture structure, the modeling material formulation comprising: at least one multi-functional ethoxylated aromatic (meth) acrylate featuring at least 10 ethoxylated groups and/or Tg lower than 0 °C (Component D2), in a total amount of from 15 to 25 % by weight, of the total weight of the formulation; at least one multi-functional urethane (meth)acrylate featuring Tg lower than 100 °C (Component G), in a total amount of from 15 to 25 % by weight, of the total weight of the formulation; at least one mono-functional alicyclic (meth) acrylate (Component E2), in a total amount of at least 40, or at least 45, or of from 45 to 55, % by weight, of the total weight of the formulation; at least one mono-functional acrylate (Component E3), in a total amount of from 3 to 10, or from 5 to 10, or from 3 to 8, % by weight, of the total weight of the formulation; and at least one dispersant (Component H).
  2. 2. The formulation of claim 1, wherein said Component D2 comprises a multifunctional ethoxylated aromatic (meth)acrylate featuring at least 10 ethoxylated groups and featuring, when hardened, Tg lower than 0 °C.
  3. 3. The formulation of claim 1 or 2, wherein said Component D2 has a molecular weight of at least 1,000 grams/mol.
  4. 4. The formulation of any one of claims 1 to 3, wherein said Component D2 is a multifunctional ethoxylated aromatic methacrylate featuring at least 10 ethoxylated groups.
  5. 5. The formulation of any one of claims 1 to 4, wherein said Component G comprises a multi-functional urethane (meth) acrylate having a molecular weight of at least 1,000 grams/mol.
  6. 6. The formulation of any one of claims 1 to 5, wherein said Component G features Tg that ranges from 0 to 100, or from 50 to 100, °C (Component G2).
  7. 7. The formulation of any one of claims 1 to 6, wherein said Component G comprises a multi-functional urethane methacrylate.
  8. 8. The formulation of any one of claims 1 to 7, wherein said Component D2 comprises a multi-functional ethoxylated aromatic methacrylate featuring at least 10 ethoxylated groups, features, when hardened, Tg lower than 0 °C, and has a molecular weight of at least 1,000 grams/mol.
  9. 9. The formulation of any one of claims 1 to 8, wherein said Component G comprises a Component G2 which is a multi-functional a multi-functional urethane methacrylate featuring, when hardened, Tg that ranges from 0 to 100, or from 50 to 100, °C, and having a molecular weight of at least 1,000 grams/mol.
  10. 10. The formulation of any one of claims 1 to 9, wherein a total amount of said at least one Component D2 and said at least one Component G or said Component G2 ranges from about 30 to about 50, % by weight of the total weight of the formulation.
  11. 11. The formulation of any one of claims 1 to 10, wherein said at least one Component E2 has a molecular weight (MW) of no more than 500, or of from 100 to 500 grams/mol.
  12. 12. The formulation of any one of claims 1 to 11, wherein each of said at least one Component E2 independently features, when hardened, Tg lower than 100 °C, or lower than 50 °C, or of from 20 to 60 °C, or of from 20 to 50 °C.
  13. 13. The formulation of any one of claims 1 to 12, wherein said at least one Component E2 comprises a mono-functional alicyclic acrylate having a molecular weight (MW) of no more than 500, or of from 100 to 500, grams/mol and featuring, when hardened, Tg lower than 100 °C, or lower than 50 °C or of from 20 to 60 °C, or of from 20 to 50 °C.
  14. 14. The formulation of any one of claims 1 to 13, wherein said at least one Component E3 comprises a mono-functional hydrophilic or amphiphilic acrylate having a molecular weight (MW) of no more than 500, or of from 100 to 500, grams/mol.
  15. 15. The formulation of any one of claims 1 to 14, wherein said at least one Component E3 comprises a mono-functional hydrophilic or amphiphilic acrylate featuring, when hardened, Tg higher than 50 °C, or higher than 80 °C, or of from 50 to 150 °C.
  16. 16. The formulation of any one of claims 1 to 15, wherein an amount of said dispersant (Component H) is at least 0.1, or from 0.1 to 1, or from 0.1 to 0.5, % by weight of the total weight of the formulation.
  17. 17. The formulation of claim 16, wherein said dispersant has curable groups.
  18. 18. The formulation of claim 17, wherein said dispersant is a multi-functional aliphatic silicon (meth)acrylate.
  19. 19. The formulation of claim 1, wherein: said Component D2 comprises a multi-functional ethoxylated aromatic methacrylate featuring at least 10 ethoxylated groups and having a molecular weight of at least 1,000 grams/mol, which features, when hardened, Tg lower than 0 °C, and; said Component G comprises a Component G2 which is a multi-functional a multifunctional urethane methacrylate having a molecular weight of at least 1,000 grams/mol and featuring, when hardened, Tg that ranges from 0 to 100, or from 50 to 100, °C; a total amount of said at least one Component D2 and said at least one Component G2 ranges from 30 to 50, % by weight of the total weight of the formulation; said at least one Component E2 comprises a mono-functional alicyclic acrylate having a molecular weight (MW) of no more than 500, or of from 100 to 500, grams/mol and featuring, when hardened, Tg lower than 100 °C, or lower than 50 °C, or (of from 20 to 60 °C, or of from 20 to 50 °C; said at least one Component E3 comprises a mono-functional hydrophilic or amphiphilic acrylate having a molecular weight (MW) of no more than 500, or of from 100 to 500, grams/mol and featuring, when hardened, Tg higher than 50 °C, or higher than 80 °C, or of from 50 to 150 °C; and an amount of said Component H is at least 0.1 or ranges from 0.1 to 1 or from 0.1 to 0.5, % by weight of the total weight of the formulation.
  20. 20. The formulation of any one of claims 1 to 19, further comprising a photoinitiator (Component J).

Description

ADDITIVE MANUFACTURING OF DENT AU PROSTHESES RELATED APPLICATION This application claims the benefit of priority under 35 USC § 119(e) of U.S. Provisional Patent Application No. 63/525,074 filed on 5 July 2023, the contents of which are incorporated herein by reference in their entirety. This application is related to co-filed PCT International Patent Application entitled “METHOD AND SYSTEM FOR CORRECTING COLOR ARTIFACTS IN ADDITIVE MANUFACTURING” (Attorney Docket No. 100036), which claims priority from U.S. Provisional Patent Application No. 63/525,066, the contents of both are all incorporated herein by reference in their entirety. FIELD AND BACKGROUND OF THE INVENTION The present invention, in some embodiments thereof, relates to additive manufacturing and, more particularly, but not exclusively, to curable formulations which are usable in additive manufacturing of dental prostheses, including denture teeth, denture base and monolithic denture structures. Additive manufacturing (AM) is a technology enabling fabrication of arbitrarily shaped structures directly from computer data via additive formation steps. The basic operation of any AM system consists of slicing a three-dimensional computer model into thin cross sections, translating the result into two-dimensional position data and feeding the data to control equipment which fabricates a three-dimensional structure in a layer-wise manner. Additive manufacturing entails many different approaches to the method of fabrication, including three-dimensional (3D) printing such as 3D inkjet printing, electron beam melting, stereolithography, selective laser sintering, laminated object manufacturing, fused deposition modeling and others. Some 3D printing processes, for example, 3D inkjet printing, are being performed by a layer by layer inkjet deposition of building materials. Thus, a building material is dispensed from a dispensing head having a set of nozzles to deposit layers on a supporting structure. Depending on the building material, the layers may then be cured or solidified. Curing may be by exposure to a suitable condition, and optionally by using a suitable device. The building material includes an uncured model material (also referred to as “uncured modeling material” or “modeling material formulation”), which is selectively dispensed to produce the desired object, and may also include an uncured support material (also referred to as "uncured supporting material” or “support material formulation”) which provides temporary support to specific regions of the object during building and assures adequate vertical placement of subsequent object layers. The supporting structure is configured to be removed after the object is completed. In some known inkjet printing systems, the uncured model material is a photopolymerizable or photocurable material that is cured, hardened or solidified upon exposure to ultraviolet (UV) light after it is jetted. The uncured model material may be a photopolymerizable material formulation that has a composition which, after curing, gives a solid material with mechanical properties that permit the building and handling of the three-dimensional object being built. The modeling material formulation typically include a reactive (curable) component and a photoinitiator. The photo-initiator may enable at least partial solidification (hardening) of the uncured support material by curing with the same UV light applied to form the model material. The solidified material may be rigid, or may have elastic properties. The support material is formulated to permit fast and easy cleaning of the object from its support. The support material may be a polymer, which is water-soluble and/or capable of swelling and/or breaking down upon exposure to a liquid solution, e.g. water, alkaline or acidic water solution. The support material formulation may also include a reactive (curable) component and a photo-initiator. In order to be compatible with most of the commercially- available print heads utilized in a 3D inkjet printing system, the uncured building materials should feature the following characteristics: a relatively low viscosity (e.g., Brookfield Viscosity of up to 50 centipoises or cps, or up to 35 cps, preferably from 8 to 25 cps) at the working (e.g., jetting) temperature; Surface tension of from about 25 to about 55 Dyne/cm, preferably from about 25 to about 40 Dyne/cm; and a Newtonian liquid behavior and high reactivity to a selected curing condition, to enable fast solidification of the jetted layer upon exposure to a curing condition, of no more than 1 minute, preferably no more than 20 seconds. The hardened modeling material which forms the final object typically exhibits a heat deflection temperature (HDT) which is higher than room temperature, in order to assure its usability. Desirably, the hardened modeling material exhibits an HDT of at least 35 °C. For an object to be stable at variable conditions, a higher HDT is known to