Automated process to trim and finish clear aligners

P

perfectalign

New Member
Hi,

Is there anyone that knows a setup for trimming and finishing clear aligners onces they have been thermoformed on printed models? Maybe with CNC or laser equipment. There needs to be a predefined cutting line I guess that is 2mm above the gingiva.

Hope to hear thanks!

Jesse
http://www.perfectalign.com
 
rkm rdt

rkm rdt

Well-Known Member
Full Member
Why not make the base stop at desired length of the aligner and slice the material off at that line?

Why do you have to print past the aligner?
 
CoolHandLuke

CoolHandLuke

40% titanium
Staff member
Full Member
Why not make the base stop at desired length of the aligner and slice the material off at that line?

Why do you have to print past the aligner?
i would guess you do, to demonstrate that you finished it 2mm above the ging.

seems pretty redundant to me though.


i would think you can trick modelbuilder into creating a pretty tiny model, and then use that as a suckdown guide, and just hot knife it.
 
Teofil

Teofil

Member
Full Member
Hey
I produce aligners using 3D. There are a few things you need to consider.
First of all, printed models have to have a flat base however "tiny" you print them. You can't thermoform if it's not stable or has undercuts. Since not all teeth are always at equal height their "neck lines" height also differ. You can't cut aligners following exact neck-line since every sharp angle will be a week spot and aligner will most likely break. The proper way to cut aligners is following a contour line 1mm above neck-line, with no sharp angles.
I assume you would like to automatize the part of a process after you use your pressure thermo forming machine like Biostar or similar. To do this you need 3 axis CNC mill. CNC mill "feeds"on numerical code provided by the software , i tells the burs and model holder where to move relevant to each other in space.
The main problem with this is that you can not use the same cutting path for different patient since every jaw(set of models) is unique. The cutting path is drawn in cnc router software, but you have to keep in mind that this line's position in 3D space has to be set in relation to the edge of blank thermoplastic sheet. Also because of this every 3D printed model in the whole set of models has to be set on precisely same position on the forming platform.
If you don't understand what I'm trying to say I can make you a crude drawing since my technical drawing skills are pathetic :)
 
rkm rdt

rkm rdt

Well-Known Member
Full Member
Models can be printed with a porous material to improve vacuum forming.
 
Betalab

Betalab

Member
Hi,

Is there anyone that knows a setup for trimming and finishing clear aligners onces they have been thermoformed on printed models? Maybe with CNC or laser equipment. There needs to be a predefined cutting line I guess that is 2mm above the gingiva.

Hope to hear thanks!

Jesse
http://www.perfectalign.com
Hey Jesse, your web site shows awesome aligners, how did you get those? How did you finish them? Have you seen " clear corrects" YouTube video.?
It shows from virtual setup to model printing to thermo form to cutting. I can appreciate that gingival heights are different and hence its not as simple a straight cutting or manipulating model builder.
Tell me what you find out plz :) Patrick
 
S

sriraman thiyagarajan

New Member
Hey
I produce aligners using 3D. There are a few things you need to consider.
First of all, printed models have to have a flat base however "tiny" you print them. You can't thermoform if it's not stable or has undercuts. Since not all teeth are always at equal height their "neck lines" height also differ. You can't cut aligners following exact neck-line since every sharp angle will be a week spot and aligner will most likely break. The proper way to cut aligners is following a contour line 1mm above neck-line, with no sharp angles.
I assume you would like to automatize the part of a process after you use your pressure thermo forming machine like Biostar or similar. To do this you need 3 axis CNC mill. CNC mill "feeds"on numerical code provided by the software , i tells the burs and model holder where to move relevant to each other in space.
The main problem with this is that you can not use the same cutting path for different patient since every jaw(set of models) is unique. The cutting path is drawn in cnc router software, but you have to keep in mind that this line's position in 3D space has to be set in relation to the edge of blank thermoplastic sheet. Also because of this every 3D printed model in the whole set of models has to be set on precisely same position on the forming platform.
If you don't understand what I'm trying to say I can make you a crude drawing since my technical drawing skills are pathetic :)

Hi....,

Is there any specific brand CNC milling machine is there...? Or we have to customize it...? Kindly elaborate... Because i am struggling so much in this regards....
 
JKraver

JKraver

Well-Known Member
Full Member
This seems like more work and time than the conventional method.
 
brayks

brayks

Well-Known Member
Sponsors
Full Member
Please give me a shout if you are still looking for a solution as we have developed a system for trimming aligners utilizing our Versamill 5X200.
 
A

Angelo983

New Member
Please give me a shout if you are still looking for a solution as we have developed a system for trimming aligners utilizing our Versamill 5X200.
Hello im Angelo form italy im also interested in find a milling machine for the aligner production, would be possible for you to share some information about how the Versamill 5X200 can finish them? thank you.
 
brayks

brayks

Well-Known Member
Sponsors
Full Member
Hello Angelo,
Relative to our solution, we have a solution that is quite effective for trimming aligners which allows for an aligner to be trimmed by our 5-Axis Versamill 5X200 in less than 30 seconds with high quality trim edges.

5-axis toolpath is absolutely required to trim aligners. 3-axis machining, as previously mentioned will most definitely not do the job.

This 30 second cycle time includes manual loading by an operator who's function is to scan an identifier on a model, load the model w/aligner onto a custom fixture onto our machine, and hit the start button. The solution works with a customers infrastructure to automatically download all associated programs for each aligner "case" which are then processed each time the operator removes the previously machined aligner, places the next model/aligner onto the machine fixture and hits the start button.

Programming of the machine is done as a black box module whose input is the model and associated trim-line. From that information, NC code is automatically generated and stored on the customer server. These NC, machining programs are the ones that are automatically identified and sent to the machine when the operator initiates a "batch" of aligners to be machined.

We also can automate this solution with a simple 4-axis robot which rides on a rail and can service multiple machines, thereby eliminating manual case identification, loading and unloading and operation initiation (image and videos provided).
32696
Our solution to date requires the trim-line to have been previously developed by a 3rd party application and supplied to us for processing.

This is the missing link in our "complete" solution that we are working to resolve. At this point we have a path to get this done in the coming months. Having this as part of our solution would enable us to provide a complete, single source solution to a market that has a very limited number of sources that can provide what is needed.

That said, our solution for trimming is solid and in production for installations that can provide us the trim-line(s).

Just to provide you an idea of how the, what I call "semi-automated" process works (manual operator load/unload) works, here is a link to a PDF file that provides some basic information: https://www.dropbox.com/s/khri8vh3vmhivfx/GenericAlignerTrimmingProcess.pdf?dl=0

Also to facilitate the process we fabricate a fixture for the thermoformer and our machine that includes orientation features. Each aligner model has the identical orientation features printed on the base of the model. This assures easy load as well as positional accuracy.

Please send me a PM if you would like to discuss this in more detail.
 
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