Distortions in duplicate models

[Zojurn]

Hello,

I am experiencing distortions on my dupes. It looks as if the issue is present in the polyflex investment. However this is a problem I have never encountered before and may have more than one contributing factor. Hopefully this is a common issue that someone has already been able to resolve and can give me some tips. Any help would be appreciated.

 

[Andrew Priddy]

model didn't soak for 10-15 (degass)
bubble in the hydro pour
is it a chunk of cold hydro? not fully melted?
counter sit? or water bath? after hydro pour
how old is it or was it overheated?

that's about all we can think of... ima go with "there was no water bath".
and those look like tear lines= burned/brittle/compromised

 

[Doris A]

model didn't soak for 10-15 (degass)
bubble in the hydro pour
is it a chunk of cold hydro? not fully melted?
counter sit? or water bath? after hydro pour
how old is it or was it overheated?

that's about all we can think of... ima go with "there was no water bath".
and those look like tear lines= burned/brittle/compromised

The only thing I can add to your list is to make sure after soaking for 10-15 minutes is to use air hose to remove excess water from the model.

 

[JMN]

Pouring speed and consistancy of speed can also cause issues

 

[Doris A]

Pouring speed and consistancy of speed can also cause issues

You're absolutely right. I had a dupe do that when my machine was just about empty and was running very slow. I had forgotten about that, it was so long ago. Good to the last drop isn't always the case.

 

[JKraver]

You're absolutely right. I had a dupe do that when my machine was just about empty and was running very slow. I had forgotten about that, it was so long ago. Good to the last drop isn't always the case.

I have rubber bands set up to hold the dupe flask over my vibrator, if everything is tacked down properly it helps get the agar where it needs to be evenly. Then you need to water bath at 1/3 the height for 10 minutes then just under the top until cooled fully.

 

[JMN]

I have rubber bands set up to hold the dupe flask over my vibrator, if everything is tacked down properly it helps get the agar where it needs to be evenly. Then you need to water bath at 1/3 the height for 10 minutes then just under the top until cooled fully.

Vibration concerns me, cavitation bubbles can form.

 

[rkm rdt]

stone age

 

[sidesh0wb0b]

we moved away from polyflex, we were seeing some similar inconsistencies

 

[JKraver]

Vibration concerns me, cavitation bubbles can form.

hasnt been an issue.

 

[rkm rdt]

So this is why we process on the dupe. We can even go back to duping an alginate. How many frames were made this way? Still? How accurate is that?
The drags , pulls, and every yip becomes part of the model you work on. We get good at fixing bubbles or avoiding them altogether, yea right!
The time invested in the whole model making process is exponentially greater than the cost of an intra oral scan.
Sure there is a learning curve but reward of an accurate model to begin the case is worth it. A printed master model allows you to leapfrog many analog steps . Dupe as many casts as you want, no bubbles no troubles.

 

[rkm rdt]

So this is why we process on the dupe. We can even go back to duping an alginate. How many frames were made this way? Still? How accurate is that?
The drags , pulls, and every yip becomes part of the model you work on. We get good at fixing bubbles or avoiding them altogether, yea right!
The time invested in the whole model making process is exponentially greater than the cost of an intra oral scan.
Sure there is a learning curve but reward of an accurate model to begin the case is worth it. A printed master model allows you to leapfrog many analog steps . Dupe as many casts as you want, no bubbles no troubles.

I believe the accuracy is 50 microns.

 

[Zojurn]

I appreciate all the input. I recently started at a new lab. Some of the equipment is different than what I am used to,

The models are not static soaked with a cast conditioner. Instead they are being soaked in a open tub with tap water for 15+ minutes before investing.

The models are not being invested in a duping flask. Instead they are being invested in a glass bowl.

The investments are not put in a chilled water bath. Instead they are put in a plastic tub without cooling. Same tub the models are soaked in.

The polyflex is recycled 3 times before being changed. The machine is fully drained and all the polyflex is washed and chopped uniformly before being recycled.

I achieved better results today after looking for a few things pointed out in this thread.

The polyflex is at the end of its cycle.

I used the air hose on the model prior to investment.

Pouring speed and consistency may be part of the issue. I do my best to unblock the spout. The polyflex likes to set up and block it which does introduce inconsistencies in the stream.

I have been starting the stream in a spare bowl, letting it normalize the best I can before switching over to the model to be invested.

I have also noticed that the bowls are retaining a residue. I am now making sure they are fully cleaned.

Below are some images of the machine and work space for further context.

Thanks again for all the great replies.

 

[Denture Dude]

Looks like pouring too slow or too low of a temperature or both. The material is folding on itself. I’ve had this happen before. Very rare. Best handling hydrocolloid I’ve used has been wirogel m.

 

[Denture Dude]

Ac vent above colloid machine?

 

[Doris A]

Looks like pouring too slow or too low of a temperature or both. The material is folding on itself. I’ve had this happen before. Very rare. Best handling hydrocolloid I’ve used has been wirogel m.

That's what we use as well. Great stuff.

 

[sidesh0wb0b]

i will add to @Doris A and @Denture Dude and say we switched around to a bunch of different dupe materials before landing on Bego's wirogel and we are absolutely THRILLED with the results. havent had an issue in longer than i can recall. the material lasts longer too, better duplications, no inconsistencies (that we have noticed),and all around so much less hassle that its not even a thought anymore.

 

[Denture Dude]

Ooh. Budweiser