Vita zirconia flexursl strength increased over the years ??

[dabza]

Hello guys

Can someone explain what changed from 2018 to 2022 in vita zirconia manufacturig and components for its flexural strength to increase dramatically as shown in the following pictures :

 

[Car 54]

Maybe the material science improved? We went through this about 5-7? years ago, where emax press was originally rated at ~350mpa then jumped up to ~450-500mpa. I think it was partly to compete with the other pressables that were stronger. I I remember Ivoclar's reasoning at that time was, "we've been having such good success with emax that it must be stronger than we thought". I also believe Patrick Coon may have had a different explanation. I think the measurements were at 1mm thick.

 

[dabza]

Maybe the material science improved? We went through this about 5-7? years ago, where emax press was originally rated at ~350mpa then jumped up to ~450-500mpa. I think it was partly to compete with the other pressables that were stronger. I I remember Ivoclar's reasoning at that time was, "we've been having such good success that it must be stronger than we thought". I also believe Patrick Coon may have had a different explanation. I think the measurements were at 1mm thick.

If the the tests were applied on 1mm thickness , i would agree , just i want them to clarify and mention it somewhere. Because the way they changed it was sneaky a bit (kinda sus) .

 

[Car 54]

I was skeptical of Ivoclar's revised numbers as well. It's like the Glidewell Bruxzir test of hitting a molar crown with a hammer in a block of wood, pine? was at 1 or 1.5 mm thick, and not a thinner "you can get by with this occlusal gold like thickness" amount in the posteriors.

 

[dabza]

I too hate the hammer tests the force applied there doesnt exist inside my mouth . my jaw uses compressive force not impact force , it is what im afraid of . They just love hammering stuff like a toddler .

 

[Car 54]

I too hate the hammer tests the force applied there doesnt exist inside my mouth . my jaw uses compressive force not impact force , it is what im afraid of . They just love hammering stuff like a toddler .

Good point, and funny

 

[grantoz]

emax got stronger by going from a 3 point test to a biaxial test which has a 3 point triangle formation one side of the test blank and load applied in the middle on the other side so of course the number is bigger they did this to match their competitors they also made the sample thicker. always read the fine print.