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Un-cemented crowns

Discussion in 'Dental' started by londoner, May 31, 2008.

  1. londoner


    May 31, 2008
    London, England
    Hi everyone,

    I tried in a full gold crown on a mandibular first molar last week but was unable to remove the crown for cementation and was advised by a tutor to leave it be. However it was recently pointed out to me that this may be a potential problem when I present this patient as my finals case :scared:

    I am aware that having parallel sided walls aids in retention however as the
    crown cannot be removed at all I presume that there is no other reason
    other than I have created an undercut in my preparation? Or are there any other reasons?

    Apart from the crown being dislodged from the tooth are there any other
    long term complications associated with not cementing the crown? I was
    informed that cements are bacteriostatic and caries may develop under the
    crown but I don't see that this differs from the Hall technique in
    paediatrics where a stainless steel crown is placed on top of a deciduous
    carious tooth.

    Should I be monitoring the crown with a 6 month radiograph to look for
    caries developing at the margins? How much space between the crown and
    tooth still remains despite our best efforts?

    Would the preferred option have been to cut the crown off and construct
    another crown for the patient?

    Any advice, comments or recommendations for studies or research associated with this situation would be gratefully received.

    Thank you in advance for any advice give :)
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  3. aphistis

    aphistis Moderator Emeritus 10+ Year Member

    Feb 15, 2003
    hSDN Member
    I wouldn't be comfortable leaving it there permanently. For all you know, the patient could start bruxing one night in their sleep, dislodge the crown, and wake up with a painful tooth and a gold crown in their lungs. Whatever is keeping the crown from properly seating and coming off needs to be identified and addressed, and then it needs to be cemented properly. Good luck!
  4. NileBDS

    NileBDS SDNator Moderator Emeritus 7+ Year Member

    Jan 9, 2006
    I would for sure recommend doing all it takes to remove that crown. If you've tried all the crown removers you can think of, be a bit more creative ... add some undercuts to that crown and take a PVS impression.
    The great retentive features in your prep will serve your patient well (once the crown is cemented). Remember that the main purpose of most luting agents is to prevent bacterial leakage under your cast restoration (and not retention).

    I would give it another shot, and remove it at any cost. If not, not only will your patient develop recurrent decay, staining and sensitivity underneath that excellent crown in a fairly short period of time, but they will for sure need a root canal. All of this can be avoided.

    All pediatric restoration are temporary in a sense, and we work with the best science we have in that regards. Neither is true for permanent dentition.
  5. DrJeff

    DrJeff Senior Member Moderator Emeritus 10+ Year Member

    Nov 30, 2000
    Brooklyn, ct
    I've found from time to time over the years that if you need a little help getting a crown off, especially in a situation like this you can try one of 2 things that have done the trick for me.

    #1) grab a tofflemire retainer and a matrix band, REALLY tighten the band down around the tooth and give the entire complex some good rocking motions in all directions (meisal-distal, buccal-lingual, and occulssal-gingival)

    #2) Have the patient bite down into something real sticky/chewy on the crown(think tootsie roll/salt water taffy stickiness) and then open real forcefully and quick. Have them repeat this step a few times if needed.

    Bottomline, if thats a permanent crown and its on without a cement layer between it and the underlying toothstructure for an extended period of time, you're just asking for trouble, and one day in all likelyhood that crown will come off, just with the decayed mass of your supragingival prep inside of it:eek:
  6. OceanDMD

    OceanDMD Rather be fishing 7+ Year Member

    Oct 25, 2006

    Richwill crown and bridge removers. They are like a little cube of hard candy. You heat it in hot water for a minute, have the patient bite into the candy and squeeze together, wait 2 minutes. Have the patient open using a rocking motion. This will pull the uncemented crown out. If it doesn't, you are likely going to be using your highspeed and an increased lab bill.
  7. gryffindor

    gryffindor Dentist 10+ Year Member

    Feb 2, 2002
    Just an idea - put two ortho spacers in between the contacts mesial and distal to the crown. See the patient after 5 - 7 days, remove the spacers and there will be space on either side of the crown. If tight contacts are what is jamming the crown in there, it should be easier to remove it now.
  8. DrJeff

    DrJeff Senior Member Moderator Emeritus 10+ Year Member

    Nov 30, 2000
    Brooklyn, ct
    If you haven't guessed yet from the vast number of suggestions thta have popped up already, you're not the first person this has happened too;):D
  9. aphistis

    aphistis Moderator Emeritus 10+ Year Member

    Feb 15, 2003
    hSDN Member
    Spoken like an orthodontist. ;)
  10. charlestweed

    charlestweed Dentist Silver Donor Classifieds Approved 10+ Year Member

    Jul 10, 2007
    Not a bad idea. Just slide an ortho separator under the interproximal contact with 2 pieces of floss (orthodontist often use this technique to place separators on pts who have very tight contacts) and pull the separator upward…I accidentally dislodge a couple of PFM crowns and MOD amalgam fillings a few times with this technique.
    Last edited: Jun 2, 2008

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