Death by Zr

[TheLabGuy]

I see that your advocating Emax or Metal ceramic, just out of interest what alloys do you routinely use in the lab?

I'd bet base metals....HA!!!

 

[charles007]

Lies, damn lies and statistics, are we talking about Obama or ceramics ?

 

[rkm rdt]

Obama is disturbed?.......smooth,yet abrasive!

 

[charles007]

Obama is disturbed?.......smooth,yet abrasive!

AND HE LIES

 

[user name]

Dont forget...83% of statistics are made up on the spot.

 

[charles007]

To put a different spin on using full contoured zirconia, has anyone thought about the shock/impact on the opposing teeth. Anyone read anything on this subject ?

 

[e...w...h]

Dont forget...83% of statistics are made up on the spot.

 

[disturbed]

Hi Disturbed,

Interesting comments.

Two quotes spring to mind when reading this post

There are three kinds of lie: "Lies, damn lies and statistics"

and also:

"For every solution, a new problem"

The great thing about Dental Technology is the fact that you never stop learning and never stop developing your skills, I look back at work that I was highly pleased with 20yrs ago and cringe now, thankfully I've progressed and also learn't some humility along the way.

10 years isn't along time in this business, technicians are always being sold the latest, best, cutting edge solution to aesthetics, cost, or speed of manufacture, ask your mentor to list off the various "wonder" materials that he can remember using in his life time, and then see if you've heard of them.


All ceramic is certainly here to stay, Zirconia is only one solution available to restore teeth and is not suitable for every case.


Hardness and wear rates are only part of the problem that we may creating for the patient.

I see that your advocating Emax or Metal ceramic, just out of interest what alloys do you routinely use in the lab?

What life span do think the average metal ceramic crown or Emax crown has?

In the lab that I am currently working at we use capricorn alloy from Ivoclar, I do not particularly like it because of its affinity for carbon, margin creep, and the fact that palladium is carcinogenic. But as gold passed 1700 recently it is an economical choice that our clients appreciate.

I prefer a silver free alloy like 65 SF from Argent, much more gold than that and it becomes VERY technique sensitive. for my FGC's I prefer a 58% as it polishes nicely and casts well. but again, clients are hesitant to pay unless they are old school and appreciate a bio friendly material, this includes WEAR..

I appreciate all ceramic, a lot, and with some slight perseverance I am hoping to share my reasons for choosing a good all ceramic, NOT Zr.

Regarding life span, this all depends on the technicians approach and functional information, as people are seeing, even layered Zr with NO chemical bond will last longer with correct support. A full contour Zr will probably outlast anything currently on the market, and as it slowly changes the function and destroys the surrounding dentition it will most definitely outlast the surrounding natural teeth.

please, if you are calling me a liar, quote what you think is a lie and I will provide my proof for you.

we had an issue with Eris. Did LOTS of them,we got Ivoclar to admit the problem after thorough documentation and reimburse our clients for re-make costs. Ultimately we are responsible for getting feedback and making right any failures that occur from our materials, or at least not choosing those materials in the future.. At least we should be.

If its built correctly on a full arch model there is NO reason for any and every material not to last 20-30 years as long as the material is sound.(full arch model so we are provided with function information) Full arch model for a single...HA!..ya I know, it's rare. But when explained to the dentist the reasons for them I have had very good success in getting them for ALL cases.

I am humbled by critiquing the work I did 10 years ago, I will continue to grow and learn, applying what I learn to my choices in current and future materials. I am hoping to teach what I know to others so they may make a good material choice that will assure our patients get a crown that will last 30 years without causing trouble to the surrounding teeth.popcorn

 

[rkm rdt]

"please, if you are calling me a liar, quote what you think is a lie and I will provide my proof for you."

"I, and the fact that palladium is carcinogenic.a'

Prove it!

 

[adamb4321]

told my doctors, they quit using the stuff, all of them:

I thought you worked for someone, surely they are not really your customers? Maybe the dentists just send the zircoia somewhere else?

So your happy to supply Palladium based alloys despite believing they cause cancer?

Have you told your customers this too? How about the toxic effect at a cellular level of the various dentine bonding agents ?

I'm not calling you a liar,however, in some of your posts you do make some very bold statements about your ability which based on the photos you posted is competent but average, in fact just like most of us.

Looking back at your first crowns from 10yrs ago and realising that they aren't perhaps as good as you thought is ok, when I look back 20yrs at my work I already had 7 years of experience, had worked with some top techs and attended loads of courses and thought I knew the lot, in another 10 or 15 yrs you'll look back at the crowns you made today and realise how far you've travelled.


The quote "lies, damned lies, and statistics" is more about statistics and perhaps not taking everything you read as gospel. For every study saying one thing there are generally three more saying the opposite.

Yes, we have all seen crowns that have lasted 20 or 30 years, this is not the average life span of a crown though, mass produced crowns perhaps on average last between 3 and 5 yrs and if they get to 10 yrs old have done quite well. PFM's fail with startling regularity and as with most things failure is generally down to poor design/ poor selection of suitable restoration rather than a material failure in itself.

 

[disturbed]

"please, if you are calling me a liar, quote what you think is a lie and I will provide my proof for you."

"I, and the fact that palladium is carcinogenic.a'

Prove it!

fourth paragraph down on HEALTH EFFECTS OF PALLADIUM.....Palladium (Pd) - Chemical properties, Health and Environmental effects

not "happy" i use this metal, but I am a simple slave to the man....

 

[disturbed]

back to topic... simple to understand. Zr is destructive to crowns and natural dentition. If my rock in a bag of chalk analogy is not clear enough let me know and I will continue.

remember when they would use gold crowns in compromised situations (parafunction) to prevent wear to the opposing natural dentition? I don't.... but one of the old guys told me about it...

 

[harry1]

Only one solution, whip em all out and give them a denture, long live removables!

 

[rkm rdt]

fourth paragraph down on HEALTH EFFECTS OF PALLADIUM.....Palladium (Pd) - Chemical properties, Health and Environmental effects

not "happy" i use this metal, but I am a simple slave to the man....

Biocompatibility of Dental Materials By Gottfried Schmalz, Dorthe Arenholt-Bindslev

Biocompatibility of Dental Materials - Google Books

 

[rkm rdt]

Seems there is inconclusive information on the carcinogenic properties of palladium.I found studies on both sides.

However Zirconia is,as you know, biocompatible.Therefore at the risk of further embarassment ,I suggest you change the title of this thread to "Death by Palladium"

Checkmate.:caked:

 

[e...w...h]

back to topic... simple to understand. Zr is destructive to crowns and natural dentition. If my rock in a bag of chalk analogy is not clear enough let me know and I will continue.

remember when they would use gold crowns in compromised situations (parafunction) to prevent wear to the opposing natural dentition? I don't.... but one of the old guys told me about it...

The rock in a bag of chalk analogy doesn't hold water... one suggests completely free movement where the "rock" touches all chalk and one is microns of movement over a long period where only a few teeth are in contact (or not) with the zirconia. It is an extreme view and makes some sense, but the length of time it would take to create havoc (or not) is completely hypothetical.

 

[harry1]

[Only one solution, whip em all out and give them a denture, long live removables!]

Prehaps we should leave them in and cap them after all, look like fixed is back in the frame!

 

[CoolHandLuke]

why not have one-piece implant supported 14 unit upper lower full anatomical zirconia ?

not feeding the troll - serious... why not? no significant wear to speak of, will last naturally longer than the patient.

 

[k2 Ceramic Studio]

why not have one-piece implant supported 14 unit upper lower full anatomical zirconia ?

not feeding the troll - serious... why not? no significant wear to speak of, will last naturally longer than the patient.

I have seen a few cases like this come through the lab, there is no real way to get it spot on! Full Zr looks a bit naff-no life to it (you guys have done some great singles but I am talking about a 14 unit bridge all stain and glaze) plus a shed load of weight, now I know that once it's screwed in who care about the weight but it's still there! you can overcome this with a thick Ti bar to reduce some of the mass thus have less Zr but still looks naff, the only way I could see you doing it would be to have a full denture wax up over implants, just for the shape don't shoot me!!!!!!! make sure the try-in goes well then scan the thing over a Ti bar to reduce the mass and use some sort of cut back software to reduce the gum areas and faces of the teeth, or just grind the crap out of the denture before you scan it but leave the occlusal table. Mill it in Zr then Slow sinter 14 hours, this thing is going to be big. Then re layer the faces, just like doing a large veneer case and replace the gum areas with your choice of pink ceramic.

Not trying to show anyone how to suck eggs this is just my idea of how you could do a full upper or lower or both, implant supported bridge/s using a Zr occlusion and still have some aesthetics.
Now the occlusion would still look naff but the overall aesthetics could look very nice and the Ti would keep the weight down, When I have a bit of time and a dentist and patient that want to try it then I will give it a go and post the results.

 

[CoolHandLuke]

at one point in my own life i was almost to the point of putting in 4x 4unit posterior implant supported full anatomical zirconia bridges into my self. i have bad teeth i still had my 8's and my 4&5's hurt like hell... when i got work done however my dentist relieved my pain with extractions (removed my 8's) so it never got to that stage, tho i was fully prepared to endure it.

when you and so many other people complain about occlusion however i am wondering if i'm doing something different from you or what... i am just the guy in the middle of the process, i am not the finishing ceramist i just design the crowns, but i haven't had a complaint about occlusion anatomy on my designs for a while... i'm going to have a company meeting soon and this will be one of the points i bring up to discuss... i'll let you all know what the outcome is...

something is definitely wrong; my ceramists arent complaining... (yes i know its a bit Off topic - just hold that thought for a few more days...)