One Piece Zirconia Prosthesis for Maxillary Arch: Experience?

I posted the pre-op radiograph for this case a month ago. I am working very closely with a lab with extensive experience with milling Zirconia screw-retained implant prosthesis. I am very interested in the success rates of a zirconia full arch bridge. I will follow up with my finished results.

I have recently completed the surgical portion of the case, no complications. I placed Hiossen ETIII’s on a elderly gentlemen with no significant health history.
I plan on restoring the maxilla with a screw-retained one-piece-Zirconia-bridge.

What has been some of your experiences with Zirconia screw retained prosthesis? What should I be watching out for, and what can I expect. I feel very positive about Zirconia as a good material, just more worried about broken screws in the implants due to zirconia’s strength. My lab knows what they are doing, but I do understand that one piece custom milled zirconia hybrid dentures are pretty new, so not much literature out there. Comments?


Maxillary-Full-Arch-Implant-screw-Zirconia

19 Comments on One Piece Zirconia Prosthesis for Maxillary Arch: Experience?

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CRS
9/15/2014
What kind of prosthesis a screw retained fixed bridge vs an all on five? Do you have an example or photo to post? If an all on four can be done with Zirconium vs metal then less bone reduction would be necessary and that would be a very good thing. If this is individual bridges or is it a hybrid? Are there enough implants to support? Very interesting case need more info thanks.
CRS
9/16/2014
Do you have a photo of the surgical stent, these implant appear to be randomly placed. I don't like to rely entirely on the lab when I am placing. The stent will show what you have planned thanks.
Alex Zavyalov
9/16/2014
The main restoration problem of all full denture cases is to find a proper vertical dimension without lower jaw translation. From this point of view, any zirconium full arch bridge is extremely difficult to fit. I would at least make a lower denture from an acrylic material with Locator system.
mwjohnson dds, ms
9/16/2014
a screw retained bridge, a hybrid, a fixed detachable and an all on four/five/six/seven/eight are all pretty much the same thing. Anything that is screw retained will most likely require angled abutments that reorient the screw access chimneys to the palatal so they don't impinge on the facial surfaces of the teeth. Implant placement is less critical in these types of restorations. Full arch Zirconium seems to be the restoration de jour and is a reasonable restoration. Your abutment screws aren't going to break. You have the implants nicely spread around the arch so there won't be any cantilever forces on the bridge (important for Zirconium or any ceramic material since it doesn't flex) that would overstress the screws. I'm a little concerned about the anterior span between implants that may cause some flexion of the framework under incisal pressures but otherwise the placement seems to be pretty well done. Several challenges: one, zirconium shrinks when it's sintered so you can imagine the challenge of getting it to fit passively across the arch on 5 implants.To attain a passive fit most labs cement metal seating surfaces into the zirconium prosthesis after sintering to correct for the shrinkage. Also, monolithic zirconium is not particularly pretty so labs will either paint on color (pink for gums, tooth colors for the body and incisal of the teeth) and it tends to have that painted on look. Another way to improve the esthetics is to veneer the zirconium with feldspathic porcelain but we know the bond to zirconium is less predictable than to metal so would be more prone to fracture thereby negating some of the pluses of a monolithic restoration. Also, the work up for a monolithic restoration is extensive and needs to be precise since there's no changing tooth positions or occlusion once it's miled. As you can see, full arch restorations are a challenge! There's no magic material for full arch prostheses. All materials have pros and cons. Hopefully all will work out for you.
Btcdentist
9/17/2014
Thank you Dr. Johnson. very important post. I learned alot. Do you think its better option to go with titanium and acrylic? My lab is highly recommending the zirconia, but obviously I want to go with the best option for my patient. Zirconia does seem bulky and heavy and not necessarily esthetic.
nailesh gandhi
9/16/2014
We have done such prosthesis full mouth in zirconia , screw retained both maxillary and mandibular since beginning of this year. Patient earlier had metal frames. We are also eager to know pros and cons with more time. But patient is very happy till now.
Keith Goldstein
9/16/2014
Looks like a straightforward case but there are several workarounds the lab has to do with connecting the zirconia bridge to the multiunits which drive up the cost of the restoration significantly. Hiossen tends to lack the components of other manufacturers for parts such as titanium interfaces/ ti bases.
Dr SSG
9/16/2014
I think MWJ has covered most points..except I don't see a Zirconia bridge flexing much? I also don't see any issue with your implant placements they are pretty good in very good bone. I have mixed feelings about Zirc" ...it can be pretty...but very unforgiving. Would recommend lab do an AVS for you to ensure your master model is good. My only question is.. what are you opposing this large fancy Zirc bridge with?...a plastic over denture on mini Implants?...kinda like cheap tyres on a Ferrari? Personally I feel that you have quite an imbalance of forces between upper and lower potential prosthesis...upper is classic and will be good regardless of what you use ...perhaps save a few bucks on the fancy lab and get patient to place standard implants in lower posterior mandible ...its not as if you don't have the bone!Good luck
btcdentist
9/17/2014
Thanks Doctor for advice. Will be removing the lower mini's and implanting 4 hiossen ETIII's. Will do an milled bar screw retained acrylic denture or locator system.
Rob Smith
9/17/2014
I've done about 10 of these cases. Half with a local lab and half with glidewell. There is no doubt that glidewell has this process mastered. They provide everything you need including the angled abutments. I don't know how they do it, but in every case I have done the final restoration has fit with complete passivity. If they don't fit passively there is a fairly high chance that the hybrid will fracture. It is a relief to know that the final prosthesis is going to fit. The only caveat is that I have not used glidewell for a case with high esthetic demands. I am not sure if they cut back the zirconium and bake porcelain over it. Either way, zirconium is far superior to a bar with denture teeth. Another caveat is that they screw directly into the implant (unless it need an angled abutment) and this means that the patient is uncomfortableduing the try in appointments.
btcdentist
9/17/2014
Thanks Dr Smith. what would be your pro/cons list for zirconia vs bar? also how are the outcomes of both zircon vs zircon max vs mand.?
Tuss
9/17/2014
The full arch zirconia frameworks are quite heavy and bulky, sometimes a metal framework is also bonded to the zirconia meso structure. Given the reduced number of implants and spacing, I would consider a milled bar-over denture option or an acrylic veneered milled bar - what are you doing in the lower - strongly recommened you do not make zirconia fixed full arch vs another zirconia milled full arch
Btcdentist
9/17/2014
Hello, Yes the bulk and weight of the zirconia does concern me. Especially the maxillary. What are the pros and cons of a zirconia vs titanium bar? The titanium bar w high density resin is so much lighter but more prone to fracture. Zirconia is one piece but seems very heavy and bulky. The trend is leaning towards zirconia, but, should they only be considered for the mandible?
DrT
9/18/2014
Define "elderly gentleman". If your patient is 79 years old and had been in dentures for 20 years, metal/acrylic would have been fine. If esthetics are a huge concern, I prefer 8 implants suporting four separate 3unit FPDs, but Ialways prefer multiple smaller restorations over one large horseshoe. Granted, Zirc isn't supposed to break, but again if you're opposing an acrylic mandibular denture, then Zirc isn't needed on top because the worst bruxer isn't going to break something against acrylic except maybe acrylic.   The biggest concern I have with this case is the sentence "My lab is highly recommending the zirconia". Why is the lab recommending it? You are the doctor. Are YOU recommending Zirconia? If so, why?   NOTE: These comments are not meant to be derogatory in any way. This is simply a learning process, and sometimes uncomfortable questions need to be asked. If I offend anyone, please forgive me.
mwjohnson dds, ms
9/23/2014
sorry, been out of the loop golfing. enjoying the posts. I don't use acrylic in the maxilla anymore and not much Zirconium. I have started using the Bredent composite denture veneers for my "hybrid" restorations. These veneers set up like denture teeth, then a titanium framework is CADCAMed under the veneers then they are composite bonded to the framework. I describe it as a reverse PFM meaning the facings are positioned for esthetics and function then the framework is made secondarily. These prostheses are light as a feather compared to Zirconium and have a little give to them since they're composit. They wear significantly better than the traditional acrylic teeth processed to a metal platform or frame. In the maxilla, the forces are outward which quickly fractures the acrylic teeth from the prosthesis. With the titanium directly beneath the composite veneers, the occlusal force is on the titanium, not on the veneer. Go to the bredent website to learn more about this great technology.
Tuss
9/24/2014
Biomet 3i BellaTek sure bars have a similar technique where composite veneer facing are applied to the framework to produce a really nice aesthetic result, ask your local rep - a couple of Italian guys developed the technique and I think they have it set up with 3i, appologies but the name escapes me just now but the aesthetics are great
David Broughton
10/8/2014
As a technician ceramist working extensively with both PFM and Zr, I have become more inclined to Zr. When we were first working with Zr, there was very little literature regarding the do's and don'ts, and yes we had ceramic chipping, particularly on posterior marginal ridges and spade shaped central incisors. In other words areas of ceramic that were probably less supported. Gradually, we learned by our mistakes. Also when Zr is adjusted (ground), it should be accomplished with low speed and be well irrigated. Then blasted with aluminium oxide @ 4bar. What is not very well publicised is that the Zr bridge framework should then be heat conditioned to reinstate all particles to their original orientation, which would have been disturbed during grinding. A minor adjustment to the margin line on a single coping, would not require this heat treatment, but all bridgework should! Full arches absolutely! Slow cooling imperative. I do agree with the sentiment of cementing Zr frameworks to Ti links, even for screw retained prostheses. No screw pressure on the Zr. I know we technicians don't have the same experience of cementing, but at least we don't have the patient to contend with!
Rick Stanley
10/9/2014
What labs are people using successfully on these cases?
Sharon Goodwin
10/13/2014
Hey Rick!! Great to see you on Osseonews!! I am going to make enquires anout the bredent option!!

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