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HELP! Valplast !!

Discussion in 'Removable' started by rebeccaterp, Feb 4, 2009.

  1. rebeccaterp

    rebeccaterp New Member

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    My husband opened a dental lab approximately a year ago. He has been trying out Valplast for a while now, and even went to NY to take a class (we are in Oklahoma)
    Today, NOTHING seemed to go right-
    Anyway- he is at his wits end, and there is nothing I can do to help, but try and find someone else who has an answer.
    This is what I know:
    lately, there has been an issue with an open vertical after injection...?!?!

    I so appreciate any Valplast experts that might be able to pass along information!

    Thank you, thank you, thank you!
  2. DMC
    No Mood

    DMC wheeeeeeeee!!! Donator Sponsors

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    Call Jerrard at Flexi-Dent in Richmond VA. Super nice guy, who does nothing but that stuff allllllll dayyyy loooong.

    Just google it. (Maybe in Midlothian VA)


    Scott
  3. JohnWilson

    JohnWilson Moderator Staff Member

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    A few things to check for

    1) When the set up is transfered to the dup model for processing the dup model is not articulated and the occ is not verified. We double index the mounting so we can use one articulator for both casts

    2) When investing the case you are using runny lab stone instead of the recommended low expansion stone. It's not just the expansion that kills you but the teeth can actually compress into the soft stone and cause the bite to open. Die stone will solve this issue but it's a bitch to divest.
  4. Brian

    Brian Member

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    1) When the set up is transfered to the dup model for processing the dup model is not articulated and the occ is not verified. We double index the mounting so we can use one articulator for both casts



    John,

    That is solid advice for any case involving a duplicate model.
  5. rebeccaterp

    rebeccaterp New Member

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    thanks everyone, for your advice...i am here with him now- he has been in the lab for 12 hours- used the harder stone- and it is still not working right- he is frustrated beyond belief - has even mentioned taking up farming... :O(
    does anyone know of a seminar he might be able to take on perfecting valplast? if this continues, he will likely throw in the towel, and it has been one short year of opening his lab doors...
    thanks-
  6. labdude

    labdude Senior Member

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    Do not let him quit.
    Success doesn't come easy. I have no clue about your problem other than this, every part of dental tech work involves a bit (sometimes a lot) of beating your head against a wall. It can be tough, cool down, learn from what you have done, move on.
  7. labdude

    labdude Senior Member

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    Also.....get your husband online here.
  8. CShof

    CShof Member

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    I'm just curious, how much is it changing? Is it consistently off by the same amount every time? Does it vary? Can you measure it? Maybe a picture?
  9. JohnWilson

    JohnWilson Moderator Staff Member

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    Sorry he is having issues, I took the class to become registered in New York just like your hubby did, it was informative but the real world teaches you the tricks to make the stuff work.

    When is he having the largest VDO opening? Is it on free end cases? Is it more on uppers or lowers or no difference? Is it consistent on every single press?

    Has he reread through the manual to see if he is doing everything by the book every singe time?

    Its hard to know whats going on with out watching him do his work step by step, I will tell you this problem is frustrating but is not common with this material. Its very rare for us to have to spot in a bite anymore than just a minor equilibration.
  10. rebeccaterp

    rebeccaterp New Member

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    I appreciate all of your responses! This John- the husband lab tech that is experiencing the vertical issues with Valplast. Both castings are indexed and mounted to the proper vertical, so no changes are occuring in respect to the transfer to the duplicate. Die stone is used during the investment stage and it is actually a harder stone than val-stone. I have used non-stick cooking spray and motor oil on the flasks- still no change.
    I have followed the book step by step; and that is what frustrates me- you'd think following the directions would make it consistent. Whats funny is even when I went to New York the tech at Valplast saw me do every step and there still were problems.
    It is a consistent 2 to 2.5 mm on every injection. Its not just that the teeth are in higher occlusion- the material also becomes thicker. I use the pre-formed wax patterns and after injection they are at least 1 to 1.5 mm thicker than when waxed up. This is the other clue that leads me to believe it is happening during the injection cycle.
    The other problem I've been having is the flow of the material. There has been difficulty having the material flow into the anterior and bicuspid saddle clasps, and also on the palate. Its like the material hardens before it flows all the way around and into every crevasse. I've been told to add more seperator or that I've put too much on. The investments are cool when its applied and dry when injected-I've even waited three hours after. I've called a few other labs, and they have the same issues and they tell me to set each case with 1.5 mm gap between occlusal surfaces and just count on the vertical to open. I dont want to have to do that. I want the quality of my product to be unsurpassed. If there are any more ideas I am willing to try anything!
  11. JohnWilson

    JohnWilson Moderator Staff Member

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    Wow how frustrating, we do not use the wax from Valplast and we do not experience what you are describing. What heating chamber do you have? The old non digital one with the thermometer sticking out the top? Or the new digital one? Have you check to make sure the furnace is at the proper high temp and is consistent? Use a new thermometer to verify and adjust if necessary.

    The incomplete pressing issue is due to the material cooling too fast by you not injecting fast enough or your flask is too cold, or a combination of both.

    We do not set the cases up out of occlusion, the only way you can have dimensional changes in thickness is by using an investment (stone ) that is not replicating the pattern. If you gauge the thickness of the palate in wax and when it is pressed its thicker it's telling you the mold you made is not accurate. Seems you need to control the expansion of the investment material from a pure scientific background.

    If you have not bought a digital timer do so. After the oven gets to temp with the cartridge holder inside let it heat soak for at least 15 mins before putting the cartridge in. Use a good spray silicone inside the cartridge holder and make sure it is perfectly clean before you put it in the oven. Set your timer and be prudent to press at the specific time that is recommended for the size tube you are shooting.

    Back to the flask, we do not shoot into a cold flask. We do not use cynoacralate (superglue) to lute loose teeth into the mold. The heat reacts with the glue and can cause some real weird side effects. The val cement is rubber based like the old rubber cement we used is primary school. We paint our separator when the flask is warm and allow it to dry. We have a heat lamp that keeps the flask warm not HOT. We also do a tri spru rather than the y sprue as recommended by Valplast the third branch runs up the palate to the ant on max cases and to the center of the ling plate on lowers. We often connect clasps with a very thin gauge runner like a vent. Picture a case where you are clasping 22 and 27 and the partial is free end. We will use an extremely thin vent off each clasp to connect back to the ling plate at the direct center.

    One trick we found is to control moisture in the flask by not closing it till 30 secs before you press. Not sure it makes a difference but we feel we can keep the flask a more consistent temp under the heat lamp this way. We also do not release the tension on the press for 20 minutes after the press. If you are doing multiple pressing this can really slow things down but we get less warpage this way. Also make sure you abide by the warm up on the oven again and the heat soak on the next pressing if you are doing multiple units.

    Ok thats a bunch of info, I am certain you are probably just missing something simple but I remember how frustrated we were with miss pressed units in the beginning. The material really is technique sensitive but once you dial it in it's a wonderful product for our arsenal.

    Good luck
    Last edited: Feb 7, 2009
  12. Al.

    Al. Well-Known Member

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    Ditto, Coming from a C&B perspective it sounds like a expansion problem.
  13. deleon24

    deleon24 Creating God Like Smiles!

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    Open bite!

    I have discovered a great way to keep the open bite to a minimul simply after you pour ur second half using regular stone instead of expensive die stone and also hard to break out hoping not to brake teeth, simply open ur presure pot empty the water out and as soon as u invest the second half place in the presurre pot at 20-30psi until the stone sets I use slurry water so it is ussualy 5 min u will notice the stone shrink inwards but thats ok dont worry,then boilout as ussualy, then what I do after boil out is complete I soak the models in warm water for 10 min then apply separator and inject in ur usaul matter and let me tell u your problem will be solved. Hope it works for u!!! O what happens is that stone expands by puting it under presure from ur pressure pot it prevents this from happing so no open bites ever again.
    Roberto
    Deleon Dental Lab
    Houston Tx
  14. nickate

    nickate Member

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    Seems like a lot of work...
    Last edited: Oct 13, 2010
  15. araucaria
    Relaxed

    araucaria Balanced Staff Member Donator

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    Rushing may be the cause of the problem.
    IMO the stone needs time (long time) to set properly (and cool) and to be able to go through its natural metamorphosis, if the flask is opened or unscrewed before the complete setting process then problems surely follow.
  16. CYNOSURER

    CYNOSURER Can't reMember

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    I think you got it right the first time. Stone shrinks and becomes denser.

    So, what is the purpose of the 10 min soak? Is this part of the pressure technique or just your regular seperator application technique? Do you let it dry before applying the seperator? What seperator are you using?

    Do you inject into the warm flask or room temp?
  17. Flippercentral

    Flippercentral Active Member

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    I have the same questions. I like the idea of investment stone setting up in pressure pot and think I'll try it but might put flask in ziplock freezer bag before immersing in pot.

    Michelle
  18. JohnWilson

    JohnWilson Moderator Staff Member

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    Michelle,

    He is using the pressure pot as a pressure vessel with No water in it. Its an old trick we have used with investments for years. If you really want to spend some money look for a BEGO chamber for similar results at 20 times the cost :)

    As for high bites with valplast its surprising to me that his use of slurry water is not effecting the expansion of the stone but what ever works for you.
  19. Flippercentral

    Flippercentral Active Member

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    Well, I was kind of wondering that too as I was reading fast and thought he filled the pot with slurry water LOL!!! :) Seems like I remember from a book I read long ago that you could put a bowl over your investment ring and get something similar (I'm sure I'm leaving a detail out!)
  20. deleon24

    deleon24 Creating God Like Smiles!

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    The reason I soak the model flasks for 10 min is becuase the stone gets hydrated and when you inject the material u will hear a hizzing noise of the water its water vaporating from the stone not to worry then when u break it out u will notice a clean separation between the stone and the material I guess the hydration prevents the hot material form soaking up stone, also they come out vary less dull looking and more transparant. I use APS Acrylic & Plaster Separator from DVA I put it on after I soak the models in warm close to hot water not boiling hot water, let it set about 3 min and inject while the flask are still warm I know Valplast says cold flasks but I ve never had succes with it cold and I inject Duraflex, TCS, Luster-Flex, and Flexite and they all state warm flasks so I dont know why Valplast says cold. The use off slurry water has no effect on verticle dimension atleast not for me but it could be becuase I presure pot it (with out water in the pot of course). I also when flasking dentures here is another tip after you pour the second half of the flask put under the big boy press and tighten it, and watch no change what so ever in vertical dimension when u put the dentures back on the flask, again u prevent expancion of the flask to open during stone setting. And believe me its not much work at all !! Since the use of slurry water in ur investing u cut so much time and since u soak the flasks in water the separtion from the cast and the cleaness of the appliance finishing and polishing is cut by half try it and you'll see if sceptical do a trial apliance hey it works wonders for me.

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