• Welcome to Dental Lab Network
    1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

    Printed model inaccuracy

    Discussion in 'Dental-CAM' started by subrisi, Dec 19, 2016.

    1. subrisi

      subrisi Member Full Member

      Joined:
      Aug 2009
      Messages:
      396
      Likes Received:
      5
      I am having fit issues with printed models. We are used to re-wax all the margins of our milled wax crowns, but now since we are doing printed models from a carestream scanner, we get crowns back with open margins. I assume that by waxing the margins to the printed die, we are creating "hold up's" and the crown does not seat. I can't get myself over it to leave the margins untouched and ignore toe wide open space. How do you deal with that and what might be wrong with the system?
      Angelika
       
    2. PDC

      PDC Active Member Full Member

      Joined:
      Mar 2011
      Messages:
      736
      Likes Received:
      110
      Are you printing them or outsourcing?
       
    3. JMN
      No Mood

      JMN Christian Member Donator Full Member

      Joined:
      Sep 2012
      Messages:
      3,350
      Likes Received:
      620
      Just a thought, have you tried designing and delivering completely model-less?
      The model creation process adds another family of variables of which you have no control and many times no knowledge(unless you are *really* close with your model supplier). It may be that the scanned data is accurate enough to produce a properly sealing crown, but the model fabrication is not.
       
      • Like Like x 1
    4. CoolHandLuke
      Fiendish

      CoolHandLuke Well-Known Member Full Member

      Joined:
      Aug 2011
      Messages:
      5,266
      Likes Received:
      761
      this is the more likely scenario.
       
    5. JMN
      No Mood

      JMN Christian Member Donator Full Member

      Joined:
      Sep 2012
      Messages:
      3,350
      Likes Received:
      620
      Thanks! I was just throwing a logic shark at the pool and that's what it ate.
       
      • Like Like x 1
    6. CoolHandLuke
      Fiendish

      CoolHandLuke Well-Known Member Full Member

      Joined:
      Aug 2011
      Messages:
      5,266
      Likes Received:
      761
      what do you think i do when it comes to remote troubleshooting like this?

      this helmet aint just to hold my giant ego you know.
       
    7. JMN
      No Mood

      JMN Christian Member Donator Full Member

      Joined:
      Sep 2012
      Messages:
      3,350
      Likes Received:
      620
      Nah, there's lots of straps and padding in there too in case someone pulls the emergency brake when you've gone to plaid.
      Plus, you've gotten experience with a lot more of these toys than I have.
       
    8. CoolHandLuke
      Fiendish

      CoolHandLuke Well-Known Member Full Member

      Joined:
      Aug 2011
      Messages:
      5,266
      Likes Received:
      761
      i mean alternatively its very easy to say 'yeah your die spacer was applied incorrectly' or 'whoever is milling your wax doesn't seem to have a great grasp of how digital design and milling should mesh together'

      this seems too easy though. and i like to give the benefit of the doubt whenever possible, until it irreducibly points in this general direction.
       
      • Agree Agree x 1
    9. JMN
      No Mood

      JMN Christian Member Donator Full Member

      Joined:
      Sep 2012
      Messages:
      3,350
      Likes Received:
      620
      Yep, break the problem causing process into smaller and smaller halves until you've found the half with error producing outcome.
      I think a good tech is more interested in how to fix the problem, not the blame. Unless the problem is between the workpiece and chair and refuses to follow instructions, that you frequently can't fix.

      There is a Japanese process called something like "the 6 questions". By the time you've answered the six questions that led to an error, you will have created a documented process to prevent any step towards it's replication and will have discovered and eliminated other issues not only in that process but parallel and feeder processes.
       
    10. rkm rdt
      Artistic

      rkm rdt Well-Known Member Donator Full Member

      Joined:
      Nov 2007
      Messages:
      11,919
      Likes Received:
      2,179
      Where's the beef?
       
      • Agree Agree x 1
    11. Torquadon

      Torquadon Member Full Member

      Joined:
      Aug 2012
      Messages:
      93
      Likes Received:
      12
      I believe first question to ask is why are you rewaxing all margins on wax milled crowns? There is something wrong here, sure it sometimes happens, but it definitely should not be a rule. When you working with IO scans your scan is way more detailed than a model you print, so by assuming you are going to change margins you loosing accuracy.
       
      • Agree Agree x 3
      • Like Like x 1
    12. JMN
      No Mood

      JMN Christian Member Donator Full Member

      Joined:
      Sep 2012
      Messages:
      3,350
      Likes Received:
      620
      It was on my plate. :)
       
    13. KentPWalton
      Tired

      KentPWalton Well-Known Member Full Member

      Joined:
      Apr 2012
      Messages:
      1,567
      Likes Received:
      214
      Geez, there are so many variables here! Material settings, design settings, material, material post processing, etc. :rolleyes:
       
      • Agree Agree x 1

    Share This Page