We have been using our Cerec w Ivoclar e.Max for about 6 years now and have noticed a significant difference in the debonding of our milled crowns vs the pressed lab restoration we receive from outside labs
We have used multilink and now Panavia and adhere strictly to the isolation and cementation protocols from the manufacturer
The cement is always on the tooth and never any on the intaglio of the restoration whether it be crown or veneer
We use a steamer to ensure clean restoration and have tried to use soap as it was implied at some time that the lubricant in the mill could be effecting bond?

Has anyone else noticed this? What do you do when a crown debonds?

We have had Ivoclar recommend running the restoration up on correction setting in the oven and starting cementation process from step 1

Also been advised to not re etch and just start with Ivoclean and bond from that step

There have been indications that over or under etching can be the culprit and albeit the etch pattern on our cerec milled crowns is never as intense as the lab etched pressed crowns but again we adhere to the time recommended but he HF etch manufacturer Ivoclar

Please advise or share your experience
Margaret, CDA on behalf of Dr Dennis Lichorwic