Systems and method for additive manufacturing of dental devices using photopolymer resins

Patent metadata

Field	Value
Publication number	US-2021030516-A1
Application number	US-202016942330-A
Country	US
Kind code	A1
Filing date	Jul 29, 2020
Priority date	Jul 29, 2019
Publication date	Feb 4, 2021
Grant date	—

Abstract

Strategies that reduce shrinkage and ultimately warping of parts that are directly fabricated from photopolymer resins. This increases the accuracy of directly fabricated parts, which is essential for patient specific applications. Implementing these strategies can reduce the need for directly fabricated parts to have supporting structures, which can reduce pre-processing and post-processing steps and facilitate an easier route for production level scale of additive manufacturing.

First claim

What is claimed is:

1 . A method of manufacturing an oral device, comprising:
directly fabricating a plurality of layers of resin to form a body comprising a lower substantially planar surface and an upper surface; and wherein the lower, planar surface is fabricated directly to a build platform and wherein at least a first one of the plurality of layers is cured with a first dose to a first strength and a at least a second one of the plurality of layers is cured to a second dose to a second strength to inhibit warpage of the body.

2 . The method of claim 1 , wherein the oral device further comprises at least one attachment and at least one support coupling the attachment to the body, wherein the method further comprising directly fabricating a plurality of support layers to form the support and a plurality of attachment layers to form the attachment.

3 . The method of claim 1 , further comprising directly fabricating each of the plurality of layers with a similar amount of polymer cross-linking.

4 . The method of claim 1 , further comprising directly fabricating a first layer at the planar surface and a second layer at the upper surface with a greater amount of polymer cross-linking than an amount of polymer cross-linking of an inner plurality of layers between the first layer and the second layer.

5 . The method of claim 4 , further comprising directly fabricating the first layer and the second layer with the same amount of polymer cross-linking.

6 . The method of claim 4 , further comprising directly fabricating each layer of the inner plurality of layers with the same amount of polymer cross-linking.

7 . The method of claim 1 , wherein the body has a width, length, and thickness, wherein the thickness is at least 0.25 times the length of the body.

8 . The method of claim 1 , further comprising directly fabricating the lower surface with a pattern of platforms.

9 . The method of claim 8 , wherein the pattern comprises one or more of a checkerboard pattern, a tile pattern, or a stripe pattern.

10 . The method of claim 8 , further comprising directly fabricating the platforms to have an area between twenty-five percent and seventy-five percent of an area bounded by a perimeter of the plurality platforms.

11 . The method of claim 8 , further comprising directly fabricating the platforms to have a taper that widens from a face of a platform towards the upper surface.

12 . The method of claim 8 , wherein the lower surface has a pattern comprising areas of resin having a high amount of polymer cross-linking and areas of resin having a lower amount of polymer cross-linking.

13 . The method of claim 12 , wherein the pattern comprises one or more of a checkerboard pattern, a tile pattern, or a stripe pattern.

14 . A method of fabricating a device, the method comprising:
slicing a 3D model of the device into a plurality of layers; determining a first mask of a first area for a first of a plurality of layers; determine a second mask of a second area for the first of the plurality of layers; and outputting instructions for forming a plurality of layers.

15 . The method of claim 14 , wherein determining the first mask includes determining a first curing dose.

16 . The method of claim 15 , wherein determining a second mask includes determining a second curing dose, less than the first curing dose.

17 . The method of claim 16 , wherein the first curing dose is sufficient to cure resin of the first areas to its green strength.

18 . The method of claim 16 , wherein the second curing dose is insufficient to cure resin of the second areas to its green strength.

19 . The method of claim 18 , wherein the first area includes perimeters of the first of the plurality of layers and the second area includes the first area and the perimeters, and wherein the first dose is insufficient to cure resin of the first areas to its green strength and the second dose second dose is sufficient cures the resin of the first areas to the green strength but is insufficient to cure the second areas to the green strength.

20 . The method of claim 14 , further comprising:
determining first and second masks for each of the remaining plurality of layers.

Assignees

• Align Technology Inc

Inventors

• O'Leary Siobhan
• Webber Peter
• Cole Michael Christopher

Classifications

• B29C64/124 Primary

  using layers of liquid which are selectively solidified · CPC title

• A61C13/0019 Primary

  using three dimensional printing · CPC title

• A61C7/002 Primary

  Orthodontic computer assisted systems · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title