How to do refractory models?

[H.Ross]

Hello guys, I always do refractory models in two different ways. But I wanted to learn or adjust my method with your help. What do you suggest?

1- Pour the impression with stone, ditch the margins, duplicate it with silicone, then pour it with refractory. This method is fast and good for a maximum two unit veneers with minimal prep.

2- Pour the impression (only prep) and increase the height of stone,
separate the stumps,
ditch the margins,
create anti rotation grooves,
duplicate stumps with silicone,
pour the silicone with refractory,
put the refractory stumps back in impression,
brush them with separator,
pour impression with stumps attached using stone,
Final model in picture

This picture taken from Miladinov Milos page on Facebook

 

[Car 54]

Thanks for posting this, Ross, I was wondering how you did yours. I thought it would be along this line of steps, it seems to be the default way of doing refractory these days. Do you in your above steps, paint die spacer on the preps before you duplicate them or is there something on the preps in the picture acting as die spacer?

Back before the technique you showed became popular, I used to pour distal to the prep units the contacts and back, out of die stone to create a dam. After that hardened, I would pour the prep part of the impression with refractory. Then carefully separate it from the impression and trim it. This is where it got expensive, was to drill holes in the bottom with a pinning machine which would toast the drill bits after about 2-3 drills (I later tried round burs),notch the labial and lingual of each die, use reversible dowel pins, put separator on it and base it. I then used a thin disc to separate the units and degass them in a burn out oven. Did a coat or two of refractory die spacer and went from there.

This worked good for a couple of units, but wasn't as secure as your technique, as the dies would tend to wobble after multiple firings.

Also, I learned that either pouring up the stone first, distal to the preps, the refractory wouldn't stick to the dies stone..or I had to put rope wax distal to the preps to make a dam, pour the refractory part first, then the die stone part distal to the refractory so it would stick (bond) to the refractory material, it was one way or the other, I forget.

 

[JMN]

What I did was pour in diestone, drill, then pin. normal bi-pins on parts not needing to be refractory, ceramic pins where they needed to be refractory. The ceramic pins are teardrop shaped and taper as they go apically 'down'.

With a straight burr cut positioning anti-rotation dents pn the underside as divots or half-moon grooves on apical/facial under-corner and again on lingual/palatal/back.

Vaseline very lightly, (dont even dip your brush again if ypu have a small brush set aside for that) on the ceramic pins (micro-texture issues sometimes) and use supersep or whatever stone separator agent you like.

Pour base, saw normally and tri, dies. Paint 3 layers of 0 agstrom Euro Die Sealer on the dies to be refractory.

The fun part: Cut a plastic graduated cylinder like comes with most investment for liquid measurement abput 2-3 mm taller than the dies are above the base. Remove everything frpm the base and coat it in vaseline, not heavy at all, just no bare stone.
Place to-be-refractory dies on base. Grab a bit of light cure baseplate material and put it arpund the bottom of the chopped graduated cylinder, press it to tje base and lightcure.
Now you've a solid, repeatably placeable matrix holder. Put a sprue of wax towards the back/center of the base connecting the die(s) and the cylinder wall. Outline the wax with a sharpie.
Pour your favorite silicone dup material into the top of the cylinder and go to lunch

After silicone sets, remove the die/cylinder/silicone set from the base. Cut a hole where the wax sprue is outlined and rempve the wax before the die. Wax just pulls out with a discoid.
Remove die and wait a bit for silicoe to return to rest shape. Take a labknife burr or whatever and complete yhe hole from the ceramic pins to the bottom of the base f0r dust evacuation with air pressure.
Apply debublizer 0f chioce tp inside of silicone.
verify vaseline layer and reapply if needed under die/silicone area. Put new ceramic pins in their holes after putting the tiny vaseline layer on the shaft only-not the head.
Pour refractory material into silicone until it nears spruehole. Attach to the base and finish pouring through spruehole.

After refractory sets, rem0ve the material of the cylinder and lighycure beneath the spruehole.
Refractory die slides out and break/grind off the sprue.

Whew!

 

[JMN]

Hello guys, I always do refractory models in two different ways. But I wanted to learn or adjust my method with your help. What do you suggest?

1- Pour the impression with stone, ditch the margins, duplicate it with silicone, then pour it with refractory. This method is fast and good for a maximum two unit veneers with minimal prep.

2- Pour the impression (only prep) and increase the height of stone,
separate the stumps,
ditch the margins,
create anti rotation grooves,
duplicate stumps with silicone,
pour the silicone with refractory,
put the refractory stumps back in impression,
brush them with separator,
pour impression with stumps attached using stone,
Final model in picture

This picture taken from Miladinov Milos page on Facebook

View attachment 20863

Your way certainly looks easier! I'd worry about the prep holding still in the impression while vibrating and supporting all the cantilevered shaft weight. How d0 you get it to stay put?

 

[Car 54]

I remember some people were putting a little wax on the labial/lingual to help stabilize the dies while pouring.

I forgot about the ceramic pins, I tried those, too. I still have about 8 left from B & D dental (Durafractory zirconia pins). I would set the pins while the refractory was setting up, then later would make some grooves with a #6 or 8 bur, to help with seating orientation.

edit:sp

 

[Car 54]

H.Ross, I know you've probably mentioned in one of your other posts, but what porcelain are you using for your refractory restorations?

Is it a good idea to use a high fusing system like CC, so you can use a lower temp porcelain for add ons if needed, once the units are devested? I know with these type of cases, but especially with the 6 unit veneer cases, we're probably working from a diagnostic wax up, or "approved" provisional cast from what has been worked out and confirmed in the mouth. It's just that sometimes something needs to be added on to, what do you use or do for that?

Thanks

 

[JKraver]

Refractory material is mixed with tears not water huge pain.

 

[JMN]

Refractory material is mixed with tears not water huge pain.

That and soylent green

 

[H.Ross]

Thanks for posting this, Ross, I was wondering how you did yours. I thought it would be along this line of steps, it seems to be the default way of doing refractory these days. Do you in your above steps, paint die spacer on the preps before you duplicate them or is there something on the preps in the picture acting as die spacer?

Back before the technique you showed became popular, I used to pour distal to the prep units the contacts and back, out of die stone to create a dam. After that hardened, I would pour the prep part of the impression with refractory. Then carefully separate it from the impression and trim it. This is where it got expensive, was to drill holes in the bottom with a pinning machine which would toast the drill bits after about 2-3 drills (I later tried round burs),notch the labial and lingual of each die, use reversible dowel pins, put separator on it and base it. I then used a thin disc to separate the units and degass them in a burn out oven. Did a coat or two of refractory die spacer and went from there.

This worked good for a couple of units, but wasn't as secure as your technique, as the dies would tend to wobble after multiple firings.

Also, I learned that either pouring up the stone first, distal to the preps, the refractory wouldn't stick to the dies stone..or I had to put rope wax distal to the preps to make a dam, pour the refractory part first, then the die stone part distal to the refractory so it would stick (bond) to the refractory material, it was one way or the other, I forget.

Good points I got from you, thanks for sharing your experience. Yes, I do use spacer on the stone dies. However, I tried once pouring the refractory directly in impression, but I had small chips on refractory material stuck in some corners so I didn't have the guts to continue the work. I use silicone because its extremely flexible and soft, I use Zhermack.

I loved the idea of creating a dam, actually you can also create a dam by adding putty on distals. and btw this is not my picture, as I said taken from Miladinov Milos Facebook page.

What I did was pour in diestone, drill, then pin. normal bi-pins on parts not needing to be refractory, ceramic pins where they needed to be refractory. The ceramic pins are teardrop shaped and taper as they go apically 'down'.

With a straight burr cut positioning anti-rotation dents pn the underside as divots or half-moon grooves on apical/facial under-corner and again on lingual/palatal/back.

Vaseline very lightly, (dont even dip your brush again if ypu have a small brush set aside for that) on the ceramic pins (micro-texture issues sometimes) and use supersep or whatever stone separator agent you like.

Pour base, saw normally and tri, dies. Paint 3 layers of 0 agstrom Euro Die Sealer on the dies to be refractory.

The fun part: Cut a plastic graduated cylinder like comes with most investment for liquid measurement abput 2-3 mm taller than the dies are above the base. Remove everything frpm the base and coat it in vaseline, not heavy at all, just no bare stone.
Place to-be-refractory dies on base. Grab a bit of light cure baseplate material and put it arpund the bottom of the chopped graduated cylinder, press it to tje base and lightcure.
Now you've a solid, repeatably placeable matrix holder. Put a sprue of wax towards the back/center of the base connecting the die(s) and the cylinder wall. Outline the wax with a sharpie.
Pour your favorite silicone dup material into the top of the cylinder and go to lunch

After silicone sets, remove the die/cylinder/silicone set from the base. Cut a hole where the wax sprue is outlined and rempve the wax before the die. Wax just pulls out with a discoid.
Remove die and wait a bit for silicoe to return to rest shape. Take a labknife burr or whatever and complete yhe hole from the ceramic pins to the bottom of the base f0r dust evacuation with air pressure.
Apply debublizer 0f chioce tp inside of silicone.
verify vaseline layer and reapply if needed under die/silicone area. Put new ceramic pins in their holes after putting the tiny vaseline layer on the shaft only-not the head.
Pour refractory material into silicone until it nears spruehole. Attach to the base and finish pouring through spruehole.

After refractory sets, rem0ve the material of the cylinder and lighycure beneath the spruehole.
Refractory die slides out and break/grind off the sprue.

Whew!

haha Whew! I never tried your technique, but I am curious to try it!

Your way certainly looks easier! I'd worry about the prep holding still in the impression while vibrating and supporting all the cantilevered shaft weight. How d0 you get it to stay put?

I remember some people were putting a little wax on the labial/lingual to help stabilize the dies while pouring.

I forgot about the ceramic pins, I tried those, too. I still have about 8 left from B & D dental (Durafractory zirconia pins). I would set the pins while the refractory was setting up, then later would make some grooves with a #6 or 8 bur, to help with seating orientation.

edit:sp

Yes, I would put wax, but I pour first the prep area following the stone proper mix, but for adjacent teeth I make my stone slightly more flowable, so vibrator isn't on max.

H.Ross, I know you've probably mentioned in one of your other posts, but what porcelain are you using for your refractory restorations?

Is it a good idea to use a high fusing system like CC, so you can use a lower temp porcelain for add ons if needed, once the units are devested? I know with these type of cases, but especially with the 6 unit veneer cases, we're probably working from a diagnostic wax up, or "approved" provisional cast from what has been worked out and confirmed in the mouth. It's just that sometimes something needs to be added on to, what do you use or do for that?

Thanks

Yes, I use recently creation CC, awesome results, and I've also used Vita VM9 before, but happier with CC now.

That is why I love high temp porcelain, so I can adjust them on lower temp if any MINOR correction needed. Well, regarding your question of what to do incase it wasn't right in patient mouth? answer is plenty of F words lol

 

[Car 54]

Good points I got from you, thanks for sharing your experience. Yes, I do use spacer on the stone dies. However, I tried once pouring the refractory directly in impression, but I had small chips on refractory material stuck in some corners so I didn't have the guts to continue the work. I use silicone because its extremely flexible and soft, I use Zhermack.

You're right, I did experience that once in awhile. Fortunately, most of my accounts at that time were using a polyvinyl. It would have probably been a nightmare if they were using a polyether.

Thanks for answering my (our) questions, I also appreciate the the tip on Zhermack. You're getting me curious to want to try refractory again.

 

[H.Ross]

You're right, I did experience that once in awhile. Fortunately, most of my accounts at that time were using a polyvinyl. It would have probably been a nightmare if they were using a polyether.

Thanks for answering my (our) questions, I also appreciate the the tip on Zhermack. You're getting me curious to want to try refractory again.

No worries, I am more than happy. Refractory is nice, preparing the models and refractory dies will smoothen all the steps and make results more predictable.

I also learned something, I promote it for dentists who deserve it only. I don't sell it as piece of work.

 

[Car 54]

Good point, present it to dentists who would appreciate it, and would pay for the effort and the results.

 

[H.Ross]

http://www.dynamicabutment.com/novox/

Check Novox, alternative for stone. Useful for making stumps prior to duplicating them with silicone, then pouring adjacents with stone without having to worry about stone sticking to it, does not need vaseline or separator.

 

[JMN]

Good points I got from you, thanks for sharing your experience. Yes, I do use spacer on the stone dies. However, I tried once pouring the refractory directly in impression, but I had small chips on refractory material stuck in some corners so I didn't have the guts to continue the work. I use silicone because its extremely flexible and soft, I use Zhermack.

I loved the idea of creating a dam, actually you can also create a dam by adding putty on distals. and btw this is not my picture, as I said taken from Miladinov Milos Facebook page.



haha Whew! I never tried your technique, but I am curious to try it!






Yes, I would put wax, but I pour first the prep area following the stone proper mix, but for adjacent teeth I make my stone slightly more flowable, so vibrator isn't on max.



Yes, I use recently creation CC, awesome results, and I've also used Vita VM9 before, but happier with CC now.

That is why I love high temp porcelain, so I can adjust them on lower temp if any MINOR correction needed. Well, regarding your question of what to do incase it wasn't right in patient mouth? answer is plenty of F words lol

That's what we were using on ours too. Our ceramist was a-maz-ing with the Creation line. And actually was tapped as a trainer when it first came out. Here in the sticks we had docs call upset about the cracks in their porc work, they just didn't get that was not a crack but excellent mimicry. Sad.

 

[Car 54]

http://www.dynamicabutment.com/novox/

Check Novox, alternative for stone. Useful for making stumps prior to duplicating them with silicone, then pouring adjacents with stone without having to worry about stone sticking to it, does not need vaseline or separator.

It would also be great for pouring up dies for emax press, to help keep the integrity of the margins.

 

[JMN]

The silicone we used was Sterngold's 20min set. Tried the 10min set. It was more rigid, brittle, and tore easily in comparison.

 

[H.Ross]

That's what we were using on ours too. Our ceramist was a-maz-ing with the Creation line. And actually was tapped as a trainer when it first came out. Here in the sticks we had docs call upset about the cracks in their porc work, they just didn't get that was not a crack but excellent mimicry. Sad.

If cracks are being made during ceramic phase to mimic the adjacent tooth then this is awesome and acquire good skills to do cracks!

BUT, if cracks appeared after cementation then one of the major reasons that dentist used wrong cement. Cements with high expansion will cause cracks, luckily the veneer won't chip off but the crack will be visible in patient mouth.

 

[Car 54]

That's what we were using on ours too. Our ceramist was a-maz-ing with the Creation line. And actually was tapped as a trainer when it first came out. Here in the sticks we had docs call upset about the cracks in their porc work, they just didn't get that was not a crack but excellent mimicry. Sad.

A friend I shared space with was one of the first on-board when CC hit the states. Dr Winter helped to get it here, and used to be the one my friend would call to get tech support.

I believe Creation (Klema) had to re-formulate Creation for the metals we were using here, as compared to Europe, to help alleviate the cracking due to cte problems (aside from your friends ability to create natural ones). That was when Creation unfortunately got the moniker of crackation, but that changed with the cte change and is now an excellent brand, no matter what line of Creation a person would have and use.

 

[JMN]

If cracks are being made during ceramic phase to mimic the adjacent tooth then this is awesome and acquire good skills to do cracks!

BUT, if cracks appeared after cementation then one of the major reasons that dentist used wrong cement. Cements with high expansion will cause cracks, luckily the veneer won't chip off but the crack will be visible in patient mouth.

These were preseating mimics. She was truly gifted.

 

[Car 54]

If cracks are being made during ceramic phase to mimic the adjacent tooth then this is awesome and acquire good skills to do cracks!

BUT, if cracks appeared after cementation then one of the major reasons that dentist used wrong cement. Cements with high expansion will cause cracks, luckily the veneer won't chip off but the crack will be visible in patient mouth.

This brings back another memory. The last refractory case I did, were 2 laterals out of Shofu Halo...beautiful for refractory, but they both cracked after seating. One at chair side, and the other a couple of days later. I think your post reminded me of that, or I had forgotten about the wrong cement the Dr had used.

Also, refractory should only be bonded to enamel, and not on any composite build ups, i.e it needs to be a pretty clean and specific type of prep for a refractory veneer to be used. Some dentist don't get that, and would want to use those on improper tooth structure and have failures.

So the things you're reminding me of, are kind of the things that drove me away from refractory, as emax for the general dentist, is more forgiving.