Since Invisalign was first commercialized in 1999, orthodontic treatment with clear aligners has been positioned as an alternative to treatment with brackets and wires. It has continued to challenge various and even so-called difficult cases, reporting successful results. And the number of clear aligner therapy suppliers has been increasing more and more. Invisalign-like clear aligners are made by 3D printing interim models and vacuum-forming or thermoforming transparent sheets. Although they have advantages compared to conventional orthodontic treatments, they also have some disadvantages, such as making interim models, which can precipitate environmental issues and waste time and cost, and requiring many attachments, and so on.

Recently, with the invention of clear resin and the development of 3D printers and CAD software programs, attempts are being made to print clear aligners directly. The directly 3D-printed clear aligner does not need intermediate models, and the shape and thickness of the aligner can be adjusted depending on the shell parts by software. There are many advantages, such as saving time, cost, and workflow, relieving environmental problems, simplifying the devices, and increasing mechanical efficiency.

In this presentation, I would like to introduce directly 3D-printed modelless clear aligners, their properties, and the clinical cases treated with them.