Fun With Single Central's

[paulg100]

Ok theres so much great info and help on this site that i thought id take the time to contribute a small case that might be of interest.

To complete single centrals to a high standard is a complete PITA as many of you will know.

This is a case i finished with my brother (the Dentist) a little while back.

The Core was fabricated with an inlab system in Emax CAD and layered with Emax Ceram using a two stage ceramic build,

then a seperate stain and seperate glaze fire.

While im not a big fan of external staining, getting close matches with these cases is almost impossible without this, unless you are super super talented.

By paulg100 at 2010-06-18

Pre-op situation with old crown in need of replacement.


By paulg100 at 2010-06-18

First the sintered core in an LT Block, after some fitting down (damn inlab!) and contouring under medium magnification.


By paulg100 at 2010-06-18

First build using dentine, amixture of opal enamel, enamel, mamelon and essesence/dentine mix for the incisal third translucent band.


By paulg100 at 2010-06-18

Second build using different translucents and opal enamels.

By paulg100 at 2010-06-18

Bisque bake on model after refinement with fine diamonds.


By paulg100 at 2010-06-18

Finished case on model after stain, glaze, buff on lave and rubber wheel.


By paulg100 at 2010-06-18

Finished crown in situ.


By paulg100 at 2010-06-18

Close up in situ. Value and translucency is still slightly off but damn close.

Now i would love to say this was the first attemp at this crown, but then i would be lying.. this was the third attempt!.

This case was part of my ongoing efforts for BACD accreditation, but due the slight difference in value and translucency i did not submit (looks more evident on full face photo).

The more i use emax and get a feel for the diffrent opacities and ceramic powders the more i love this stuff. With some more time,
hopefully i can get matches like this and actually make some money from these cases

 

[Al.]

Damn nice work!

I have a cool tip I just picked up by accident Ill share here when I get freed up a bit.

 

[TheLabGuy]

Beautiful end result........
I particularly like the halo's and that little tiny/minute white mark....matched it....kudo's.
The texture appears a little off, but that could be the reflection from the camera lighting. Did you use a cad/cam die stone, or do you spray before scanning?

Thanks for sharing........

 

[DMC]

Uber Nice!

You and Al make Mother Nature look bad.

 

[paulg100]

Thanks for the kind comments

Yeah the texture was off. Still working hard at replicating micro texture accuratly as it can really make or break a case.

Its particularly difficult with emax ceram due to the low fusing nature and the close proximity of temps, you can easily loose fine detail over multiple firings.

Photoshop can be realy handy for mapping surface texture though, ill post something really cool on this in antoher case.

I do use scannable stone, fuji rock optiscan works best for me, but i only use this for multi unit cases generally. On smaller stuff i use scan spray.

 

[Al.]

You may already know this.
Set your contrast to the max and it really seperates the dentin from the enamel and it shows the translucent zones and levels.




Looks like #8 has really reflective high value dentin on the gin 1/3.
Cant duplicate that with regular dentin porc, mabey a 50/50 mix of dentin and MM Light? Mabey if it was 100% LT core material at the gin?

 

[paulg100]

great stuff Al, hadnt picked up on that yet! thats gonna be real handy.

You can see that the translucency extends further up the incisal and there is a real challenge, making a prep/coping look like its translucent. Im getting at lot of this with bleech shades,

I think the secret lies in a combination of staning the coping with blue, dentine/neutral trans mix and using the impulse (EE15 it think? a purple colour) and mixing with enamel to form an absorbtion mass, its tricky for sure.

Its either that or you make the coping short and leave unsupported porcelain which is not good.

Yeah i think your idea of using MM mix would replicate that high chroma dentine real well but good luck on getting the mix right on the first run

I spend so much time faffing with mixes in the lab to replicate these cases, its what kills the profit.

Im guessing your playing with photoshop, have you messed about with the filters yet? if not your gonna love the next case i have to post popcorn

 

[dmonwaxa]

Cool tip Al, I've been using it for years. Also if you have a photo with the shade tab included in the shot, convert it to greyscale (B&W) you can see any differences in value between the shade tab and natural teeth. PaulG, I and so many others feel your pain when doing single centrals. Way too time consuming.

 

[cassidy]

Final photo

Hi, I just wondered if you have a photo showing your finshed work? I would like to see how it looks at the bottom when you're done.
Thanks
Cassidy

 

[Toast]

Great tip Al, will definatly try this soon.

 

[TheLabGuy]

I wonder how dark the prep was........
Appears from the original picture that this was a non-precious crown from the tattoo'd tissue and the black oxides it appears to be leaching into the dentin/enamel. I wouldn't be surprised that the color at the cervical that Al pointed out isn't the LT trying to cover up this blackened prep.