Chipping on implant crown margins

[tehnik]

There is a core update for millbox, may be get it from your reseller or ask cims to send it to you. Try updating it and if it fix this issue. ( i got it from cims like two weeks back)

You can download the core updates from their homepage and I have done it. There is no change of outcome.

 

[JeffT]

I actually started have the same exact problem with jobs that have ti-bases. They are very tight. This is with millbox v22 bevore I had 20 and no problems.

I have actually gone back to my 2019 vers of Millbox. The crowns and implants are finishing much nicer again
Not sure what is happening.
The 22 vers is way to aggressive.
I can hear the mill bogging down a little as it starts with the 2mm bur. I never had that sound in the older version. The margins were chipping and the surface finish is rough. The crowns are milling much nicer again since I changed the 1 and 2 mm burs in 19.
I will speak to my support and try and figure it out.

edit.....I had already replaced the burs in 22 vers

 

[JeffT]

You can download the core updates from their homepage and I have done it. There is no change of outcome.

Did the updates help with your issues?

 

[tehnik]

Did the updates help with your issues?

No difference.

 

[JeffT]

Sorry for delay replying.
So...i went back to 2019 which was much better. Am now on 2020 vers of Millbox. chipping seems to have ceased but still had issues with tight fits to the ti bases. checked and rechecked strategies / burs etc and slowly dialing it in. Fits are still tight but better. I have adjusted the Cavity Fit to 0.02 to see how that goes. I don't think I can adjust the die spacer with the OEM DME's? I have looked but didn't see it when designing.
Will transfer everything over to 2022 when I am happy with everything.
Been a bit of a pain but will get there soon.

 

[Scott Bradley]

Hi all....
Haven't posted for quite some time.

Having a problem with Occasional chipping on margins. Sometimes they are perfect and other times chipping.
I milled 2 crowns back to back yesterday. One chipped and the other was fine.

Both are Straumann wn. Mill is a DX52 with newish burs, calibrated and cleaned weekly and DME are current.
Cam is millbox.
The only difference was with the disk sizes used. Upper molar was in a 14mm and the lower was in an 18mm.
Any ideas appreciated.
See pics.
Lower molar is first pic and milled perfect.

Thank

I know this is an older post but I thought I would post my experience that I had last night and tonight. I had literally the EXACT same problem with millbox but my machine was a DWX51D. My implant/hybrid crown was 11.54mm tall, I put it in a 14mm disc and machined with broken margins. Then I redesigned and tried again in a 14mm disc. Broken margins. I milled all of my other crowns with perfect margins. So I re-marked the margins in millbox and tried again. Broken margins. I came here to see if anybody else had had this problem. I saw your post about the 18mm disc working. I tried that and I had success. I have milled 14 other crowns since then, all with perfect margins. I have been milling with millbox for 7ish years and have never had this problem. If anybody else has a solution, I would love to hear it! Thank you for this post!!!

 

[Scott Bradley]

I was thinking about what I posted earlier and I said I had used millbox for 7 years (I think) but I realized I was wrong. I started using millbox in 2018 and was using Sum3d before that. Not relevant, but I just wanted to be accurate. Also, I don't visit here enough. There is a TON of good info!

 

[zero_zero]

I know this is an older post but I thought I would post my experience that I had last night and tonight. I had literally the EXACT same problem with millbox but my machine was a DWX51D. My implant/hybrid crown was 11.54mm tall, I put it in a 14mm disc and machined with broken margins. Then I redesigned and tried again in a 14mm disc. Broken margins. I milled all of my other crowns with perfect margins. So I re-marked the margins in millbox and tried again. Broken margins. I came here to see if anybody else had had this problem. I saw your post about the 18mm disc working. I tried that and I had success. I have milled 14 other crowns since then, all with perfect margins. I have been milling with millbox for 7ish years and have never had this problem. If anybody else has a solution, I would love to hear it! Thank you for this post!!!

It usually happens when the finishing tool goes too deep into the hole from the bottom side and hitting the margin with the tapered part, check your strats and the Z limit on that operation, possibly move the crown all the way to the top of the disk to prevent it. Or use longer reach tools.