How do I design this?

[user name]

Im using 3Shape...I received a case for a version of a Maryland. Ill be replacing upper left lateral, and rather than cover the linguals with an etched retainer, the Doctor prepped a pretty good 'box' just above the cingulum. He was wanting it to be done in e.max, but I said no. I want to design a Zr frame that will be completely wrapped in porcelain; strength from the Zr but can still etch the inlays.
I don't appear to be able to select just a pontic and pull the design into the preps; it tells me 'no' because the pontic isn't part of a bridge. I suppose I could design the inlays, but then they'll be designed to fit the preps, and I want them 'out' of fit by enough that the porcelain has room. What do I do?

 

[2thm8kr]

Not a 3shape user, so use caution.... Start your work order as a three unit bridge. Increase your die spacer to make room for porcelain/glaze that you will use on the intaglio side for etching later. Or ask Cool Hand.

 

[user name]

I like the cement space idea, but I don't think I can start as a bridge scan without sectioning the model...I was hoping to keep it solid.

Luke....?

 

[Saluki]

In order form try using un sectioned model if using solid models

 

[CoolHandLuke]

it could be quite important how exactly the little bar is placed and in which direction it faces.

in any case this is a simple old trick.

don't mark it as Inlay/Onlay, it will freak out. mark it standard coping and pontic and connector.

when you scan the case scan the solid as the prep model. pour yourself a set of single dies for the wings. use the singles when the scanner wants a die.

in the design phase mark the margin on the edges of the box on the lingual side of the edges. so not ON the margin, but sort of overhanging out of the box by a hair.

edit: i seem to have misunderstood. snipped away the bad advice.

alright this is pretty simple. you fill in the box with wax until the box contours the tooth. cut into the wax a little before the edges and not deep enough to fill the box. essentially wax in the box until it is smaller. now around the margin of the box dig a trench.

place the margin as previously advised, just overhanging the original box margin (and your trench) by a slight amount. remove all die spacer and blockout. do not enable them at all.

proceed with design. ensure pontic seats on gingiva, ensure connector is adequate. when you seat the finished milled product you will have to ensure the fit; this is the reason for adding the trench. this trench when filled in with zirconia will allow you to place the bridge on the dies with a wet material such as fresh wax or such, and when you pull the bridge off again you will see if the wet material overhangs the trench, and in so doing verify your fits.

if it fits, add your porcelain. best of luck.

if it were me, i'd just add some glaze to a full contour zirc wing, give it a light sandblast, and this will be etchable. for that design i'd do nothing different but add a slight bit more die spacer. however this seems to work best on full maryland wings and not tiny keyhole slot boxes.

message me in the AM if you want to teamviewer.

 

[Marcusthegladiator CDT]

Im using 3Shape...I received a case for a version of a Maryland. Ill be replacing upper left lateral, and rather than cover the linguals with an etched retainer, the Doctor prepped a pretty good 'box' just above the cingulum. He was wanting it to be done in e.max, but I said no. I want to design a Zr frame that will be completely wrapped in porcelain; strength from the Zr but can still etch the inlays.
I don't appear to be able to select just a pontic and pull the design into the preps; it tells me 'no' because the pontic isn't part of a bridge. I suppose I could design the inlays, but then they'll be designed to fit the preps, and I want them 'out' of fit by enough that the porcelain has room. What do I do?

It's been a while since I touched 3 shape. I remember selecting my abutments for wings as copings. Then decreasing my margin offsets to zero. And the angle to 180 or something like that. I didn't have a problem designing. But if it wasn't for sum3d allowing me to orientate that thing any damn way I pleased when I nested, it wouldn't have been possible. You can etch the wings. I spray them with zirluster hi temp spray glaze and fire at 990c. Then build the porcelain, finish, and etch the intaglio of the wings. Had lots of success. My doc read studies about an increased debonding rate when using two wings. So we use one. And to this day, success. Good luck.

 

[user name]

before your post Luke, I tried to scan the solid model but it says 'only for temporaries'. I didn't get anywhere with that.

if I pour dies to scan separate from the solid, they will have trouble meshing the scans and will keep giving an error message, wont it? If that's not an issue, then...

Why set cement to zero? Im thinking that would make a completely tight fit? Why not increase the cement a lot?

 

[CoolHandLuke]

i edited post, because i realize i derped pretty hard.

 

[CoolHandLuke]

now, in order to scan a solid you dont do anything different in the order form. mark it sectioned and leave it sectioned. you trick the software by giving it an un-cut model at the time of scan. then as you proceed to die scan you shouldnt have trouble so long as the mark for the die is placed for example not on the margin of the wing but on the sulcus or just above it.

don't trim these dies just cut them.

 

[CoolHandLuke]

the reason i had you make a smaller box and then make a margin way outside of it is so that when you go to process the case you can seat the thing on the model instead of having it float in mid air. once the porcelain is added under the wings you can zip off that larger wing.

 

[AltreX]

If it will get very annoying send me scanned jaw model STL file and a scanned wax up file. I can make you design in half hour and send you back 3D pdf for you to validate . (y)
PM me for contacts

 

[KentPWalton]

i edited post, because i realize i derped pretty hard.

 

[user name]

Thanks everyone.

 

[Kaypan]

I usually just select temporary on prepared model. Set up the pontic where you want it(if you want space for porcelain just design a "smaller-anatomic" pontic),use morphing tool or wax tool to extend the pontic out to your box. Then in the last design step, use the cut to gingiva tool to get your space between model and maryland bridge.

 

[KentPWalton]

Do it as a bridge. It's simple, used to do it all the time.

Two abutments where the preps are and a pontic. Will be

glad to show you if you want to teamviewer it.

 

[user name]

Thanks again everyone. Im sure Ill have no trouble designing it as a 3 unit, but my original idea was:
If I can place a pontic and just stretch my design into the inlays to press porcelain around, Id be looking at a 31 dollar frame, but if I design using margins on the abutments, then Im doing a 93 dollar frame.

Maybe that sounds screwy, but that's just how my outsource partner rolls.

 

[KentPWalton]

Ahhh...I got ya. 3 unit trying to turn it into a 1 unit. Sounds like a Dr. talking there!

 

[user name]

I cant spend it if I don't make it.

 

[CoolHandLuke]

if you want to do it as a 1 unit its even simpler. scan the solid model using the Temporaries. place the mark for the unit on the pontic area.

add and sculpt it and morph it from literally the pontic up.

but use the uncut, temporary scan. this will not ask you for a die.

a word of caution though because if you end up modifying the gingiva or smoothing the area on the design near that base then your design doesnt have anywhere to sit to check fits.

 

[user name]

Ive never done temps either, so I guess I should spend more time learning.

I just realized my boots are on the wrong feet...youd think my mom would've noticed that when she tied my laces.