Menu Icon Search
Close Search

About the ads

Advice for Making Temporary Crowns

Discussion in 'Dental' started by Edentulator, 08.29.10.


  1. Thanks to Crack the NBDE
  1. Edentulator

    Edentulator

    Joined:
    03.21.10
    Messages:
    40
    Location:
    Canada
    Status:
    Dentist

    SDN Members don't see this ad. (About Ads)
    My provisionals are disasters more often than not... The general technique we were taught was to make an impression of either the tooth or cast using putty or alginate. That gets filled with the temporary crown goo and seated on the prep and allowed to set. Then the temporary crown is trimmed and cemented and it's supposed to look perfect.

    My margins never line up well, and I often have patients phoning a week later saying the temporary fell off. Can anybody give me any advice on what I could be doing wrong, or tips on how to improve?

    Thanks!!
     
  2. Streetwolf

    Streetwolf Ultra Senior Member

    Joined:
    10.25.06
    Messages:
    1,803
    Location:
    NJ
    Status:
    Dentist
    Dentist SDN 7+ Year Member
    Is the "temporary crown goo" acrylic? We use that for relining (though we use pre-fabs). Have you tried putting the "goo" around the margins of the prep in addition to in the impression? That could help you get better margins and a more well defined finish line within your temp.
     
  3. UCSF2012

    UCSF2012 Tooth Rehab Student

    Joined:
    11.28.07
    Messages:
    864
    Status:
    Rehab Sci Student
    SDN 2+ Year Member
    Just use ion crown and tell your patients to not smile for 2 weeks.
     
  4. tinman831

    tinman831 ¯\_(ツ)_/¯ Administrator SDN Senior Moderator Lifetime Donor

    Joined:
    12.11.04
    Messages:
    11,312
    Location:
    Texas
    Status:
    Dentist
    Dentist SDN 10+ Year Member
    A temporary crown falling off is usually a sign that maybe the taper of your prep is excessive or that you did not keep the tooth dry prior to cementation. Try looking into this as well.
     
  5. DrJeff

    DrJeff Senior Member Moderator

    Joined:
    11.30.00
    Messages:
    2,667
    Location:
    Brooklyn, ct
    Status:
    Dentist
    SDN 10+ Year Member
    Step #1 - does your prep have adequate space for the acrylic (and later for the porcelain)??

    Step #2 - Do you have a consistent finish line on your preps that YOU understand what it's shape looks like?? If the burs you're using has a chamfer shape, and you know what a chamfer shape is, then that should help you as you're trimming the margin

    Step #3 - If you're temps are falling off after a week or so, as has been mentioned already, is your prep over tapered and/or short in height??

    When I'm making a temp, I start with a quick PVS imression of the tooth/teeth I'm prepping. Prep the tooth. Then I use an autopolymerizing polymethyl methacrylate (Integrity from Dentsply). I inject it into my PVS matrix. Wait the 1:45 per manufacturers instructions, then all that usually needs to be done is to just flick/pull away the excess flash on the magins and cement with clear temp-bond non eugenol. Less than 5% of the time will I then need to see the patient to recement the temp between when I finish that visit and when it's time cement the final crown
     
  6. mike3kgt

    mike3kgt Hopefully scuba diving

    Joined:
    07.14.04
    Messages:
    886
    Status:
    Dentist
    SDN 7+ Year Member
    Maybe your temp technique would improve if you actually knew what materials you were using instead of "temporary crown goo." I mean, I'm being scarcastic, yes, but yet also blunt.

    Proper knowledge of your materials will lend well to technique. For example, are you using a Bis-acryl? (Integrity - sorry Dr. Jeff, it's not a PMMA, it's a resin)? Are you using a Poly-methyl methacrylate resin (Jet) or a poly-ethyl methacrylate resin (Trim,Snap)?

    All have different properties that call for much different techniques for handling. Start by knowing what you're using and then you can better your technique!

    Try this article first (Christensen): http://jada.ada.org/cgi/content/full/134/5/637

    :thumbup:
     
  7. HupHolland

    HupHolland

    Joined:
    06.23.08
    Messages:
    671
    Location:
    MA / RI
    Status:
    Dentist
    SDN 5+ Year Member
    Good advice. And I'm a bit embarrassed that the OP, a DENTIST, dare call his/her temp material "temporary crown goo." Seriously?

    Hup
     
  8. DrJeff

    DrJeff Senior Member Moderator

    Joined:
    11.30.00
    Messages:
    2,667
    Location:
    Brooklyn, ct
    Status:
    Dentist
    SDN 10+ Year Member
    http://www.dentsply.com/assets/DFU/Temp_Bridge_Resin_English.pdf

    Check the bottom of DENTSPLY'S own instruction sheet. Integrity is a Methacrylate
     
  9. nuddar

    nuddar

    Joined:
    08.29.10
    Messages:
    4
    Status:
    Dental Student
    If your temporaries are falling off you also need to check for excursive contacts. You generally want the temp to have contact in MI but the excursive contacts should be minimal to non-existant. Also, did you say you use alginate to make your matrix? Alginate deforms after about 12 minutes. Use a putty matrix, vacuform matrix, pvs sectional, or blue moose impression but don't use an alginate impression of the tooth.
     
  10. Edentulator

    Edentulator

    Joined:
    03.21.10
    Messages:
    40
    Location:
    Canada
    Status:
    Dentist
    It's Integrity. Trust me, I know what I'm using and know all about it. But there's a lot more to good technique than getting an A in biomaterials, as you'll find out as you progress through dental school and run into your own challenges.

    Thanks to the others for the useful suggestions! I suspect in this case my prep was a bit short. My margins (chamfer) were smooth and continuous, and taper was probably 7-8 degrees, but I was short on interocclusal space and after reduction was left with about 4 mm of tooth structure.

    I agree that alginate isn't a great material to be using. It just happens to be what they do in the office I work at, which is why I tried it. I'll switch back to PVS in the future, which will hold its form and hopefully give me a tighter marginal seal.

    This was my first crown outside of dental school, and fourth crown ever on a real patient. The next one will be perfect, I just know! :)
     
    Last edited: 08.30.10
  11. mike3kgt

    mike3kgt Hopefully scuba diving

    Joined:
    07.14.04
    Messages:
    886
    Status:
    Dentist
    SDN 7+ Year Member
    Jeff,

    The pdf link was for "Temporary Bridge Resin" which is a PMMA, so I agree, the material you posted in the link above is definitely for a methacrylate. Go back to that page and click the "Directions for Use" on the top of the page, it is for Integrity. Link: http://www.dentsply.com/assets/DFU/Integrity_English.pdf

    I can tell from your posts that you are a good dentist and a quality operator, please do not take my previous post as condescending. It was merely to emphasize that we should know all about our materials prior to or in conjunction with knowing how to use them really well. Now knowing the chemistry is probably not necessary, but knowing the information in the Christensen article I posted above certainly will help with your clinical handling of the materials (i.e. which can you reline?, which can you brush bead with flowable composite?, which shrinks the most?, which has the highest hardness? which is the most brittle? etc etc etc.)

    Knowing these things really does matter in daily clinical practice because if your provisionalizing a single unit that is to be replaced in 2 weeks with a final crown and you want your assistant to make really quick, a Bis-acryl works fantastic (i.e. ProTemp, Integrity, Luxatemp). But say you are preparing a full arch (14 teeth) and wanting to have the patient in provisionals for 6 months while they are away on a cruise around the world and wants to be able to eat lamp chops in Greece... maybe you should consider a heat/pressure cured PMMA (i.e. Jet, C&B resin).

    Integrity is a Bis-acryl resin which, while could possibly be derived from a metacrylate, is widely considered a composite resin rather than a methacrylate. It is, however, certainly is not a PMMA.

    Also, see these published references:

    ---------------

    J Prosthet Dent. 2001 Feb;85(2):129-32.
    Comparative in vitro evaluation of two provisional restorative materials.

    Young HM, Smith CT, Morton D.

    Department of Operative Dentistry, College of Dentistry, University of Florida, Gainesville, FL 32610, USA. [email protected]
    Abstract

    STATEMENT OF PROBLEM: Provisional crowns traditionally have been associated with problems such as poor occlusion, contour, fit, and finish. Fabrication procedures should be uncomplicated and predictable within a realistic time frame.

    PURPOSE: The purpose of this study was to compare the quality of provisional restorations fabricated by dental students from 2 different materials (bis-acryl composite resin and PMMA) and identify the advantages and disadvantages associated with each material.

    MATERIAL AND METHODS: This study evaluated the occlusion, contour, marginal adaptation, and finish of 222 provisional crowns fabricated by 2 groups (A and B) of dental students. One bis-acryl composite resin material (Integrity) and 2 PMMA resins (C&B Resin and Snap) were evaluated.

    RESULTS: For group A, Integrity was statistically superior (P<.05) to C&B Resin in all 4 categories for anterior provisional crowns. For posterior provisional crowns, Integrity proved superior in the categories of contour and marginal adaptation, but no significant differences were established for occlusion and finish. For group B, Integrity was statistically superior to Snap in the categories of occlusion, contour, and marginal adaptation, whereas there was no statistical difference in finish. When all 4 categories were analyzed, Integrity was found to be statistically superior.

    CONCLUSION: Bis-acryl composite resin (Integrity) was significantly superior to PMMA (C&B Resin and Snap) as a provisional restorative material.

    -----------

    Taken from:
    Haselton DR, Diaz-Arnold AM, Vargas MA. Flexural strength of provisional crown and fixed partial denture resins. J Prosthet Dent. 2002 Feb;87(2):225-8.

    Integrity and Jet are right next to each other.

    [​IMG]

    -----------

    Great summary of materials:

    http://www.insidedentistry.net/article.php?id=1840

    -----------

    Again, not trying to start an argument or to start a fight, but the literature is clear.
     
  12. lotexigeus

    lotexigeus Master Member

    Joined:
    07.06.06
    Messages:
    424
    Status:
    Dental Student
    SDN 7+ Year Member
    holy crap, what school did you go to? only three crown requirements?
     
  13. DrJeff

    DrJeff Senior Member Moderator

    Joined:
    11.30.00
    Messages:
    2,667
    Location:
    Brooklyn, ct
    Status:
    Dentist
    SDN 10+ Year Member
    Not taken as offensive at all. If anyone was to even think that a PMMA temp crown was superior to a Bis GMA based temp crown they need to have their head examined! :laugh: You more than make up for the extra cost of the Bis GMA in chair time saved.

    IMHO, the #1 most important thing to getting a good temporary is having a very good, relatively rigid matrix to be inserting the temp material into. I personally find alginate to just be too "soft" and as a result the chances of getting significant deflection in the material secondary to essentially hydrostatic pressures when you re-insert that matrix with the temp material loaded onto that prepped tooth are too great, and that will lead to more work trimming/adjusting and a generally inferior temp over using a more rigid matrix material such as either a PVS bite registration material or even a rigid plastic "suck down" matrix

    Very often with a temp, a few extra SECONDS spent at the beginning of the visit to get a good matrix will end up saving you MINUTES towards the end of that same visit!
     
  14. omaralt

    omaralt Senior Member

    Joined:
    05.31.04
    Messages:
    687
    Status:
    Dentist
    SDN 10+ Year Member
    hire a dental assistant who knows how to make temporaries :) i've probably made one or two temps since i graudated :)
     
  15. Tenacious D

    Tenacious D Professional Lurker

    Joined:
    10.11.06
    Messages:
    10
    Location:
    Dayton, OH
    Status:
    Dentist
    SDN 2+ Year Member
    When I took on my associate position right out of dental school, the owner had me exclusively make temps for the first week and a half I was there. I didn't touch a clinical patient except to fabricate, adjust and cement provisionals. He felt that was single-handedly one of the most under-emphasized aspects of patient care taught in undergraduate crown and bridge courses. I now agree.

    In private practice, where chair time has a dollar value, to be constantly wasting 10-20 min. appts to see patients who aren't happy they have to be there is a financial, marketing, and public relations burden.

    Preparation dimensions and taper is key. That's always a given. Practice on a typodont if you need to but get good at reading margins and leave good proximal contacts alone. You'd be surprised how much retention you'll keep if there's a healthy proximal contact keeping that temp in place. As mentioned above, check and recheck your occlusion to minimize excursive contacts.
     
  16. mmasurf

    mmasurf

    Joined:
    12.05.06
    Messages:
    369
    SDN 7+ Year Member
    cotton isolation is key, u can get anything to stay on if the tooth/gingiva is dry . if you want to keep temps on longer just use durelon with a little swipe of vasaleine that will destablize the bonding and make this permanent cement weaker. im sure ppl say alginate is the best cause its cheap but why waste time, take a medium body quick quadrant or single tooth impression that will last you months, if the pt ever comes back and cause its more stable your more likely to get a better temp than a bulky alginate
     
  17. mmasurf

    mmasurf

    Joined:
    12.05.06
    Messages:
    369
    SDN 7+ Year Member
    lol wow 3 crowns thats like 1 or 2 a yr your better off not even telling that to anyone its just embarrassing.
     
  18. omaralt

    omaralt Senior Member

    Joined:
    05.31.04
    Messages:
    687
    Status:
    Dentist
    SDN 10+ Year Member
    also, i keep some temerex around in case a temp doesnt have good retention. it's a lot stronger then tempbond, and more likely than not your going to need to cut the temp off
     

// Share //

Style: SDN Universal