Lithium Disilicate

doug

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I have a doc who asked about it. I can do it, he has accepted his responsibility in the prescribing. I though Dicor was neat 25 years ago. With the new resin cements it would probably be a good product now. Oh yeah, I had Kulzer's Dentacolor...made great blockout material.
 
rkm rdt

rkm rdt

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...and bruxzir would be?

A restoration that I would never recommend to my Drs.
 
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anne2010Ma

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yes, the 400 Mpa is for a fully anatomic pressed e.max restoration. e.max that is cut-back slightly and layered with enamel, the bulk of the restoration is still lithium disilicate (at 400 Mpa). e.max ceram porcelain is about 95 Mpa (as is all or most layering ceramics). even with a slight cut back and enamelization, this is still a very strong restoration. i attached the website with just about everything you could ever want to know about lithium disilicate. Ivoclar Vivadent | The World Speaks e.max

Hi sixonice,

thanks for the reply. I was looking at the website you provided on lithium disilicate. I don't understand the chart. What is under "Examiner" in the IPS e.max® Flexural Strength chart?

Sorry, but I am a little ignorant about the strength of material. I was wondering if there is a website that shows all the strength of each material that you listed below:

"Empress Esthetic is 160 Mpa (must be bonded!) Lithium Disilicate Pressed restorations are 400 Mpa, milled Lithium Disilicate (CAD) are 360 Mpa, zirconia substructures are 900-1200 Mpa (depending on which zirconia & what your reading),feldspathic restorations are 90-100 Mpa, layering porcelains (for zirconia & alloy) range from 90-110 Mpa depending on the manufacturer, alumina substrates are 450-500 Mpa."

Thank you!

Anne:confused:
 
rkm rdt

rkm rdt

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" Okay, I'll play, why not? "

I think there is the question of the long term wear effects on the opposing teeth.What is the hardness or Zir compared to enamel?

Are these restorations being substituted because of the high price of gold?

What about placing a Bruxzir crown on a vital tooth? The possibility of an endo creates a nightmare for the Dr.from what I have heard.

Where are we placing these crowns?...2nd molar I assume.

If strength is an issue and a lithium disilicate is too risky then a gold crown would be the best option in regards to minimal occlusal clearance in my opinion.
 
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paulg100

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The argument for wear rates for FC zirconia at the moment is that abrasion is what causes tooth wear, not the flexural strength or vikars hardness of the material.

Theres some early data starting to filter through from some of the dental companies regarding this, which suggests that a glazed and highly polished zirconia contact is much less abbrasive than enamel, so therefore the wear should be less.

If the crown has proper centric stops and anterior disclusion then really there should be very little to wrorry about. Prescribing for buxers though! really not sure about that one.

So this is the argument right now.
 
rkm rdt

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How many of these crowns are made from a triple tray impression?
 
sixonice

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the problem i have with the full contour zirconia is the fact that when a dentist makes even a very small occlusal adjustment and is not extremely careful to really bring that surface back up to a highly glazed, very smooth surface, these things will be like sandpaper to whatever they oppose. esthetically there are better options and from a strength standpoint there are other options. if a dentist prescribes one to me i will first make the point on if they adjust polishing intraorally is vital, then i will go on to tell them about other alternatives that i feel would be better. if they insist on the full contour, then i have one made.
 
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paulg100

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"when a dentist makes even a very small occlusal adjustment and is not extremely careful to really bring that surface back up to a highly glazed, very smooth surface, these things will be like sandpaper to whatever they oppose"

Ditto.
 
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anne2010Ma

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I believe you are 100% correct and I agree with you. Here is my slice: True, Zirconia substrates are super strong (900-1000mpa depending on what you read). On a layered zirconia, you are correct the weak point is the interface between the zirconia and the build up of glass (90 mpa-like you said). Failures would come in the form of delamination of the ceramic off the zirconia. Now take a Lithium Disilicate, full press at 400mpa, no interface. Both are conventionally cemented. For single units its a no-brainer-the Lithium Disilicate would be better (and MUCH more profitable for the lab!!) Its like comparing 2 bricks that have mortar in between them versus a SOLID brick with no mortar. Zirconia shines on long span anterior bridges and posterior bridges. The substructure design is aso vital in zirconia, where proper support must be adhered to to give the layering ceramic proper support.

Hi Sixone,

so there's no website that shows the above strength of each dental material that you mentioned above? Is this just common knowledge and I just didn't know about it. The reason why I am asking about it is because I don't want to tell my doctors about it and then if I can't show them proof they will think I am making these facts up.

-:confused:A
 
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paulg100

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yes its common knowledge although the figures do vary,

ie feldspathic procelain 90-110-120

zirconia anywhere from 850 to 1600

emax (LS2),ok ill confuse things more - 260-400
alot to do with if its milled/press, how its finished ie smoothed with rubbers etc..

anne2010ma - search about and read, read , read. All the studies and info is in the public domain, you just wont find it all in one place. well apart from here now :)
 
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dmonwaxa

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"so there's no website that shows the above strength of each dental material that you mentioned above? Is this just common knowledge and I just didn't know about it. The reason why I am asking about it is because I don't want to tell my doctors about it and then if I can't show them proof they will think I am making these facts up."

Anne2010Ma

One of the things you'll find out sooner or later is that you're gonna have to do a lot of research on your own,,,,and this (DLN) is a great place to get feedback and opinions. Now, on research most of the stuff may not be readily available and thats why I said "research", you're gonna have to do some digging. Google searches help, but they're ranked and you may have to go down the ranking to find what you're searching for. You asked a question of what a particular column meant on Ivoclar'rs chart; those are people or agencies or universities who investigated the materials, and posted their findings. ( forgive me if this was already explained.) I recommend you go to each manufacturers website and check out their specs regarding a particular material. Companies that produces many such as Ivoclar may require you to look at each material individually to ascertain the information you're looking for. No it's not gonna be easy and as the saying goes "if it's worth it, it usually isn't". But I think you'ld be well prepared to answer those questions when they arise. Dont be discouraged hang in there.
 
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anne2010Ma

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"so there's no website that shows the above strength of each dental material that you mentioned above? Is this just common knowledge and I just didn't know about it. The reason why I am asking about it is because I don't want to tell my doctors about it and then if I can't show them proof they will think I am making these facts up."

Anne2010Ma

One of the things you'll find out sooner or later is that you're gonna have to do a lot of research on your own,,,,and this (DLN) is a great place to get feedback and opinions. Now, on research most of the stuff may not be readily available and thats why I said "research", you're gonna have to do some digging. Google searches help, but they're ranked and you may have to go down the ranking to find what you're searching for. You asked a question of what a particular column meant on Ivoclar'rs chart; those are people or agencies or universities who investigated the materials, and posted their findings. ( forgive me if this was already explained.) I recommend you go to each manufacturers website and check out their specs regarding a particular material. Companies that produces many such as Ivoclar may require you to look at each material individually to ascertain the information you're looking for. No it's not gonna be easy and as the saying goes "if it's worth it, it usually isn't". But I think you'ld be well prepared to answer those questions when they arise. Dont be discouraged hang in there.


Thank you for responding with the great feedback! I will do the research.

Anne:)
 
dmonwaxa

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Anne, your very welcome.... Let us know what you find out.Now go burn the midnight oil. Nthere's gonna be a test.
 
Artexperience

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You got that right!
It seems like all the trade magazines are trying to shove $75,000 milling units down our throats like their the cats meow of dentistry.
Ive out sourced a few maryland bridges. Close to $300 for one pontic and 2 wings.
Hello
I think I may have read a post from you a while back but I can't seem to find it now.......
We have done a zirconia maryland bridge and applied a porcelain wash to the lingual side of the wings, We then etched it. My question is "do you know what steps the Dr should take in cementing?" He's asking if he should do the "bonding step" before cementing?
 
JayH

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Wow, there's an old thread.

I'm surprised no one brought up the strength of natural dentition during that discussion... :)
 
CreativeTech

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Wow, there's an old thread.

I'm surprised no one brought up the strength of natural dentition during that discussion... :)

Likely because they don't know, and hence don't understand the importance of knowing. Most Docs don't know, either. It's disconcerting that this is something not widely discussed. But that wouldn't play to the marketing schemes of manufacturing companies now would it?
 
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