3D-printed orthodontic splint made of crosslinked polymers

Patent metadata

Field	Value
Publication number	US-12070368-B2
Application number	US-201917274208-A
Country	US
Kind code	B2
Filing date	Sep 18, 2019
Priority date	Sep 20, 2018
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

The present invention relates to an orthodontic splint made of a crosslinked polymer, wherein the crosslinked polymer has a glass transition temperature T g , determined by means of dynamic-mechanical analysis at a frequency of 1/s DMA as peak tan δ, of ≥25° C. and ≤60° C., a modulus of elasticity, determined by means of dynamic-mechanical analysis as the storage modulus E′ at a frequency of 1/s at 35° C., of ≥500 MPa and ≤4000 MPa, and a loss factor tan δ, determined by means of dynamic-mechanical analysis at a frequency of 1/s at 35° C., of ≥0.08. The invention further relates to a process for producing such splints.

First claim

The invention claimed is:

1. A method for producing an orthodontic aligner, comprising:
i) selecting a crosslinkable resin; and
ii) shaping the aligner by crosslinking the crosslinkable resin to form a crosslinked polymer,
wherein selecting the crosslinkable resin includes a criterion that a crosslinked polymer obtained after crosslinking of the crosslinkable resin has a glass transition temperature Tg, determined by dynamic mechanical analysis at a frequency of 1/s DMA as peak tan δ, of 25° C. and ≤60° C., an elasticity modulus, determined by dynamic mechanical analysis as storage modulus E′ at a frequency of 1/s at 35° C., of ≥500 MPa and ≤4000 MPa, and a loss factor tan δ, determined by dynamic mechanical analysis at a frequency of 1/s at 35° C., of ≥0.08,
wherein the crosslinkable resin comprises a first monomer and a second monomer, said first monomer being a (meth)acrylic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≤0° C., and said second monomer being a (meth)acrylic or styrenic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≥60° C., and where the first monomer is present in a fraction of ≥5 to ≤40 weight %, based on a total weight of the resin, and the second monomer is present in a fraction of ≥20 to ≤80 weight %, based on the total weight of the resin.

2. The method as claimed in claim 1 , wherein the aligner is shaped by crosslinking the crosslinkable resin in a casting mold corresponding to the aligner.

3. The method as claimed in claim 1 , wherein the aligner is shaped via an additive manufacturing method.

4. The method as claimed in claim 1 , wherein the crosslinkable resin has free isocyanate groups, measured by 13C NMR, in a concentration ≥1 wt %, based on a total weight of the crosslinkable resin.

5. The method as claimed in claim 1 , wherein the crosslinkable resin has free alcohol groups, measured by 13C NMR, in a concentration ≥0.5 wt %, based on a total weight of the crosslinkable resin.

6. An orthodontic aligner, comprising
a crosslinked polymer having a glass transition temperature Tg, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≥25° C. and ≤60° C., an elasticity modulus, determined by dynamic mechanical analysis as storage modulus E′ at a frequency of 1/s at 35° C., of ≥500 MPa and ≤4000 MPa, and a loss factor tan δ, determined by dynamic mechanical analysis at a frequency of 1/s at 35° C., of 0.08,
wherein the crosslinked polymer is a copolymer which comprises units based on a first monomer and a second monomer, said first monomer being a (meth)acrylic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≤0° C., and said second monomer being a (meth)acrylic or styrenic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≥60° C., and where units based on the first monomer are present in a fraction of ≥5 to ≤40 weight %, based on a total weight of the crosslinked polymer, and units based on the second monomer are present in a fraction of ≥20 to ≤80 weight %, based on the total weight of the crosslinked polymer, wherein the crosslinked polymer is obtained from a resin comprising:
15-20 weight % of a urethane (meth)acrylate containing isocyanurate groups,
1-5 weight % of alkanediol di(meth)acrylate,
20-30 weight % of monofunctional (meth)acrylate whose resultant homopolymer has a glass transition temperature of ≤0° C.;
50-60 weight % of monofunctional (meth)acrylate whose resultant homopolymer has a glass transition temperature of ≥60° C., each on the basis of the total weight of the resin.

7. The orthodontic aligner as claimed in claim 6 , wherein the crosslinked polymer has an isocyanurate fraction, ascertained via 13C NMR, of ≥3%.

8. The orthodontic aligner as claimed in claim 6 , wherein the crosslinked polymer has a refractive index, measured with an Abbe refractometer, of ≥1.48 RI and ≤1.58 RI.

9. The orthodontic aligner as claimed in claim 6 , wherein the crosslinked polymer has a mean network arc length according to Flory and Huggins of ≥300 g/mol and ≤5000 g/mol.

10. The orthodontic aligner as claimed in claim 6 , wherein the crosslinked polymer is a transparent polymer having a light transmittance, measured in a UV-VIS spectrometer on a sample with a thickness of 1 mm in a wavelength range of 400-800 nm, of ≥50%.

11. The orthodontic aligner as claimed in claim 6 , wherein the crosslinked polymer is a transparent polymer comprising polyurethanes and/or polysilicones and has an Abbe number of ≥20.

12. An orthodontic aligner, comprising
a crosslinked polymer having a glass transition temperature Tg, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≥25° C. and ≤60° C., an elasticity modulus, determined by dynamic mechanical analysis as storage modulus E′ at a frequency of 1/s at 35° C., of ≥500 MPa and ≤4000 MPa, and a loss factor tan δ, determined by dynamic mechanical analysis at a frequency of 1/s at 35° C., of 0.08,
wherein the crosslinked polymer is a copolymer which comprises units based on a first monomer and a second monomer, said first monomer being a (meth)acrylic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≤0° C., and said second monomer being a (meth)acrylic or styrenic monomer whose homopolymer has a glass transition temperature, determined by dynamic mechanical analysis at a frequency of 1/s as peak tan δ, of ≥60° C., and where units based on the first monomer are present in a fraction of ≥5 to ≤40 weight %, based on a total weight of the crosslinked polymer, and units based on the second monomer are present in a fraction of ≥20 to ≤80 weight %, based on the total weight of the crosslinked polymer, wherein the crosslinked polymer is obtained from a resin comprising:
10-15 weight % of a urethane (meth)acrylate containing isocyanurate groups,
5-10 weight % of monofunctional methacrylate of a terpene alcohol,
20-35 weight % of monofunctional (meth)acrylate whose resultant homopolymer has a glass transition temperature of ≤0° C.;
55-60 weight % of monofunctional (meth)acrylate whose resultant homopolymer has a glass transition temperature of ≥60° C., each on the basis of the total weight of the resin.

13. The orthodontic aligner as claimed in claim 12 , wherein the crosslinked polymer has an isocyanurate fraction, ascertained via 13C NMR, of ≥3%.

14. The orthodontic aligner as claimed in claim 12 , wherein the crosslinked polymer has a refractive index, measured with an Abbe refractometer, of ≥1.48 RI and ≤1.58 RI.

15. The orthodontic aligner as claimed in claim 12 , wherein the crosslinked polymer has a mean network arc length according to Flory and Huggins of ≥300 g/mol and ≤5000 g/mol.

16. The orthodontic aligner as claimed in claim 12 , wherein the crosslinked polymer is a transparent polymer having a light transmittance, measured in a UV-VIS spectrometer on a sample with a thickness of 1 mm in a wavelength range of 400-800 nm, of ≥50%.

17. The orthodontic aligner as claimed in claim 12 , wherein the crosslinked polymer is a transparent polymer comprising polyurethanes and/or polysilicones and has an Abbe number of ≥20.

Assignees

• Stratasys Inc

Inventors

• Achten Dirk
• Wagner Roland
• Tomczyk Christoph
• Buesgen Thomas

Classifications

• A61C2201/00

  Material properties · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29L2031/753

  Medical equipment; Accessories therefor (bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008) · CPC title