Are you over etching e.max? A tip...
Are you over etching your e.max? Even though e.max is stronger than conventional porcelain, it is treated much differently. When using a 5% HF etch, you only etch the intaglio of the restoration for 20 seconds. If you over etch emax, you will notice a frosted appearance on the inside of the restoration. If this occurs, the rods that you are bonding to are weakened and you need to remove them. How do we do this? I was talking with Don Bell from Ivoclar and he gave me the answer. Don Bell says that you need to put that over etched restoration in a zip lock baggie with alcohol and place it in an ultrasonic for 5 minutes. This will remove the over etched rods and allow you to re-etch for the appropriate time.....20 seconds. Thanks for the info Don.
Rich,
I appreciate your sharing. However, I think this issue needs a little more clarification. I etch my Emax restorations for 20 seconds by the clock. At worst, if we are slow to start rinsing, they get, at most, maybe 5 seconds more etching time. They always have a somewhat frosty appearance on the intaglio compared to the external surface, even before being etched. We are etching, after all. So my question is, according to Don Bell, how frosty is too frosty?
Dr. Chuck, the pics that I have seen are very frosted. next time you are in Scottsdale, mill out 2 restorations and etch one for 20 and 1 for 60 and I think you'll see a marked difference. I use interface a lot so I don't see that, but most people I know use HF etch and silane and I wanted to put this out there. A lot of people tend to not realize that emax is only etched 20 seconds and that was the main point of the blog here. I'll see Don Bell tomorrow and find out what Don Bell Says.
what about 9.6% HF acid? our office has only 9.6% HF not 5% HF. is it still ok to etch for 20 sec for emax crown?
On 8/21/2015 at 12:42 pm, Grace Lee said...what about 9.6% HF acid? our office has only 9.6% HF not 5% HF. is it still ok to etch for 20 sec for emax crown?
no grace, you should cut it down to 10-12 seconds. better yet would be getting etch and prime from Ivoclar and get rid of HF etch and silane all together!!
How come information like this pops up after years of using glass ceramics? I never knew effect of longer etching and i dont remember anyone pointing out the importance.
Same with Enamic...thank God i got that info on time.
Danny, this thread is 2 years old so it didn't quite just pop up. I remember doing this blog right after Don Bell gave me this info.
Hahaha..how the hell did I miss that?? everyday on this site and there are still threads I see first time..
Rich
What about Interface? Do we have the same problem if left on the restoration longer than rec.?
Thanks
Alan
On 8/22/2015 at 9:01 am, Alan Ray said...Rich
What about Interface? Do we have the same problem if left on the restoration longer than rec.?
Thanks
Alan
Alan, I have always beeen told that interface should be placed and used immediately (within 10 minutes or so. Flem has used it as long as I have so he can comment). I've been using the etch and prime from ivoclar also recently. Nice stuff too. anything to get rid of the HF acid is all good with me!
On 8/22/2015 at 10:12 am, Richard Rosenblatt said...On 8/22/2015 at 9:01 am, Alan Ray said...Rich
What about Interface? Do we have the same problem if left on the restoration longer than rec.?
Thanks
Alan
Alan, I have always beeen told that interface should be placed and used immediately (within 10 minutes or so. Flem has used it as long as I have so he can comment). I've been using the etch and prime from ivoclar also recently. Nice stuff too. anything to get rid of the HF acid is all good with me!
+1
Rich
I love interrface.
Is there a risk of over ectching with the interface? If so, what is the amount of time you would suggest leaving interface on the restoration before drying?
Thanks
Alan
