Ok. I am having an issue with acrylic "flash" around teeth after process.

[JKraver]

I use all stone for ivocap as well.

You use flexistone plus right? Have you tried a basic die stone instead like diekeen or silkyrock? It is cheaper and gives great results vac mix, and spatulate onto the entire wax up, pressing it into all those hard to reach places.

 

[Affinity]

I dont claim to be a removable guru, but I know several that are that clean wax from the teeth before processing. If you have a wax solvent that leaves a residue, then I would agree not to use it. White gas completely evaporates, which is what I use. I also process with putty because I dont like picking stone out of teeth, only time I get acrylic over the teeth is if the tooth shifts when flasking.

 

[JMN]

I dont claim to be a removable guru, but I know several that are that clean wax from the teeth before processing. If you have a wax solvent that leaves a residue, then I would agree not to use it. White gas completely evaporates, which is what I use. I also process with putty because I dont like picking stone out of teeth, only time I get acrylic over the teeth is if the tooth shifts when flasking.

White gas = Naptha?

 

[Affinity]

 

[2thm8kr]

White gas = Naptha?

Yes or camp stove fuel.

 

[JMN]

Yes or camp stove fuel.

Thanks!
What's your avatar pic this time? Baggage claim at O'Hare?

 

[2thm8kr]

Thanks!
What's your avatar pic this time? Baggage claim at O'Hare?

Spent emax CAD blocks.

 

[Doris A]

You use flexistone plus right? Have you tried a basic die stone instead like diekeen or silkyrock? It is cheaper and gives great results vac mix, and spatulate onto the entire wax up, pressing it into all those hard to reach places.

No I don't , I was just letting him know that option to keep stone off of his teeth.

 

[denturist-student]

I am using something called Rapid flask by Whipmix for investing...I also wipe the teeth off with a light layer of wax solvent before investing. Even finger oils can cause shifting in a tooth.....and those you cannot see........ergo I use the wax solvent.....much to JKravers chagrin....Never had any problems such as yours....The rapid flask will cure in 40 minutes. I both clean out old visible wax with the bath water and then with clean boiling water clean out again with sunlight dish soap two or three times. Pay attention to water powder ratios....Even when I use a barrier such as elite 85 shore hardness I still use the rapid flask. Not as strong as conventional stone but I never need to vibrate it at all...The intaglio is the important surface. Not the buccal or labial surface although I may raise a few eyebrows with that statement.. I even use rapid flask for the ivobase units.

 

[denturist-student]

I wouldn't use lab plaster to invest, it is simply not hard enough the stone could crush. You can thin coat with a good stone on teeth/wax and backfill with plaster/stone mix

I agree with you on that one. plaster not good enough for investing...even the base layer should be half and half mix at very least.

 

[denturist-student]

I have tried everything-- even waxing UP TO the teeth and never having to scrape or clean them off before investing as they never had wax on them to begin with-- yet this problem persists. THERE IS NO WAX REMAINING AROUND THE CERVICALS (I know, I know-- but really. I am using a magnifier to check.)
About a .75-1mm piece of stone left around the cervical edge of the teeth after devesting. You can pop it off but the acrylic film remains-- and needs to be lightly chiseled around just rubbing over it with the back side of the chisel lightly-- VERY thin skin or film... almost seems like it could be separator.
If I pull a tooth out of the flask after painting w/ separator- the separator has not leeched past the cervical edge.
Investing with Hydrocal 105 yelow stone.
I would rather not use insulating pastes or puddies.

The rundown:
Waxing up to teeth- not going over and removing- wax never introduced on to cerv. past where waxed
NO WAX SOLVENTS APPLIED
All yellow stone investing
Tried 3 different waxes- To soften the wax--tried from 5 min all the way to 10 mins to soften the wax in boil out tank. Nope.
Pneumatic press used- 4500psi and have tried down to 3100 psi thinking maybe pushing past... Nope.
Two different separators... no way
Tried bench set 15 mins., no bench set.... un-uh
Tried fast cure, slow cure- nada
3 different brands of acrylic-- no

Not passing the job off to another tech. Hands on by me.

This is frustrating. Help me MOMMA!!!!

I have used vaseline and a small bristle brush on my handpiece to get this off but be careful easy to burn the teeth. Use a slower speed. That should really help in the cervicals.and get the acrylic off the teeth.

 

[JMN]

I wouldn't use lab plaster to invest, it is simply not hard enough the stone could crush. You can thin coat with a good stone on teeth/wax and backfill with plaster/stone mix

We use 2/3 stone 1/3 plaster for investing.

I agree with you on that one. plaster not good enough for investing...even the base layer should be half and half mix at very least.

Okay, wow. I'll change, physics wins. Thanks y'all.

 

[JKraver]

I am using something called Rapid flask by Whipmix for investing...I also wipe the teeth off with a light layer of wax solvent before investing. Even finger oils can cause shifting in a tooth.....and those you cannot see........ergo I use the wax solvent.....much to JKravers chagrin....Never had any problems such as yours....The rapid flask will cure in 40 minutes.

Fewer variables fewer problems. I wont knock you for using it, I just haven't noticed it do my any good. More than one way to skin a cat.

 

[Affinity]

IMO cleaning the teeth with ivocap is a necessity, it will press into every nook and cranny. Im only going by my own failures, and cleaning the teeth prior is what eliminated flash over the teeth. Its not even up for discussion with me.

 

[Denturist]

OK.. Hi boys and girls.
It's been a long time since I have been here and you all just came to mind so here I am again.

Now about your little plaster problem in the interproximal and margin areas.
I use this http://us.shopq.ivoclarvivadent.com.../ivocron-separator-for-denture-teeth-_4x30ml_

Once your done with all the finish waxing and festooning, use a small fine point brush go around the tooth margins and over the tooth with Ivocron separator.
Let dry and invest. Ivocron dries very quickly and this whole process only takes a couple minutes...... boil out,........ add your usual separator, let dry completely, .... and process in the manner you choose.
After breakout use a medium buffalo brush in your hand-piece to quickly remove the Ivocron from the teeth and interproximal and margin areas.

 

[dborla01]

"Interesting replies concerning that thin layer of acrylic flash. I have never had this issue, but I have had issues with failure of separator. I went back to using a silicone paste before top-pour and results' are nice. Of course I finish that top-pour on the vibrator.

 

[TMLab]

I would try 30 minute bench set first and if that doesn't work, also try wax solvent to clean the teeth and then wipe the solvent off the teeth with a dry teri cloth towel. Let us know how it turns out.

 

[denturist-student]

"Interesting replies concerning that thin layer of acrylic flash. I have never had this issue, but I have had issues with failure of separator. I went back to using a silicone paste before top-pour and results' are nice. Of course I finish that top-pour on the vibrator.

Funny you should mention that. My last batch of separator had to be turfed....it would absolutely peel off during press packing....likely froze in transit.

 

[dmonwaxa]

Could it be the boilout technique?

Too short boilout time results in teeth being pulled out of sockets...usually breaking off or at least abrading the stone that locks in the teeth at the cervical. And probably more so when its pushed back in. Creating a space....for acrylic.

A boilout technique that's too long results in wax thats liquified, leaving a thin film ir not properly cleaned. If a thin film at the cervical was overlooked prior to flasking, then a space will exist after boilout and filled with acrylic during packing.

My 2 cents

 

[budgenator]

Many will think I'm being persnickety, I recommend you never ever place a closed flask with wax in boiling water period. Wax expands as it melts, if the flask is closed the molten wax may expand into the tooth-gypsum interface, which also leads to acrylic expanding into the same area.
Here's the way I do it.

1. Very Lightly grease flask with high temperature disk brake wheel bearing grease (not compatible with Molloplast B or probably any other silicone).
2. Separate working model with a liquid soap separate, (I use N-Sep but even Ivory hand soap works)
3. First pore half dental plaster (type II) and half Stone (type III) I use Modern Materials lab plaster and denstone but Whipmix stones are quality products too.
4. After initial set polish the gypsum surface with wet/dry sandpaper, dry and soap.
5. Second pore with flasking stone to top of teeth
6. Let flask rest in the compress to get good metal to metal contact on the flask parts until initial set is achieved
7. Soap the top of the second pore and make 3rd pore with stone and gypsum slurry then close flask.
8. Place flask in cool water, not covering the top of the flask to sink the heat from the second pore going into the exothermic phase for 15 minutes.
9. Transfer flasks to 125 F, (51C) for a 20 minute heat soak, tweak temperatures to match your waxes, you want them softened and slightly gelled, not melted
10. Remove as much as you can by hand, then flush the rest of the wax off with boiling water.
11. Heat soak in boiling water for at least 5 minutes, flush with boiling water, scrub with dilute Dawn dish detergent (I dilute 1:32),rinse with hot water.
12. Bench cool until dry and apply acrylic separator per directions, I've fallen in love with DVA's APS, Acrylic & Plaster Separator!

Using this method I've never been surprised by acrylic flash on the teeth, when it does happen the flashed tooth has been moved and ground numerous times and I pretty much expected it.