Dental arches with Form 4

I have been printing dental arches for in-house aligners and retainers since 2017. Started with one Form 2, and quickly added another one to keep workflow from backing up. I then added a Form 3 to the mix about 4 years ago, and it became my go-to printer because of less maintenance (I hate cleaning the mirrors in Form 2) and better speed. I do not print splints, restorative dental models, dentures, surgical guides, or any other resin that would be biologically approved for intraoral use.

I bought a Form 4 a year ago, and wanted to share my experience with other dentists. A phrase to summarize my experience…:”Ain’t no going back!” (If you aren’t from Dixieland, maybe AI can translate that for you). The Form 4 is now my main printer. Still use the Form 3, but less often. The Form 2s will be buried in the landfill, unfortunately, along with dozens of my outdated computers.

I was happy with my Form 3 and two Form 2s, but I bit on purchasing the Form 4 based on 1) the promise of significant reduction in print time; 2) the lower cost of resin cartridges. I did a little math, and determined the reduction of resin costs would pay for the Form 4 in a couple of years.

I print solid models flat on the platform. I use Gray V5 with the Form 4, Gray V4 with the Form 3 (which I still use in my satellite office). I tried Fast Model resin a few years ago, but reverted to Gray V4 because the models were less brittle (I give patients their retainer models for replacement retainers down the road; Fast Model resin prints were brittle and would often break if the patient dropped them. It takes a hammer to break solid Gray models). I print at 160 microns on the Form 3 (for reduced print time), and 100 microns on the Form 4.

The Form 4 speed and quality far surpasses the Form 3. To print 8 models on Form 3 typically takes 3.5-4 hours. The Form 4 can print 10-11 models at less than 1 hour. The surface finish for the models is beautiful, a noticeable improvement from Form 3 models (at 160 microns). The surface finish difference doesn’t matter clinically, but I like the better esthetics none the less.

Post-processing note – Being a tightwad, I use the manual alcohol buckets, dry the models on a cheap cardboard lunch tray in front of a cheap fan, then finish them in a MelodySusie nail lamp ($35 on Amazon) for 30 minutes. All my staff know how to do each step of the post-processing, so workflow is no issue.

Clinical note – I print solid models because of the strength factor, and because solid works better on my low-tech thermoplastic vacuum machine. Hollowed models would save more money in resin costs. Print times on the Form 4 won’t significantly lower.

I have now printed 50 resin cartridge worth of prints with the Form 4. I am more than halfway there in paying for the machine based on reduced resin costs. Have nothing but superb experiences with the Form 4.

I hope my experience helps other dentists who are considering the purchase of a Form 4.

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Hello - I am just wondering if you can answer a question or two for me

Using the fast model resin on your Form 4. Have you experienced or had higher chance of your dental models having layer lines/missing cusps vs grey resin v5 (have you tried the model resin?)

I have aligned my build platform after chatting with support, but wondering if its the resin choice totally, where I need that detail for aligner/retainer models, but the fast model resin still has layer lines (at the most detailed features layer height?)

Just wondering if by using the grey resin, what are your print times like for a full print plate? Are you printing your aligners vertically with supports ? I find I have to add immense amount of supports vs what I could get away with on my Form 3

Any insight would be greatly appreciated

Thanks
Hanna