Accuracy is the name of the game with dental 3D printing. Precision models like biocompatible surgical guides, splints, fixed patterns and dentures have to be made to an exact specification as outlined in CAD to be usable, which is why the consistency and reliability of a 3D printer is so important.
Formlabs has been at the forefront of dental 3D printing for several years. Stereolithography (as we saw with the Form 2) is capable of producing models that are highly detailed with minimal support structure.
With SLA, it’s possible to print splints, retainers and other orthodontic devices – as well as models that have removable dies – in the dentist’s office to an accuracy equal to or greater than with milling.
However, SLA isn’t perfect. With the Form 2, massive peel forces meant intricate, detailed dental models were at a higher risk of failure. Peel forces are the biggest disadvantage of inverted SLA because they limit the types of design that can be made. What this means is that while it’s perfectly possible to make beautiful dental models with SLA, there are design limitations brought about by peel forces which affect the print as it separates from the surface of the tank.
Low Force Stereolithography
The solution is Low Force Stereolithography, a proprietary technology which Formlabs’ created to significantly reduce peel forces. It utilises a flexible resin tank which bows gradually as the part is lowered, which reduces the pressure on parts and allows for light-touch support structure. This also has the benefit of increasing both print success rate and repeatability for a better 3D printing experience.
It’s important to note also that the Form 3 and 3L use a Light Processing Unit (LPU) which delivers linear illumination. The illumination is controlled via an optic system containing a system of lenses and mirrors. The laser beam is directed through the optic system, passing through a spatial filter before reaching the platform.
The Formlabs Form 3B
But Formlabs weren’t finished there. In November 2019, they launched their first ever 3D printer optimised specifically for dental — the Form 3B.
The Form 3B is designed for dental professionals to be used in a dentist’s office or dental lab. It utilises a tweaked version of the Low Force Stereolithography (LFS) technology found in the Form 3 and Form 3L. Here, it’s called Advanced Low Force Stereolithography and it has a custom-designed light engine for greater model quality.
It functions in much the same way as the LPU in the Form 3, however the custom light engine in the Form 3B moves the laser even more smoothly and consistently across the build volume for unrivalled accuracy. This makes a massive difference in final part quality, especially when printing biocompatible resins.
It can print the following dental models:
– Crown and bridge models
– Clear aligner and retainer models
– Diagnostic models
– Surgical guides
– Occlusal splints
– Patterns for casting and pressing
– Dentures with 4 base and 6 tooth shades
The Form 3B is designed for dental applications and it comes preloaded with print settings for the complete Formlabs Dental Resin collection.
In particular, the Form 3B is designed to produce dimensionally-accurate implants, guides and templates from biocompatible resins like SG Resin. Traditionally, these resins are more difficult to print successfully with regular SLA. Advanced Low Force Stereolithography is a massive leap forward with regards to this – the combination of reduced peel forces and that custom light engine mean a far greater success rate.
Designed for dental modelmaking for crowns, bridges, implants and orthodontic models. Suitable for removable dies.
Surgical Guide Resin
An autoclavable, biocompatible resin for dental surgical guides, drilling templates and pilot drill guides.
Dental LT Clear Resin
A long-term biocompatible resin for functional models, including splints and occlusal guards. Transparent and high optic.
Castable Wax Resin
A high-performance dental resin for casting and pressing crowns, copings, substructures and partial denture frameworks.
A dental resin for prototyping and model making. Suitable for making highly detailed orthodontic and aligner models.
Build Volume and Features
The Form 3B has a build volume of 14.5 × 14.5 × 18.5 cm (5.7 × 5.7 × 7.3 in) which is the same as you get with the Form 3. The difference comes in the optimised light engine, which is designed specifically for dental resins.
At 5.7 × 5.7 × 7.3 in, the Form 3B’s build volume is sufficient to print a series of dental models in one sitting. For example, here’s a tray of dental models that were printed in one go using the Form 3B:
Importantly, the Form 3B is designed to run 24/7 without supervision. You can press print and leave it to do its job.
Also importantly, the Form 3B has user-replaceable components. The LPU, rollers, and optics window are user-replaceable, and the resin tank can be swapped out in seconds thanks to its cartridge system. By making these components user-replaceable, Formlabs has increased the uptime of its 3D printer.
The Form 3B is exceptionally easy to use and get the most out of. You can collect patient anatomy digitally using an intraoral scanner and then import that scan data into CAD. CAD files are then imported into PreForm, which applies the correct print settings and sends the print job to the Form 3B.
At the front of the printer, there’s a 5.5″ interactive touchscreen with a 1280 × 720 resolution, through which you can control the printer and print job. There are also LED status indicators so you can see what’s happening at a glance. You can also manage prints and printers via the cloud and set up SMS and email alerts.
You’ll use PreForm software a lot in your workflow and the good news is it’s one of the best programs of its type. It has the following useful features: one-click print, adaptive layer thickness for faster printing with fine details, remote print, auto-orient for optimal print position, auto-mesh repair, auto-generation of supports, rotate, scale, duplicate, and mirror, and a layer slicer for path inspection.
Overall, the Form 3B is a dream to use from the moment you first switch it on to the moment it produces its first surgical guide. It also runs through the setup process with you on its touchscreen display when you first switch it on.
Form 3D Printer Specifications:
– Technology – Low Force Stereolithography (LFS)
– Resin Fill System – Automated
– Build Volume (W x D x H) – 14.5 × 14.5 × 18.5 cm
– Layer Thickness (Axis Resolution) – 25 – 300 microns, 001 – .012 in
– XY Resolution – 25 microns, 0.001 in
– Laser Spot Size – 85 microns, 0.0033 in
– Supports – Auto-Generated, Light-Touch Removal