PFM noble fracture

[a3dl]

This case is only 2 months old delivered. Splinted unit with ERA attachment has fracture of porcelain. Looks like opaque layer and all separated from alloy. Heavy oxidation layer. This is PD55 alloy. This same incident happened on contralateral side(#11) two weeks ago. Any advice?

Not sure what we are doing wrong?
Is female too distal causing stress?
Splinted unit 6/7 too much stress?

 

[Polarmolar]

Check how you degas and wash opaque layer done is my first concern.


Sent from my iPhone using Tapatalk

 

[2000markpeters]

I do not think the attachment has anything to do with porcelain adhesion. It looks as if opaque has completely popped off. Was it applied in too thick of a layer possibly? Have you had this problem with this alloy before?

 

[rkm rdt]

heavy oxide?
remove oxide before opaque

 

[a3dl]

Have not had this problem..We have used this alloy for over 15 years. we use Ceramco 3 opaque paste and crystals

 

[a3dl]

heavy oxide?
remove oxide before opaque

We were dealing with lots of space to close.. Metal lingual prob should have been done to help support occlusal forces. Thanks

 

[PDC]

Have not had this problem..We have used this alloy for over 15 years. we use Ceramco 3 opaque paste and crystals

That right there is your problem my friend. I used that same stuff years ago and had the same issues. You can't get a visual cue of the opaque covered up with the crystals so you are totally reliant on the temps. The crystal technique might sound great but the bond is terrible. I remade a lot of units with that stuff.

 

[a3dl]

That right there is your problem my friend. I used that same stuff years ago and had the same issues. You can't get a visual cue of the opaque covered up with the crystals so you are totally reliant on the temps. The crystal technique might sound great but the bond is terrible. I remade a lot of units with that stuff.

If you dont mid letting me know what opaque and porc system you are using currently that would be amazing..may be looking to shift even though we do not do much pfm compared to yz anymore

 

[TheLabGuy]

We were dealing with lots of space to close.. Metal lingual prob should have been done to help support occlusal forces. Thanks

That was my first take on seeing the pictures.... I always do a metal lingual when doing these type attachment cases. I'd be interested in seeing lateral movements mounted up as well. Just to add, ERA attachment in my opinion isn't the best attachment to use in these type of cases. Much better options from Preat and Rhein83 when it comes to distal extension type of precision attachments than a ERA.

 

[ztech]

A free end saddle will exert enough force on the coping to flex it if it is not really thick. I would have done the metal lingual and kept the facial of the coping in the .7-.8 range. I am not a fan of the ceramco 3 and the crystals either. I helped a friend troubleshoot porosity problems and when we put the opaque under a high powered microscope, the opaque under the crystal was not bonded to the metal.

 

[a3dl]

Appreciate the feedback..hope this case doesnt keep biting us in rear. we did 6-11 and 20-28 along with cast partials

 

[PDC]

If you dont mid letting me know what opaque and porc system you are using currently that would be amazing..may be looking to shift even though we do not do much pfm compared to yz anymore

I use Vita VMK Master. Works with most any CTE. Mainly use it because of the 3D shades. Lot's of other good stuff out there like GC and Ivoclar. Anything but the Ceramco stuff with the crystals.

 

[PDC]

A free end saddle will exert enough force on the coping to flex it if it is not really thick. I would have done the metal lingual and kept the facial of the coping in the .7-.8 range. I am not a fan of the ceramco 3 and the crystals either. I helped a friend troubleshoot porosity problems and when we put the opaque under a high powered microscope, the opaque under the crystal was not bonded to the metal.

I think those crystals settle into the paste against the metal thus reducing any bonding ability (if any) of the paste itself. The crystals do not bond...they are there to improve light reflection and supposedly giving the crowns a more life-like appearance. The big selling point of this system was that almost anybody, including techs with little training, could do this technique.

 

[CatamountRob]