Pushing boundries with emax LS2

[paulg100]

Ok here is a case that is a bit out of the ordinairy and it would be nice to get some opinions from other experianced tooth nerds.

This is a case i am currently wokring on with my brother. The case needed sub copings due to the diverging prep angles so we decided to make these in zirconia.

By paulg100 at 2010-08-02

The necks were scalloped and stained to around B2 (the final case will be around B1) then glazed and polished with diamond paste.

Now what to do with the overlay. Due to the slightly increased thickness of the sub copings over gold we have less space so we are toying with the idea of trying this as EMAX pressed linked bridges/crowns.

The upper would be a 1 peice design with 1 pontic of the back of 14 and obviously a pontic on 22. On the lower two seperate linked bridges/crowns. The left one with a pontic off the back.

Now the main questions is would the upper fit in a 300g ring and what people think about the strength issues. I would plan to press this full contour with an incisal cut back on the anteriors.

The alternative is to use zirconia but due to the limited space i think i can get better esthetics with emax cut back technique.

Anyone have any thoughts?

 

[dmonwaxa]

think emax is cotraindicated in both situations. Now here is a crazy idea, since the copings you have now are telescopic in nature, and concerns are space limitations i imagine on the facial, why not cut back a window on the copings and then do 2 zr fmks 1for each arch; that would slip over the copings and solve for the cantelever issue at the same time? Radical enough?

 

[sixonice]

you have quite the case there! very complex. i would think doing the case in e.max may not be the best restorative option. honestly i really think any material choice you decide for this case will be difficult to guarantee 100% success. that upper arch i wouldn't think would fit in a 300 gram ring. that ring was designed for press-to-metal and press-to-zirconia.

 

[paulg100]

Well if i do zirconia then ill wax frame and copy scan so this will give me a chance to measure and weigh the frame. I guess ill be in a position to see 1. if it will fit 300g ring and 2 if the ingot weight needed is less than 2.8g which i think is the max a 300g will take.

im thinking i can make the cantilever connectors basically the whole length/width of the contact so i think strength wise that would hold.

if i go the zirconia route i can probably thin the anterior facials to .2 as they are linked, which should be strongth enough. The next challenge would be trying to mill a 10 unit bridge in an inlab MCXL. 1 chip and there goes a $150 block.

demon: nice idea. One of the aims of the sub copings was to seal the preps to allow for any minor marginal issues on the large upper frame. Cutting holes in the copings would comprise this to some degree. Not sure how that approach would effect the strength of the copings also. They are actually cemented in situ now so modifying the copings further is not an option now.

Well which ever way i go, ill document this with photos and post at a later date.