Here are the pictures from my first emax crown.
If you want to know a little about emax crowns then have a look at this video from Mark Oborn.
I confess myself to be a Mark Oborn Fan and you can read more about his lab on this blog.
I’ve put all the pictures of my case into a little video as I’m finding it an easier way to present a group of slides. However it’s hard to put all my comments on the slides so watch the video once, read the extra info below and if you need to watch again. Also here is a link to the high def version: emax crown
open source video, online video platform, video solutionThe patient was unhappy with the PFM crown and clinically I was pretty unhappy with the margins. The tooth had an adequate root filling. I offered the patient a private replacement. I reprepped and sent the photos with the impressions. It was the first time I’d used the lab (not SBO btw) so I wrote an introduction, described the case and the shade I also drew this on the lab ticket
Here is a quote from the email
“Please find attached a series of photos for the emax crown case I have sent to your lab.
They show the preop smile, ICP and open views. A view of the smile with a shade tab c2 and my prep pictures and temporary crowns which are for reference only, I’m not sure you will need them. I’ve sent you a few pictures in different positions with different flash positions to help show you the reflection patterns better.
As for the shade I think the tooth is c2 at the incisal edge but blends down into a a shade closer to c1 near the apex. It’s an unusual transition.
2 weeks later I fitted the crown.
Now if we critique the crown I think the fit was excellent around the margins the incisal level and shape is good. However I find the shade to be too monochrome. Where is my transition to C1 cervically. The patient was really happy with the crown though and it was a huge improvement. Also to be honest I couldn’t guarantee a new crown would be any better as single teeth can be hard to match and I coudn’t see what more information I could give the lab. So I fitted it and my patient was made up.
I’m a bit disappointed though. The lab is a pretty well know one in the north east and I paid for premium service about £120. I think they have just put shade c2 on this crown and I suspect I won’t use them again. It depends how they respond to my email critiquing the work.
Lets not just blame the lab though. What could I have done better?
Well you can see from the prep pictures that the cervical third of the labial service is just underprepared and I kick myself for not checking and adjusting this a little. With more space the technician might have had room to improve the aesthetics although emax does allow minimal reduction.
Also the gingiva at the apex is slightly receded after the temporary crown. This should drop as the soft tissues settle but I should have cut a negative ledge in the temporary to prevent this at fit.
So what are your thoughts?
Good, bad or average. Don’t get me wrong I’m pretty happy with the case overall and that crown should last for many years doing a far better job than it’s predecessor. I just hate relying on dental labs that don’t listen to me. I can’t see any evidence of a second shade in that crown and I wonder why. The problem is I just don’t know enough a bout making emax crowns to have an open discussion with the lab.
Next year I want to spend 1 day a week working in a dental lab as an apprentice. I want to get to know the team, learn the techniques, shadow and be able to do the lab work myself if I needed to. I’m excited to do this and I think it will prove a very wise investment in time. Think about all those expensive masters courses where you pay a fortune to learn how to do lab work. Wouldn’t it be wiser to work with a lab for free, just give your time and pay with cases you send?
You may ask why a lab would do this? and I guess the wrong ones wouldn’t. But I think some would think that this is a unique opportunity to really work with a dentist, get a good understanding and lets be honest have his business for the rest of his career.
I’m well up for it and I see know reason why you shouldn’t bang on some doors and try to get a similar opportunity. Time can be as much an investment as money and expensive courses are not always the key to further development. a business partnership might be though. Just a thought for you…
Hope everyone had a nice easter
All the best
Chris
#1 by Jonathan Moulding at April 5th, 2010
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Hi Chris,
Good presentation especially liked the video/ embedded powerpoint presentation.
I agree the crown may be a bit monochromatic, also I don’t think the lab have done the greatest job in matching the incisal edge wear pattern.
Single teeth are extremely difficult, were you able to send the patient to the lab for shade taking?Also if you felt the lab didn’t follow your clear instructions, maybe it should of gone back for a remake, especially because the shade graduation was requested and not suppplied.
In the end though was the patient pleased? Because that is the most important thing.
I hope you see these comments as constructive, its very brave to put your work up in the net to be critiqued like this.
Regards Jon
#2 by ChrisO'C at April 5th, 2010
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Hey Jon,
Thanks I value and appreciate your comment and of course I take constructively.
I like to think I”m my own harshest critic and I know I try my best so what can you do? I write a dental blog and therefore there is an obligation to be honest or else it becomes worthless, that means posting the best cases and some that are not.
The tooth does actually look better in the mouth than you might think and the patient was very happy with it which is why I cemented it though I did come back and wonder if I’d done the right thing. I certainly would not have fitted it if he wasn’t.
I haven’t found a local lab close who I can send patients for shade taking and I wanted to send the work a little further than usual becasue this lab has a good reputation. I thought with my shade photos and diagram I had the bases covered. Maybe next time!
I think the important thing is to always do your best and keep trying to improve
Cheers
#3 by Andrew caldeira at April 6th, 2010
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Hey chris, I’ve had a similar situation if doing a veneer on a single central incisor. I explained to the patient that we can take photos for the lab to decide on shade however the best result would be for technician to see them in person. I start by explaining to the patient that since they are spending a premium amount that it is worth seeing the technician. We offer a call out fee for the technician to visit the surgery but the patient will always decide on visiting the lab itself (Nottingham) as it is considerably cheaper for someone to get a train from Rotherham to Nottingham or even drive.
Then end result is that the patient decides with the technician on the whole matching process. 1. The patient feels involved. And 2. Removes the onus from your point of view as technically you weren’t involved in that process.
I’ve had very good results that way round and the patient is extremely happy as they gave input too.
#4 by Alex at April 8th, 2010
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I imagine that your patient is very pleased with the crown. I agree the shade isn’t quite what you asked for but i think it’s the form that doesn’t quite match. The incisal form of the last PFM toned in better with the 21 and i don’t know if it’s the light/flash but the surface texture around the incisal edge doesn’t mimic the tecture of the 21 that well, though i can’t really see fantastically from the photo.
Did you send a picture without the ring flash, just lit from one side? I seem to remember that that shows texture better. Also i think a black and white photo with a shade tab can be helpful for assessing brightness (can’t remember if it’s hue, chroma, saturation etc)
Alex
#5 by Pete Buchan at April 14th, 2010
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From the photos… and thats always diffcult… I think you got a C2 crown…. and that is what the photo with the shade tab shows… but your lab ticket asks for a”C1 at the apex”. So has the lab tech followed the picture and not follwed the lab ticket?
Would it have been better to have a pic with the main body shade C1 so as to prevent confusion with the tech?
To me from the photos the base shade looks more like a A2-A3.
Surface chararcterisation could be better.
Solution to all of this is go with Cerec and then you get to controll all these factors. (And realise how complex/difficult it is for the tech that does not get to see the patient)
You will learn loads from time spent in the lab with the techs – those guys are great with their hands.
Pete
#6 by Jason at April 21st, 2010
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I use emax as onlays and veneers. when I am doing a full crown, which is fairly uncommon these days, i use PFM or zirconia based crown. my reasoning is tooth structure conservation thus reduce biological cost. Emax is a fantastic material but it cannot be milled/pressed as thin as zirconia or metal. So in non-aesthetic critical areas such as palatal of the upper ant or lingual of the lower posterior the tooth reduction still has to be a bit thicker to make space for emax. Emax is stronger than the overlying ceramic on PFM or zirconia crowns but it is something that can be overcome with good coping design that supports the ceramic. I think it is a fair compromise for conserving tooth structure. Especially palatal of upper anteriors. That being said, I try and avoid crowns and bond ceramic in whereever possible. A philosophy that will get some older dentists really worked up.
#7 by Toronto Dentist Blog at June 29th, 2010
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Hi Chris,
I’m doing a lot of Emax. From second bicuspids and forward that’s my first choice for a few years now. Beautiful margins.
Try getting your lab to do some cutback and layering instead of just casting a monochrome colored block. That will improve the aesthetics tremendously.
Joe Bulger – Toronto Dentist
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