advice wanted: interim crown practical problem

[coreyb]

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#21 crown prep and interim (temp crown) practical on Tuesday next week.

I'm not (overly) worried about the preparation, but my interim crowns suck!

I keep trimming down the interim to get the gingival overhang & straight emergence profile and end up opening the margins.

I then do the nealon technique to put more acrylic on, but end up doing the same thing again (open margins).

The faculty I've talked with haven't had much advice other than to take a lot of time when trimming with the moore's disk or the acrylic bur.

so: ANY GOOD ADVICE OUT THERE? 😕

 

[DrJeff]

#21 crown prep and interim (temp crown) practical on Tuesday next week.

I'm not (overly) worried about the preparation, but my interim crowns suck!

I keep trimming down the interim to get the gingival overhang & straight emergence profile and end up opening the margins.

I then do the nealon technique to put more acrylic on, but end up doing the same thing again (open margins).

The faculty I've talked with haven't had much advice other than to take a lot of time when trimming with the moore's disk or the acrylic bur.

so: ANY GOOD ADVICE OUT THERE? 😕

Do you "outline" the margins of your temp crown with a pencil prior to trimming?? If not, try this it works quite well for many folks. If a thin pencil mark is still on the temp after trimming, you know you haven't ground away the margin

 

[Elipar]

In my experience, difficulties with temporaries result from inadequate preparations. If you have an even thickness and clear, smooth margin, then it's pretty easy to trim the temporary. The advice from Jeff is excellent, and something most of us did when we first started making temps. You can also use loupes to see better.

 

[HuyetKiem]

Here is the trick in preclinic:
reline the acrylic interim with flowable (lightest shade as possible)
then use an explorer to remove the excess at the margin
light cure
polish.

down in the clinic, I use intergrity then reline with flowable. Lazy way to polish your temp: put a little bit of flowable on your finger then smear it on your temp then light cure. 😀😀

 

[armorshell]

Here is the trick in preclinic:
reline the acrylic interim with flowable (lightest shade as possible)
then use an explorer to remove the excess at the margin
light cure
polish.

down in the clinic, I use intergrity then reline with flowable. Lazy way to polish your temp: put a little bit of flowable on your finger then smear it on your temp then light cure. 😀😀

Got trowned for asking if we can do flowable relines in pre-clinic here. Always ask for forgiveness, not permission.

Think you could do the same thing with integrity and the original putty matrix? The only restriction given was we couldn't use materials not included in our kits.

 

[DrJeff]

Got trowned for asking if we can do flowable relines in pre-clinic here. Always ask for forgiveness, not permission.

Think you could do the same thing with integrity and the original putty matrix? The only restriction given was we couldn't use materials not included in our kits.

As someone who has used integrity for my temps almost exclusively for the last 7 or 8 years (I'll keep trying different companies brands, but I stick with the Integrity), if you're having to reline the temps to get the proper fit/margin, then you realy should look at the matrix you're using. With the great flowability of integrity as it's dispensed from the mixing tip, if your matrix is good, then your fit/margins will be there, and there should be no need to reline the temp.

 

[HuyetKiem]

With the great flowability of integrity as it's dispensed from the mixing tip, if your matrix is good, then your fit/margins will be there, and there should be no need to reline the temp.

Only if you fabricate the temp a night before with 0.5mm thickness 😀😀😀

 

[HuyetKiem]

Got trowned for asking if we can do flowable relines in pre-clinic here. Always ask for forgiveness, not permission.

Think you could do the same thing with integrity and the original putty matrix? The only restriction given was we couldn't use materials not included in our kits.

We're pretty open here at Case dental school. We are allowed to use any material in preclinic. Our instructors are only interested in our end results. Yup, I've tried different materials for temp and settled down with intergrity because of its esthetic, easy to manipulate and polishing, and quick.

In clinic, we have to ask permission from our preceptor and clinic director for any new material. Most of the time, they are pretty easy to be convinced if I have enough information and a good reason for the materials. My preceptor sometimes brings her own materials from her office for us to use in certain cases 👍👍 😍

 

[armorshell]

As someone who has used integrity for my temps almost exclusively for the last 7 or 8 years (I'll keep trying different companies brands, but I stick with the Integrity), if you're having to reline the temps to get the proper fit/margin, then you realy should look at the matrix you're using. With the great flowability of integrity as it's dispensed from the mixing tip, if your matrix is good, then your fit/margins will be there, and there should be no need to reline the temp.

Usually the biggest problems I have with integrity are the result of me having only a few months of experience with it. It always looks fantastic when I pop the putty matrix off, but I'm pretty consistent about opening up a margin somewhere or losing a contact.

In all likelihood I probably just haven't had enough practice, and am looking for a good way not to fail the provisional portion of my 20 FVC practical next week. 😳

 

[DrJeff]

Usually the biggest problems I have with integrity are the result of me having only a few months of experience with it. It always looks fantastic when I pop the putty matrix off, but I'm pretty consistent about opening up a margin somewhere or losing a contact.

In all likelihood I probably just haven't had enough practice, and am looking for a good way not to fail the provisional portion of my 20 FVC practical next week. 😳

For the contact problem, grab the pencil again, mark the contact BEFORE you start trimming, if you still have a pencil mark when you're done trimming, you still have a contact👍

For the margins, really make sure you have a visualization of what the margin looks like on the tooth before you trim, that plus the pencil mark trick should help alot. Personally, I make my finish line with either a REALLY deep chamfer or a 90 degree butt joint depending on the type of material the crown will be made out of. This way it's really clear cut where the margin of the temp crown ends and where the flash begins👍

 

[armorshell]

For the contact problem, grab the pencil again, mark the contact BEFORE you start trimming, if you still have a pencil mark when you're done trimming, you still have a contact👍

For the margins, really make sure you have a visualization of what the margin looks like on the tooth before you trim, that plus the pencil mark trick should help alot. Personally, I make my finish line with either a REALLY deep chamfer or a 90 degree butt joint depending on the type of material the crown will be made out of. This way it's really clear cut where the margin of the temp crown ends and where the flash begins👍

The contact tip is really helpful, that's definitely a useful tidbit. I'll give the pencil trick a shot too, the margins our pre-clin professors want are pretty conservative for this preparation though, and there's not a lot of wiggle room to make them nice and evident.

 

[1992Corolla]

man I am still using jet acrylic...so archaic!

 

[Elipar]

For the contact problem, grab the pencil again, mark the contact BEFORE you start trimming, if you still have a pencil mark when you're done trimming, you still have a contact👍

For the margins, really make sure you have a visualization of what the margin looks like on the tooth before you trim, that plus the pencil mark trick should help alot. Personally, I make my finish line with either a REALLY deep chamfer or a 90 degree butt joint depending on the type of material the crown will be made out of. This way it's really clear cut where the margin of the temp crown ends and where the flash begins👍

I'm with you, Jeff. Clear margins = well-fitting temporary, and more importantly, well-fabricated crown. But Armorshell is right. In pre-clinic, the margins are conservative as hell. Yet, if you look at the work of those who are grading you'll see much more aggressive margins.

 

[armorshell]

I also forgot to mention something, which I'm not positive is true in all the other pre-clin labs across the country, but our typodonts have some significant "black triangles" that I understand are normally filled in a living patient. This gives us a ton of extra temporary material to trim away from the proximal margins.

Now that I think about it, were it not for the ridiculous amount of trimming we have to do proximally I don't think this would be a problem. My buccal and lingual margins always rock right out of the putty.

 

[djeffreyt]

Armor if you didn't spend all day online looking for answers...you could get more practice in before our practical next week.

I use a pretty simple trick which has worked well for me. Not sure if I would do it in a patient mouth yet.

Make a putty matrix, do the prep, use integrity in the putty to make the temp.

To trim the temp, I just use brassler trimmers almost to the margin. I leave 0.1 or 0.2 mm of space at the margins and use the pencil trick on the contacts to avoid trimming that away. I polish using polishing burs, but don't polish the margin with them. I use the rainbow kits and using the flossing polishing strips to polish the margins while the margins are in the typodont. This gives a great, unopened, fit from the temp to the margins of the prep. I've only used it on margins that are supragingival, so I don't know how it would work with patients with subgingival prep margins.

 

[tinker bell]

I pull articulating paper thru proximal, and it marks the contacts for me. Then I know where I should not touch. I remember I was allowed to use integrity since second year and I've been using it since. But it's good to know how to use acrylic though

 

[armorshell]

As if there's not a time when I'm not in the lab when I possibly can be. Maybe if we weren't required by law to sit through pointless anatomy lectures I'm going to have to teach myself anyway I could be prepping more teeth. Besides, at the time there was a big pile of 2nd years occupying our half of the sim lab.

Good nugget on the interproximal strips against the margins, I'm going to try sneaking some light body aquasil around the margins of my putty as well, we'll see how that goes tomorrow.

 

[HuyetKiem]

You are not allowed to reline your temp ? If you can't use flowable, then

. squeeze a bit of intergrity of a mixing pad (don't use mixing tip)
. mix a little bit at a time then add it on the temp's margin with composite instruments
. place the temp back on your prep
. remove an excess at the margin with the explorer
. polish

if you have an open contact after trimming, add a little bit of hand mixing intergrity in that area to reestablish the contact.

It was kidda pain trying to make a perfect temp with 1.5mm shoulder and 0.25mm bevel finish line or 0.5mm FGC feather edge. Great memories from preclinic lab. 😀

 

[DrJeff]

man I am still using jet acrylic...so archaic!

Jet acrylic, Mmmmmm the smell of free monomer!👍😉😀

 

[tinker bell]

I used to put acrylic temp in hot water until it's completely set before I took it out of the prep & trim it. That is one way to avoid shrinking & open margin.
1. Put the whole typodont into a bowl of hot water, wait for at least 3 minutes.
2. Trim
3. Polish with soflex discs.

 

[DrJeff]

I used to put acrylic temp in hot water until it's completely set before I took it out of the prep & trim it. That is one way to avoid shrinking & open margin.
1. Put the whole typodont into a bowl of hot water, wait for at least 3 minutes.
2. Trim
3. Polish with soflex discs.

Better be sure that there aren't any undercuts in that prep then! Always fun when you get to cut a locked on temp off a tooth😱😀

 

[coreyb]

Unfortunately I'm stuck with using "Duralay" acrylic (hand mix powder polymer and liquid monomer in dappendish). The stuff seems like garbage to me, but I don't have much experience with other brands/types.

I will make sure to mark with pencil on margin and contacts.

Thanks for all the advice so far!
🙂

 

[armorshell]

Used the pencil marking techniques today on the margin and contacts, my stuff is looking much better. Thanks guys!

 

[DrJeff]

Used the pencil marking techniques today on the margin and contacts, my stuff is looking much better. Thanks guys!

Glad it helped! It's one of those little tricks that is so simple, yet can make a very big difference👍

 

[armorshell]

Oh yeah, I also took your advice and did a decent prep this time too

 

[tinker bell]

Look at shillinburg, the smaller book with lots of color pictures, he has step by step that instructs how to prep crown very efficient. It makes your life easy if you follow those steps, and know how your prep supposed to be. Always start with the finish picture.
Hmm, final is fast coming.

 

[armorshell]

Turns out I was just in the eye of the storm. I went back to sucking again

 

[djeffreyt]

Turns out I was just in the eye of the storm. I went back to sucking again

Everyone sucked it up tonight in lab. With only 15 minutes left before closing and while finishing the polishing on my temporary with the brassler it shot out of my hand and across the room to who knows where.

Guess I'm going in early tomorrow to see if I can crank out another one before class starts.