Duplication distortion

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Aditia KT

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Hi everyone.
I have issue that maybe often happens in most removable lab
The problem is distortion in duplication model
When we do removable like acrylic denture or thermoplastic denture, we need to duplicate the master working model with alginate or pvs, and then use the duplicated model for processing the denture, but sometimes the results going wrong. The denture sometimes really cannot fit to the master model that we duplicated before.

So im thinking for solving this problem by using 3d printer, so i scan the master model and i print it using phrozen TR 250LV high thermal resin. And then use the 3d model for processing the denture (boling out the wax and then packing/injecting the acrylic/thermoplastic)

What do you guys think ?

I attach the resin physical properties
 

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sidesh0wb0b

sidesh0wb0b

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process on the master, seat on duplicate for verification.
i would advise against processing on the 3d model but thats just me
 
TheLabGuy

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Your printed model won't hold up or even melt at thermoplastic injection temps. Use a putty to duplicate or invest in a duplication machine then you don't have problems.
 
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Aditia KT

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Your printed model won't hold up or even melt at thermoplastic injection temps. Use a putty to duplicate or invest in a duplication machine then you don't have problems.
I use putty too but sometimes a huge distortion might exist, what do you mean by duplication machine ? Agar machine ?
 
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Aditia KT

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process on the master, seat on duplicate for verification.
i would advise against processing on the 3d model but thats just me
Hmm okay thanks for the advice, so my customer will get the denture on 3d printed model.
 
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Aditia KT

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Your printed model won't hold up or even melt at thermoplastic injection temps. Use a putty to duplicate or invest in a duplication machine then you don't have problems.
Yes i am afraid of the thermoplastic temperature.. if heat cure acrylic i think it will be fine..
 
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Denture Dude

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I duplicate my masters using hydrocolloid (reversible agar, others names). Personally I process on duplicate and finish to master.
 
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Aditia KT

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I duplicate my masters using hydrocolloid (reversible agar, others names). Personally I process on duplicate and finish to master.
But as i know, duplicating with agar can only special phosphate-bonded investment for partial frame denture, i tried using gypsum type 3 and 4, they cannot set...
 
JKraver

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Does your resin bond to the 3d printed model? If yes, that would be awful. If no, are their undercuts? Will the model break or the denture break first?
 
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FASTFNGR

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Hi everyone.
I have issue that maybe often happens in most removable lab
The problem is distortion in duplication model
When we do removable like acrylic denture or thermoplastic denture, we need to duplicate the master working model with alginate or pvs, and then use the duplicated model for processing the denture, but sometimes the results going wrong. The denture sometimes really cannot fit to the master model that we duplicated before.

So im thinking for solving this problem by using 3d printer, so i scan the master model and i print it using phrozen TR 250LV high thermal resin. And then use the 3d model for processing the denture (boling out the wax and then packing/injecting the acrylic/thermoplastic)

What do you guys think ?

I attach the resin physical properties
You always use the master and never the dup. Use hydrocolloid to duplicate only. It is a much more accurate and cheaper the both.
 
Doris A

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You always use the master and never the dup. Use hydrocolloid to duplicate only. It is a much more accurate and cheaper the both.
We use hydrocolloid to duplicate as well, but we process on the duplicate and seat the partial on the master. If need be, we can say to the Dr. " It fits your master model"
 
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Denture Dude

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But as i know, duplicating with agar can only special phosphate-bonded investment for partial frame denture, i tried using gypsum type 3 and 4, they cannot set...
There are multi purpose hydrocolloids out there. I use wiro gel M. Duplicated thousands of models w it.
 
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Denture Dude

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There are multi purpose hydrocolloids out there. I use wiro gel M. Duplicated thousands of models w it.
Also, I assume you understand there’s often quite a bit of acrylic finishing that has to happen before it will fit the model. Duplicate or master.
 
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Denture Dude

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Here we go
Maybe what’s the deal is here is model duplication quality. My appliances fit perfectly to my master models after finish. Sooo. I guess that means the dup model was accurate af? Let’s say we do it your way. And for some reason the partial doesn’t want to fit the duplicate during finishing. Now what? We have no master model, no way to chase down the problem. We’re gonna have to settle this once and for all. Lol.
 
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Denture Dude

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Also I’ll add, sometimes with too many opposing tissue undercuts you’ll never get it to fit a stone model.
 
Doris A

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There are multi purpose hydrocolloids out there. I use wiro gel M. Duplicated thousands of models w it.
That's what we use as well. Very accurate duplicate models.
 
kimba

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I survey and blot out undercuts in wax then duplicate in silicon. I use this model for clasps, setups and processing. Then fit to master. If you want ed to you could even send the master out for tryins . This way I always have the original , and with silicon , keep the mould till the case goes out , so if any absolute disaster you at least have a way to repour a model .
For chromes , I just take the acrylic spacer off the surveyed model , then duplicate thisfor processing. This also eliminated the undercuts from my processing model andthey snap right on the master when finished
 
Denturion

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No matter how long i let models soak in water i get small bubbles when i use hydrocolloid.
All i can imagine is that Maybe its too hot when i pour. An alginate impression is not as acurate to the master as id like. Hydro is the closest.
 
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