Screw Retained Crowns?

[ParkwayDental]

Ok what and how do you guy's feel about a posterior screw retained crown being all one piece instead of being cemented on to the Ti interface?

I have a doc that wants a screw retained crown but wants the interface to be out of zirconia so the restoration is all one solid piece of zirconia?

Personally I would rather cement the restoration on to a Ti interace but he is nervous about that.

 

[CoolHandLuke]

all zirconia is too weak, it breaks easily. its always toooooo small. the titanium is stronger for those tiny connector areas. besudes which, if the implant is deep enough, there will not be any grey line. make sure its a nice 2 mm sub g and you're golden for esthetics even with titanium.

 

[zero_zero]

I'd rather have a Ti interface instead of an engaging Zr part... made a few by request...now crossing fingers... Did a few short span FCZ screw retained bridges ( non engaging flat bottom ),those were fine...

 

[ParkwayDental]

That is how I feel about it I warned him and told him I could not warranty the case. All I have done is one to a Ti interface with Ivoclar Multilink Cement and he just won't go for it. Damn dirty sales rep talked him into doing it the way he wanted! He said that is fine and he would send it to someone else but hey at least it won't be my ass when it breaks. ray2:

 

[actittle]

We have done several of them without any issues.

 

[sidesh0wb0b]

i am with Luke, id prefer the Ti platform......BUT, we are a service industry. you expressed no warranty, give the Dr what they want. ive done it both ways with no issues either way, but the phone call still has to be made. sounds like you already did all you could, pray that he seats it properly and all goes well. then it will be a success and he will want more More MORE! hahahaha

 

[ayane]

All Zirconia should be more than adequate.

 

[PDC]

I've done a ton of them thru Atlantis with no problems. Warranty is for 5 yrs. which is pretty much standard for zirconia abutments among other manufacturers.

 

[BobCDT]

Yes, five year warranty is about right. Zirconia looses 50% of its flexural strength over five years.
Recent studies have shown that zirconia interfacing with implants results in wear of the titanium implant.
We've had failures of zirconia interfaces. We discontinued all zirconia products that screw directly to the implant.

 

[Al.]

Ditto I will never make a abutment with a all Zir interface. Had to many failures even on laterals.

 

[Al.]

As far as posterior one peice screw retained crowns I do them all the time but metal ceramics on cast ucla abutments. They are sooooo easy and still charge for a crown and abutment.

 

[ParkwayDental]

Is there any published literature about all zirconia interfaces starting to fail?

Al do you ever do any hybrid type abutments?

The problem I have is the sales rep is out bashing our lab for cementing a zirconia abutment to a Ti interface and is telling him we are wrong for what were doing? He told our Doc he needs to send it to a different lab. I mean really wtf?

 

[CoolHandLuke]

you may want to retort by asking him why he currently has a deskjob and then pointing out it was because his work quality when (if) he worked in a lab was complete terribad and dumbholes like him don't deserve the time of day because they obviously "know" jack squat. also they live in a VAN DOWN BY THE RIVER ><

 

[Al.]

I've made a few , i buy the inserts made to cement Zir onto and wax and press emax to bond to it.
Ivoclar has a kit for that.
Implant direct has some brands for 60 each. They are basiclly stock abutments but with thinner walls so they have a nice wide shoulder at the base and they have retention ridges to bond better.
Glidewell has several different inserts or bases to make hybrid abutments or screw retained hybrid crowns.

 

[Al.]

I've made a few screw retained emax crowns. It's just a emax crown with a access hole in it. I put a bur shank into the abutment then wax the crown around it . I use occlusal forms so I put a hole in the form.

 

[PDC]

Is there any published literature about all zirconia interfaces starting to fail?

I think success boils down to making informed decisions based on the clinical situation at hand. There are a lot of variables involved ie. location, bite forces, platform size, external hex, internal hex, bridge span, torquing the screw properly, and on and on. Warranties are based on failure rates...the doctor should know that a shorter warranty period should be one factor in the type of abutment that needs to be placed.

http://www.straumann.de/content/dam...tsammlungen/Abstracts_ZrO2 Abutment 32012.pdf

 

[disturbed]

moh hardness of zr is MUCH harder than ti. It WILL wear, wear the ti, wear the opposing tooth. period. simple to understand.

flucking zr...oye.

 

[Sevan P]

Also image all the force the ZR interface is taking when the Doc torques the screw in. Ti interface and cuts your chances of redo down by a little bit. If the bridge is going to fail it will but with the Ti interfaces it has a better chance at a longer life, that's my $0.02.

 

[sidesh0wb0b]

Is there any published literature about all zirconia interfaces starting to fail?

Al do you ever do any hybrid type abutments?

The problem I have is the sales rep is out bashing our lab for cementing a zirconia abutment to a Ti interface and is telling him we are wrong for what were doing? He told our Doc he needs to send it to a different lab. I mean really wtf?

i know there are at least a few other articles, but heres one....
Wear at the titanium-titanium and the titanium-zi... [Dent Mater. 2012] - PubMed - NCBI
"Titanium implants showed higher wear at the implant interface following cyclic loading when connected to one-piece zirconia implant abutments compared to titanium abutments. The clinical relevance is not clear; hence damage of the internal implant connection could result in prosthetic failures up to the need of implant removal."
Copyright © 2012 Academy of Dental Materials.

 

[corona]

Yes, five year warranty is about right. Zirconia looses 50% of its flexural strength over five years.
Recent studies have shown that zirconia interfacing with implants results in wear of the titanium implant.
We've had failures of zirconia interfaces. We discontinued all zirconia products that screw directly to the implant.

bob , thats a bold statement you just made : Zr loses half its flexural strength over 5 years . Please back that up .
My question is : does it continue to lose flexural strength after the 5 years ? Am i worried about nothing ?

corona