Fractured izir bridge

[dmonwaxa]

I bet the fracture was there after milling and you missed it. I would also check the circumference of the nearest fixture and check thickness around it. By chance is the nearest fixture very divergent? When we do the strategies we set the cam not to go into the holes as it's doing the fine milling and do a separate for each holes slowing down feed rate and rpms. The ones I have had fracture were 100% my fault.

Not quite sure I'm getting you, draw me a picture,,, please?

 

[CreDes]

I had this happen a couple of months ago. I thickened the area and it solved the problem.

 

[prestige.dental]

Hello John

When u are talking about a crack in the presintered state, is it a crack that can be seen by eyes or u would need loupes or microscope.
Is there away to recognize the cracks.

Well after 3 days of unrest and investigation, getting feed back from dln and cap, following were the problems discovered:

1) the tech who painted the bridge with zz water stains made the mistake of putting the bridge into oven only after 5 min!


Since the coming of caps multi FZ preshaded pucks, the coloring and drying step of zirconia had been forgotten in our lab and this was probably the reason of mistake.

2) we have been using Ivoclar programat s1 proprietary P8 setting of 7 hrs 20 min, which is for bridge frameworks. The cooling gradient was too steep and cap told us that the 28mm puck needed a 15 hour cycle with a very very slow cooling rate. So now we have programmed the 15 hr sintering cycle.

3) out of 6, only two sprues were 3mm and 4 were 2mm. In the new design now they are all 3mm.

4) the bridge was placed on the sintering plate flat w/o any beads.
The first bridge, we did was successful, so we did not worry much.

Anyway, the new bridge has been milled and I will post the pictures soon.

 

[Terry Whitty]

Yep it must have been me... I may as well admit it now... will be found out anyway ... .. you are right , darn foiled by punctuation!

 

[Macron Dental Lab]

Hello John

When u are talking about a crack in the presintered state, is it a crack that can be seen by eyes or u would need loupes or microscope.
Is there away to recognize the cracks.

Well after 3 days of unrest and investigation, getting feed back from dln and cap, following were the problems discovered:

1) the tech who painted the bridge with zz water stains made the mistake of putting the bridge into oven only after 5 min!


Since the coming of caps multi FZ preshaded pucks, the coloring and drying step of zirconia had been forgotten in our lab and this was probably the reason of mistake.

2) we have been using Ivoclar programat s1 proprietary P8 setting of 7 hrs 20 min, which is for bridge frameworks. The cooling gradient was too steep and cap told us that the 28mm puck needed a 15 hour cycle with a very very slow cooling rate. So now we have programmed the 15 hr sintering cycle.

3) out of 6, only two sprues were 3mm and 4 were 2mm. In the new design now they are all 3mm.

4) the bridge was placed on the sintering plate flat w/o any beads.
The first bridge, we did was successful, so we did not worry much.

Anyway, the new bridge has been milled and I will post the pictures soon.

I Have a s1 as well if you don't mind can you share the program you used for the s1 thx in advance.

 

[KentPWalton]

I was going to say definitely it wasn't dry all the way. Steam builds up and has to escape somehow.

CRACK!!!

 

[Boksa]

how to get rid from fracture in tooth my front three tooth are just cut from the downside.