Sheet based triply periodic minimal surface implants for promoting osseointegration and methods for producing same
Provided herein are implants and methods for producing implants. In at least one embodiment, the implants include sheet-based, triply periodic, minimal surface (TPMS) portions. According to one embodiment, the TPMS portions include a gyroid architecture that provides for improved osseointegration and mechanical performance over previous implants due to novel ratios of porosity to compressive strength, among other features. In one or more embodiments, the gyroid architecture is organized into unit cells that demonstrate anisotropic mechanical performance along an insertion direction. In various embodiments, the present methods include novel selective laser melting (SLM) techniques for forming the TPMS portions of implants in a manner that reduces defect formation, thereby improving compressive performance and other implant properties.
1. A 3D-printed implant comprising:
a top surface and a bottom surface;
a titanium frame comprising:
an interior portion, wherein the interior portion defines a void area; and
a titanium sheet-based triply periodic minimal surface (TPMS) portion integrally formed with the titanium frame via SLM 3D printing extending from the top surface through the void area of the titanium frame to the bottom surface, the TPMS portion comprising:
a wall density greater than 99%;
a stiffness modulus of about 3-14 GPa;
a porosity of about 55-85%; and
an ultimate compression strength of about 50-230 MPa.
2. The 3D-printed implant of claim 1 , wherein the TPMS portion is free of nodes.
3. The 3D-printed implant of claim 1 , further comprising one or more teeth extending from the top surface or bottom surface.
4. The 3D-printed implant of claim 3 , wherein the one or more teeth extend from the top or bottom surface along a surface of the titanium frame.
5. The 3D-printed implant of claim 1 , wherein the interior portion defines a second void area free of TPMS structures.
6. The 3D-printed implant of claim 1 , wherein:
the TPMS portion comprises a wall thickness of about 0.25 mm;
the stiffness modulus is about 3 GPa;
the porosity is about 85%; and
the ultimate compression strength is about 50 MPa.
7. The 3D-printed implant of claim 1 , wherein:
the TPMS portion comprises a wall thickness of about 1.00 mm;
the stiffness modulus is about 14 GPa;
the porosity is about 55%; and
the ultimate compression strength is about 227 MPa.
8. The 3D-printed implant of claim 1 , wherein the 3D-printed implant is anisotropic in an insertion direction.
9. The 3D-printed implant of claim 1 , wherein the 3D-printed implant is a spinal cage.
10. The 3D-printed implant of claim 1 , wherein the 3D-printed implant is an osteotomy wedge.
11. The 3D-printed implant of claim 1 , wherein the TPMS portion comprises a gyroid architecture.
12. A 3D-printed implant comprising:
a top surface and a bottom surface;
at least one titanium sheet based triply periodic minimal surface (TPMS) portion extending from the top surface to the bottom surface and comprising:
a wall density greater than 99%;
a stiffness modulus of about 3-14 GPa;
a porosity of about 55-85%; and
an ultimate compression strength of about 50-230 MPa.
13. The 3D-printed implant of claim 12 , wherein:
the top surface and the bottom surface define an interior portion; and
the interior portion defines at least one void area.
14. The 3D-printed implant of claim 13 , wherein the at least one titanium TPMS portion comprises a gyroid architecture.
15. The 3D-printed implant of claim 14 , wherein the at least one titanium TPMS portion is free of nodes.
16. The 3D-printed implant of claim 15 , further comprising one or more teeth extending from the top surface or the bottom surface.
17. The 3D-printed implant of claim 16 , wherein the 3D-printed implant is anisotropic in an insertion direction.
18. The 3D-printed implant of claim 12 , wherein the 3D-printed implant is a spinal cage.
19. The 3D-printed implant of claim 12 , wherein the 3D-printed implant is an osteotomy wedge.