Dudley’s tale was one of woe. He never smiled because he was self-conscious of his crooked front teeth. And as a college student, he didn’t have the cash to afford professional treatment, which can cost thousands of dollars. Armed with access to his college’s 3D printing and fabrication setup, Dudley researched orthodontics, and figured out how the plastic Invisalign trays work anatomically to shift your teeth. He also delved deeply into the manufacturing process, learning how the plastic appliance is formed and shaped to fit your teeth.
With the knowledge of an armchair orthodontist, Dudley was ready to begin making his homemade Invisalign tray. He obtained some inert retainer plastic from eBay and spent some time working with the equipment in his school’s digital fabrication lab. He discovered through trial and error that the lab’s Stratasys Dimension 1200es was accurate enough to print the tray. And when he coupled that with a vacuum forming machine and a NextEngine laser scanner, he had all the tools needed to make the tray.
He made casts of his teeth using alginate for the mold and Permastone for the cast. He placed the mold upside down in a yogurt container and filled it with liquid Permastone. He then used the laser scanner to convert the Permastone mold into a digital format that could be used for the design of the invisible plastic tray. Using the animation feature of his 3D software, Dudley created a series of frames that show his tooth moving from the crooked to the straight position. Each frame was exported as a new STL model.
Each STL model served as a template for a different aligner tray that would be worn successively to move the tooth slowly into its correct position. Dudley 3D printed each aligner template, carefully numbering them to keep them in order since the differences between them were so slight. Once the aligner templates were printed, they were shuttled off to the vacuum machine, where the retainer material was applied to the 3D-printed aligner templates. After a press of a few buttons and a quick dremeling to smooth out the edges, Dudley had a complete set of homemade Invisalign’s that he could use to straighten his crooked teeth.
And straighten they did. After 16 weeks spent wearing them almost 24/7, Dudley’s teeth are fantastic, and his smile is back. Dudley also noted that the aligners have a few added bonuses — they work well as a tray for whitening and can function as a guard to help minimize tooth wear from nighttime grinding. Dudley’s creation is thus an all-in-one appliance that works as a straightener, a whitener and a nighttime guard. All this for $60 in materials — can’t beat that.