Katana... Thoughts after using it for awhile
I have had mixed feelings about the Katana (especially vs e.max cad) since using it. On one hand, the Katana STML looks and fits fantastic. On the other hand, you can expect it to take a good 20-25 min longer than a typical e.max (if glazed) and a little less if polished. I have gone back and forth if the time is worth it. After using it for awhile, I found myself starting to go back to e.max CAD due to the time. After a little more thought and clinical results, I have decided that in a lot of cases, it's worth the extra time. The stuff just looks and fits fantastic...AND there is better detail.
That being said, the other question is should you glaze or polish. I have done both and they both work out nicely, but I have realized that you have to be a bit careful about shade when deciding how you want to finish it.
As a general rule of thumb... polishing zirconia tends to produce a pearl effect, but it ALSO will lower the value. For that reason, I would tend to choose a shade that matches the shade you are trying to achieve (when polishing). As you can see in the slide below, the company recommends one shade brighter when polishing due to the decrease in value... but that might be overkill.
If you are glazing, It will increase the value and make it brighter. In that case, I would choose a shade one to maybe even two shades darker than your target shade.
Here is a case that illlustrates that. Both were done in A3 Katana STML. Tooth #13 was polished and tooth #14 was glazed. Both were clinically great... but notice the lower value of tooth #13 that was polished.
I hope this helps
Mike could you let us know what clinical cases that you feel Katana is indicated over Emax? Is the fit better than Emax, it seems most of us have had very good fit results with Emax. Is it chance of breakage with Emax the main reason you would use Katana? I have had some breakage with Emax and would say most was operator error. An extra 20-30 minutes of having a chair tied up can add up depending on chair availability, speed of operator, and demands on patients time. Are we having more problems with breakage of Emax than many are willing to admit? Also is cementing vs bonding much of an issue, for some time now the general consensus seems to have been bonding is superior. I guess bonding of Emax is superior because it adds strength to the material and with Katana that point may not be necessary. I would prefer to cement over bond if results are same or better. I am looking into buying an oven to do zirconia and am looking for advice why I would place more zirconia and fewer Emax. Thanks, Jim.
Mike,
Was the prep shade the same for each tooth? I just did an A3 Katana STML and the value changed due to the dark prep shade.
On 4/4/2018 at 9:48 am, Bill Burkhart said...Mike,
Was the prep shade the same for each tooth? I just did an A3 Katana STML and the value changed due to the dark prep shade.
Hi Bill-
I think they were relatively close. You are right though, you have to pay attention to the prep stump shade. The STML is translucent enough to make a difference.
On 4/3/2018 at 6:41 pm, James McCaslin said... Mike could you let us know what clinical cases that you feel Katana is indicated over Emax? Is the fit better than Emax, it seems most of us have had very good fit results with Emax. Is it chance of breakage with Emax the main reason you would use Katana? I have had some breakage with Emax and would say most was operator error. An extra 20-30 minutes of having a chair tied up can add up depending on chair availability, speed of operator, and demands on patients time. Are we having more problems with breakage of Emax than many are willing to admit? Also is cementing vs bonding much of an issue, for some time now the general consensus seems to have been bonding is superior. I guess bonding of Emax is superior because it adds strength to the material and with Katana that point may not be necessary. I would prefer to cement over bond if results are same or better. I am looking into buying an oven to do zirconia and am looking for advice why I would place more zirconia and fewer Emax. Thanks, Jim.
Hi James-
The clinical cases I would choose Katana over e.max would like be those in the posterior that are prepped to the gumline. E.max performs well in those scenarios too... it's just that i'm realizing that Katana just passes the "eye test" . That is, there is more detail in both the contour and the anatomy to make a visual difference over e.max in my eyes. You can make e.max look like that, but it take some hand contouring.
I will say that I cement all of my Katana (against manufacture recommendations at this time). So if i'm preparing a case that will rely more on adhesion, then i'm for sure going to use e.max.
I hope that helps.
On 4/4/2018 at 10:28 am, Mike Skramstad said...On 4/3/2018 at 6:41 pm, James McCaslin said... Mike could you let us know what clinical cases that you feel Katana is indicated over Emax? Is the fit better than Emax, it seems most of us have had very good fit results with Emax. Is it chance of breakage with Emax the main reason you would use Katana? I have had some breakage with Emax and would say most was operator error. An extra 20-30 minutes of having a chair tied up can add up depending on chair availability, speed of operator, and demands on patients time. Are we having more problems with breakage of Emax than many are willing to admit? Also is cementing vs bonding much of an issue, for some time now the general consensus seems to have been bonding is superior. I guess bonding of Emax is superior because it adds strength to the material and with Katana that point may not be necessary. I would prefer to cement over bond if results are same or better. I am looking into buying an oven to do zirconia and am looking for advice why I would place more zirconia and fewer Emax. Thanks, Jim.Hi James-
The clinical cases I would choose Katana over e.max would like be those in the posterior that are prepped to the gumline. E.max performs well in those scenarios too... it's just that i'm realizing that Katana just passes the "eye test" . That is, there is more detail in both the contour and the anatomy to make a visual difference over e.max in my eyes. You can make e.max look like that, but it take some hand contouring.
I will say that I cement all of my Katana (against manufacture recommendations at this time). So if i'm preparing a case that will rely more on adhesion, then i'm for sure going to use e.max.
I hope that helps.
99.9% of my patients will not know this and it's not worth the extra time to choose Katana over Emax for minor details of anatomy in the posterior teeth.
I totally love Katana. The extra 15-20 minutes is a pain but the looks and fit are fantastic. Hopefully it will come done in sintering time. RMGI is easy to use and what we use for all Zirconia
I get it Daniel and that is a decision that all of will have to make for ourselves. Keep in mind that anatomy is in our teeth for a reason. An argument can be made that better definition could lead to better functioning restorations. Just a thought... may not matter
On 4/4/2018 at 3:53 pm, Mike Skramstad said... I get it Daniel and that is a decision that all of will have to make for ourselves. Keep in mind that anatomy is in our teeth for a reason. An argument can be made that better definition could lead to better functioning restorations. Just a thought... may not matter
Hey Mike, my comments are sour grapes. With my CS4 oven, it will take 2 more hours not 20 minutes
I would like to see some pics of Katana right out of mill untouched to see the anatomy. would really be nice to not have to hand finish as much.
It is the same as all zirconia, similar to ef mill with emax. Milling at the larger size allows more detail, to a point. Sorry, I don’t have any pics at the moment
Ivoclar is going to have to step up and come out with an emax multi or zircad ht. My ratio of emax to katana flipped this week. Not sure that will be the case every week, or if I'm just playing with a new toy. Someone needs to come up with a way to make these things faster too. This oven has been out for over two years, so the wow factor of fast zirc shouldn't be such a big deal anymore.
I thought this was a perfect case for it. Margin was entirely on cementum and dentin with a thin chamfer/shoulder margin. Probably should have gone one shade down, but I didn't have it in stock.
Finally did a few posterior cases with Katana and I have a thought on shade selection. As Mike mentioned above, the material is definitely translucent enough for a darker tooth to show through.
It is also translucent enough for the cement to make a difference. Mike is using RMGI ( fairly opaque white cement) to lute the katana units in and recommends matching the vita shade exactly. I am using speedcem in an A something shade and after three or four units last week, I think going one shade brighter per noritake’s suggestion in the above slide might be better with a tooth colored cement. I believe the recommended Panavia product is tooth colored as well. The units I cemented seemed to be just a bit low in value, kind of like the old pressed ceramics tended to be, or how a full contour crown in emax ht might be expected to turn out. I think the RMGI might act almost like an opaquer and bounce more light back through the restoration.
I’m going to try Katana this week. What RMGI’s are you all using? I have the older MCXL so the Zico is takes even longer to produce. Almost does not work for one day dentistry.
Great post Mike. Thanks for showing the difference. I did my first one yesterday and it looked great and fit wonderfully even on a tough prep.
At the Katana symposium they recommended you bond the crowns with Panavia or a similar resin cement to add strength especially with the STML. They gave us an article from Compendium Vol 37. No 9 "How to Bond Zirocnia: the APC Concept" by Markus Blatz for anyone who wants to read up on it. I have not done a lot of research on this personally but just to throw it out there... Mike would know more about the details on this but they made a point about not using a RMGI. Would you speak to that Mike? You seem to read just about every article published... how you have the time is still a mystery but it sure benefits us all ;)
On 4/11/2018 at 10:52 am, Kristine Aadland said...Great post Mike. Thanks for showing the difference. I did my first one yesterday and it looked great and fit wonderfully even on a tough prep.
At the Katana symposium they recommended you bond the crowns with Panavia or a similar resin cement to add strength especially with the STML. They gave us an article from Compendium Vol 37. No 9 "How to Bond Zirocnia: the APC Concept" by Markus Blatz for anyone who wants to read up on it. I have not done a lot of research on this personally but just to throw it out there... Mike would know more about the details on this but they made a point about not using a RMGI. Would you speak to that Mike? You seem to read just about every article published... how you have the time is still a mystery but it sure benefits us all ;)
Kris-
I am on my own on this and do not have any real evidence. If you want to be sure, you will follow Kuraray's recommendation to bond the Katana blocks in. I am basing my decision on anecdotal evidence of cementing e.max over the years. I have had very good luck with the proper preparation. I perform occlusal reduction on Katana similar to e.max and feel comfortable cementing them conventionally with those parameters. Since Katana is a bit stronger than e.max CAD (or even if you want to say similar), my experience tells me that likely they will be successful cemented. I want to be clear though that I don't have any long term evidence to prove that. You all will have to do what you are comfortable with. Also, be aware that Katana is not as strong as conventional high strength zirconia. You have to have proper thickness.
Mike, that logic makes sense. I also have had great success cementing emax in the posterior when prepared properly. Out of curiosity, what RMGI are you using? And are you preparing the Katana in any way other than just cleaning and air drying it?
I did my first Katana crown on Monday and I was really impressed. I was able to place a great looking and fitting crown on a 1st molar that would have normally received an E-max due to being visible in the patients smile. I had just over 1mm of occlusal thickness and so just cemented it. I've been using Calibra Universal for some time now and it has worked very well.
Brian
I find the Panavia V protocol so easy and quick (it takes if I count the waiting time on a regular cement to react not really longer) that I just follow the most recent scientific recommendations and feel safe. And that I do for all kinds of zirconia.
I also tried to sinter 3 units at the same time, 2 came out good , one still opaquish. Try to sinter one at a time. I am not sure how bridges will come out, of course we do not have blocks yet. Gregory
It is an unshaded multilyer block fairly white. You have to infiltate for shade
That is what I have found out about NW I am going to mill one and sinter for upper second molar soon and I will post a photo
Just a heads up, if you screw up and put in the wrong size block (selected 14 but put in a 12), this is the warning that you get.
that error was driving me insane Dan... I was messaging with Germany that there was a problem... i realized I was the problem :)
Is it relatively normal for the blocks to be somewhat different in shade polished versus glazing? This is an A3 block. The left is hand polished and the right is glazed and fired.
On 4/17/2018 at 11:38 am, Ray Morse said...Is it relatively normal for the blocks to be somewhat different in shade polished versus glazing? This is an A3 block. The left is hand polished and the right is glazed and fired.
Yes... polishing will be lower value
Thanks for the side by side comparison. This begs the question, which one is more accurate to A3? What a substantial difference!
On 4/17/2018 at 11:38 am, Ray Morse said...Is it relatively normal for the blocks to be somewhat different in shade polished versus glazing? This is an A3 block. The left is hand polished and the right is glazed and fired.
What happened to your buccal margin of the polished crown?
On 4/17/2018 at 11:38 am, Ray Morse said...Is it relatively normal for the blocks to be somewhat different in shade polished versus glazing? This is an A3 block. The left is hand polished and the right is glazed and fired.
Ray, can you take that picture with an A3 shade tab?
Brian
Did that accidentally yesterday on a katana, assistant sent it through finished but I found out after mill it was done, of course had to remill. I have now reminded everyone to check the Katana block size
