Puzzling Occlusal Issues

[cckowali]

Hello all, we have been having some very odd occlusal issues recently that have me flummoxed. We keep running into high occlusions that only exist in the patients mouth. Everything looks good on our models and designs but when the Dr. goes to insert he is sometimes grinding almost a mm away. The issue has occurred with both FCZ and PFM restorations and only occurs sporadically and only with some Drs. Due to it's occurrence in different materials and it's only occasional nature isolating the reason has become very difficult. This issues are only present on traditional impressions and not scanned cases.

Have any of you run into an issue like this before and if so how were you able to correct it? We have double checked all our settings for our stone mix, recalibrated our mill and sintering furnace, checked to make sure that all shrinkage rates for zirconia were entered correctly and just about anything else that has crossed our minds to try to troubleshoot the issue. If anyone has any ideas that could save me from putting my head through a wall they would be greatly appreciated.

 

[MasterCeramist]

The impressions you are receiving likely have some distortion.

 

[CoolHandLuke]

sounds like someone needs to relearn how to take 2stage impressions.

 

[mmbh]

Coolhandluke ditto. Also, check to see if they are using a triple tray impression technique / two stage technique. Can cause Hydrostatic pressure, causing a rebound effect.

 

[cckowali]

Thank you very much for your feedback, that is what we were thinking as well. Now for the joy of telling the docs the issues most likely are on their end.

 

[sidesh0wb0b]

Thank you very much for your feedback, that is what we were thinking as well. Now for the joy of telling the docs the issues most likely are on their end.

couple things, can you post a pic of the impressions?
my guess is its a failed H&H technique

or, someone is making temps WAY out of occlusion and the tooth is erupting into the vacated space.

my vote is option 1, there is something wrong with the impression. any chance you run into crowns that seem to not fit for this same client? crowns way too small for the prep, that sort of issue.

 

[Andrew Priddy]

ask them to take 2 triple trays for a while.. pour/compare/verify

 

[bigj1972]

Hello all, we have been having some very odd occlusal issues recently that have me flummoxed. We keep running into high occlusions that only exist in the patients mouth. Everything looks good on our models and designs but when the Dr. goes to insert he is sometimes grinding almost a mm away. The issue has occurred with both FCZ and PFM restorations and only occurs sporadically and only with some Drs. Due to it's occurrence in different materials and it's only occasional nature isolating the reason has become very difficult. This issues are only present on traditional impressions and not scanned cases.

Have any of you run into an issue like this before and if so how were you able to correct it? We have double checked all our settings for our stone mix, recalibrated our mill and sintering furnace, checked to make sure that all shrinkage rates for zirconia were entered correctly and just about anything else that has crossed our minds to try to troubleshoot the issue. If anyone has any ideas that could save me from putting my head through a wall they would be greatly appreciated.

If just one account,, their issue. If multiple, look inward. Those not affected, check to make sure they're not just being quiet..

If your milling in house, design a tester to check. If equipment checks out, back on them.

Also inspect impressions and reject when necessary. They're gonna get aggravated either way, better to be canceled for being picky than being
"a bad lab". If they are the problem, trouble will follow them.

My guess is assistant dentistry and the old Dr impression check from 2 chairs down.

 

[rkm rdt]

What about adjacent contacts and margins? Are they accurate?

 

[cckowali]

I'm trying to upload pictures of the impression from the latest case and am having trouble doing that.

What about adjacent contacts and margins? Are they accurate?

Adjacent contacts and margins are spot on to their preferences. The only are we are having the issues is on the occlusions. We had an issue with one other dentist and it turned out that the materials he was using on his end were incompatible and once he took care of that the issues stopped.

 

[Andrew Priddy]

is the Dr getting the crown fully seated?

 

[JKraver]

is the Dr getting the crown fully seated?

1mm would be a heck of a visible margin gap is the prep sub-g?

 

[JKraver]

Its likely an assistant making a temp out of occlusion or the temp coming off then being ground into occlusion when they recement. Or bad impression technique do you have an lab scanner? Basically the more you seem to do on your end to figure out their problem the better they will think of you. Just approach it as I am checking the problems on my end here are the things that you could check on your end. Leave it at that, might help for a little bit. You could make prep occlusal distance check out of some hard material. To show that the space on the model given with their bite was where their crown was set to. Sometimes patients just don't bite right they are numb and they take the bite and shade after the 30 minute bite blocked prep. Do you check lateral and protrusive interferences. Sometimes that makes all the difference.

 

[FASTFNGR]

Hello all, we have been having some very odd occlusal issues recently that have me flummoxed. We keep running into high occlusions that only exist in the patients mouth. Everything looks good on our models and designs but when the Dr. goes to insert he is sometimes grinding almost a mm away. The issue has occurred with both FCZ and PFM restorations and only occurs sporadically and only with some Drs. Due to it's occurrence in different materials and it's only occasional nature isolating the reason has become very difficult. This issues are only present on traditional impressions and not scanned cases.

Have any of you run into an issue like this before and if so how were you able to correct it? We have double checked all our settings for our stone mix, recalibrated our mill and sintering furnace, checked to make sure that all shrinkage rates for zirconia were entered correctly and just about anything else that has crossed our minds to try to troubleshoot the issue. If anyone has any ideas that could save me from putting my head through a wall they would be greatly appreciated.

Check the contact paper or articulating paper that they are using because I have seen some assistants using a denture articulating paper to adjust the temp crown and even take them out of occlusion. When they do that and by the time you finish the crown in 2 weeks the tooth supper erupt in the patient’s mouth. Both have to be using the same articulating paper thickness.

 

[JKraver]

Check the contact paper or articulating paper that they are using because I have seen some assistants using a denture articulating paper to adjust the temp crown and even take them out of occlusion. When they do that and by the time you finish the crown in 2 weeks the tooth supper erupt in the patient’s mouth. Both have to be using the same articulating paper thickness.

Most Drs prefer that the lab uses thicker paper than he does lol.