Milled denture base not seating

[dhdc]

Hi All, we have just started milling our dentures...we have the odd case where the base has a visible rock on the final models that were scanned.
I have tried in both a PM7 and S2 with same results.
It it normal to expect the denture not to fit back on the model, taking into account undercuts etc or should we expect them to click into place
Many thanks

 

[Rtyrelw]

Are they the same doctor every time? Are they digital scans? Or are they physical impressions?

 

[dhdc]

They are physical impression, scanned models

The bases just rock on the model

 

[TheLabGuy]

Milling base and teeth separate or ivotion?

 

[Rtyrelw]

What scanner are you using? When's the last time you calibrated it? That's interesting cuz I've had similar issues but only with doctors taking digital impressions. Never with a physical model. Does your 3D printed version have the same issue?

 

[dhdc]

Milling base and teeth separate or ivotion?

Separate teeth and base

 

[dhdc]

What scanner are you using? When's the last time you calibrated it? That's interesting cuz I've had similar issues but only with doctors taking digital impressions. Never with a physical model. Does your 3D printed version have the same issue?

3d printed try in is fine, calibration all in date???
I'm thinking it's just the undercuts or not blocking out enough in palate?

 

[Rtyrelw]

Possibly. Wonder if you can go back and look at these cases that this has been happening with. I'm interested to know what the problem is in case it comes up for me. Have you talked with ivaclar support or anyone like that?

 

[rlhhds]

Hi All, we have just started milling our dentures...we have the odd case where the base has a visible rock on the final models that were scanned.
I have tried in both a PM7 and S2 with same results.
It it normal to expect the denture not to fit back on the model, taking into account undercuts etc or should we expect them to click into place
Many thanks

The denture WILL NOT fit the base don't worry about it. When you process a denture does it fit the back on the model? No, you have to destroy the model to retrieve the denture because it has locked to the undercuts. Milled dentures are in effect modeless because of the process. Everything is worked out in the try in( bite, esthetics, fit) then milled and finished without fitting to a model. We have been milling dentures for over 3 years and this process works prefect in the hands of a competent doctor.

 

[jeppe]

Maybe you can try to take an impression when fitting denture on model so you can see where it does not fit? Should show where it's not fitting...

 

[rlhhds]

When this happens we have the Dr take a wash impression with the denture and that now becomes our new master. Unfortunately if this happens on the final we are having to mill a new final but that’s just how it goes sometimes.