Anybody tried to remove a screw retained crown from titanium abutment after cementation?

[ZionDental]

Has anybody tried to remove a screw retained crown from titanium abutment after cementation? Our lab usually do E-max press on titanium temporary abutment and cement them which becomes screw retained Emax crown. The only Con about this is that whenever the drs needs to add a contact we cant really fire them in the oven together so i was wondering if anybody else faced this problem as well and knows any solution. I have heard that there was a way that u can slowly raise oven temp and separate the crown from the temp abutment but didnt really worked on me when i tried it. Any advice will be appreciate!

 

[JMN]

Dunno abouy emax, but we'd put pfms in the burnout at 725c f0r 45min. Then,pulling on both sides with a rubber dam. If no luck, we'd try again but this time put an icecube on the interface, shrinks the interface and abutment faster then the air cooling crown.

But again, I have no idea how this will affect Lithium Disilicate's color or physical properties.

Oh, the burnout was hot on entry, no runup.

Did you ask the cement maker what process they have, or what it's breakdown temp is?

 

[Gru]

read: http://dentallabnetwork.com/forums/...d-titanium-zirconia-abutment.9650/#post-56584

post #11 and on. It might help

Also: http://dentallabnetwork.com/forums/threads/crown-removal.10845/#post-69204

post #4.

 

[adl]

read: http://dentallabnetwork.com/forums/...d-titanium-zirconia-abutment.9650/#post-56584

post #11 and on. It might help

Also: http://dentallabnetwork.com/forums/threads/crown-removal.10845/#post-69204

post #4.

Gru knows!

 

[Gru]

sad but true.

edit: I don't offer them anymore. Bob (below) is right.

 

[BobCDT]

Based on our experience, the e.max breaks or cracks if you try to burn out the cement. I believe the difference in CTE is too great. We have moved away from screw retained e.max for his specific reason.
Replacing e.max with zirconia and using Multilink is a better solution as one can easily burn out the resin, do an add on and rebond the parts.

 

[rkm rdt]

As Bob said, zirconia is a better option. In fact ,the whole point of a screw retained crown is it's retrievability .
If the crown cannot be simply modified through addition or reglazing, then there is no point in it being screw retained.

 

[ZionDental]

Thanks guys it truely helped. Well the point we used Emax screw retained was that that monolithic strength of emax was better than strength of zirconia over porcelain. And I know for full strength its better to do full zirconia but i still believe full zirconia just dont fully satisfy me with esthetic issue. But your answers truely helped! really appreciate it!

 

[BobCDT]

What was the tooth number for this unit? If it was an anterior, you can always do a buccal cut beck and layer. This is very predictable and if designed correctly there is zero load on the layered ceramic. And you could now separate the bonded parts.

 

[rkm rdt]

Thanks guys it truely helped. Well the point we used Emax screw retained was that that monolithic strength of emax was better than strength of zirconia over porcelain. And I know for full strength its better to do full zirconia but i still believe full zirconia just dont fully satisfy me with esthetic issue. But your answers truely helped! really appreciate it!

I'm not so sure that emax is stronger since it is not bonded but cemented over an abutment. Sure Emax is strong when bonded to enamel but if your cutback pfz is breaking or chipping then you're not doing it correctly.

I'm not saying you in particular, but some people think the zirconia has to be the same design as a metal coping.They can't seem to wrap their heads around strategic cutbacks or " minimal layering".

In terms of esthetics, I can make either look great but prefer zirconia. In fact I am not that interested in the new translucent zirconias.

 

[ZionDental]

Most of the crowns were posterior crowns and definitely cutback technique need to get applied different style for different restoration. Anyway Zirconia has more advantage on shade control with minimal spaces unlike pfms. Some prefer emax cutback and layer and some prefers zirconia cutback with layering~

 

[MetalMachine]

I have done it a couple of times but emax usually breaks. Pretty low heat, long time and it might stay whole. But I can't quarantee it is as durable as it was before firing..

 

[[email protected]]

I have done a number of these emax over Ti abutments, have not needed to add contacts as i use an unsectioned model for the crown. You have to make sure contacts are sweet before you bond the crown, havent had any comebacks for contacts yet.
If i do anteriors i tell the docs to make an appt for a try in, there is a temp try in luting material (made by Ivoclar)i do this so that they can check shade etc and i can still make changes if needed, if no changes needed they send it back and I do the final bonding.
Its an extra appointment for the patient but at least we get it right, saves problem of having to separate crown from abutments after the fact.
For what its worth thats how I avoid the OP problem.

 

[grantoz]

i would get the lab that did the crown for you you may need to pay a fee for the correction if you have taken a bad impression.JKraver im waiting.