Objet30 prime

A 7 × 7 array of cuboid-shaped microstructures with w_d and h_d of 100, 200, 300, 400, 500, 1500 and 3000 μm were designed over a flat base using AutoCAD^® 2016 (Autodesk, CA, USA). The length of the cuboids was 1 cm and a gap of 0.5 cm was provided between each of the structures. The designed structures were 3D printed in Objet30 Prime™ (Stratasys, MN, USA) with Veroclear and support SUP705 as a model material and a support material, respectively. The structures were printed in three different layer thicknesses of 16, 28, and 36 μm, each of which is termed as high quality (HQ), high speed (HS), and Draft modes of Objet30 Prime printer, respectively.

A samples test was produced in VeroClear RGD810™ thermosetting (Stratasys Inc., Minneapolis, MN, USA) polymer (rigid phase) and the base supports in SUP706B in a Objet30 Prime (Stratasys Inc., Minneapolis, MN, USA), with a resolution of 32 μm per layer in a single batch. Process parameters were kept constant during the build process. The materials were supplied by the company Stratasys™. Production was carried out under the following conditions: (i) automatic positioning; (ii) “gloss mode” option (i.e., glossy, without supporting material to wrap the piece); (iii) the resins were stored in a controlled environment, to be placed previously in the equipment, according to the supplier’s rules; (iv) supports were removed in a chemical bath of 2% Sodium Hydroxide (NaOH) and 1% Sodium Metasilicate (Na₂SIO₃); (v) mechanical tests were performed on samples as produced (no further oven curing).

STAR devices were manufactured and placed in a custom-made 3D printed holder (Objet30 Prime, Stratasys). Devices were pneumatically inflated from 1 to 9 psi using the electropneumatic actuation and control system described above. Images of membrane deflection were captured using a digital camera (Nikon DLSR) and tripod positioned in the side view. Deflection magnitude was subsequently analysed using ImageJ. Based on this strategy, a bi-chambered configuration was selected to investigate the effect of two distinct deflection magnitudes (0.58 and 1.3 mm) in our pre-clinical mouse model. It should be noted that the lower deflection magnitude was closely matched to our previous work.

An Objet30 Prime (Stratasys, Ltd., Eden Prairie, MN, USA) 3D printer was used to produce the 10 mandibular models with MJ technology. The chosen materials were a white photopolymer resin VeroWhite (Stratasys, Ltd., Eden Prairie, MN, USA) and a water-soluble support material SUP706 (Stratasys, Ltd., Eden Prairie, MN, USA). The software Objet Studio Software v. 9.2.11.6825 (Stratasys, Ltd., Eden Prairie, MN, USA) was adjusted to the following printing settings with a tray material high-speed (HS), glossy surface option and a layer thickness of 28 microns. The model was positioned in the upper left corner of the built platform. The printing time was 12 h and 14 min. Subsequently, post-processing was required to remove the water-soluble supporting structures with a WaterJet Station (Stratasys, Ltd., Eden Prairie, MN, USA).

In MJ 3D printer (Objet30Prime, Stratasys Ltd., Minneapolis, MN, USA, the drill guides were fabricated with two proprietary photopolymer resins, one as a core biocompatible material (MED610, Stratasys Ltd., Minneapolis, MN, USA), and the other as a water-soluble support material (SUP705, Stratasys Ltd., Minneapolis, MN, USA). The STL files of the drill guides were imported into the 3D printer’s slicing software (Objet Studio Software, v. 9.2.11.6825, Stratasys Ltd., Minneapolis, MN, USA). The drill guides were printed using the automatic placement functionality integrated into the software considering minimal printing time and material consumption. As this technology utilizes water-soluble support structures, the software automatically configures the drill guides angulation for optimal printing results. The drill guides were printed at a layer thickness of 28 microns with a “glossy” surface finish and in a high-speed mode. Post-processing steps were required to remove the water-soluble support structures and were performed in a WaterJet Station (Stratasys Ltd., Minneapolis, MN, USA).