Jeffrey Caso One great feature of the 4.0 software is our ability to position the restoration within the block. In previous software versions we only had the ability to change the sprue location. This helped to keep the sprue away from the contact areas, but really that was all.
In the 4.0 software, we have expanded capabilities and the ability to move the sprue by rotating the restoration, as well as moving the entire restoration within the block both up and down and front-to-back as well as side-to-side. If we use these features properly we can soon see the many advantages they provide.
First, the mill tools are accessed through the side bar in the milling phase. Choosing “Sprue,” we can rotate the restoration around an axis – thereby moving the sprue away from the contact and placing it on a thick area, away from the margin which will decrease the likelihood of fracture during milling. This tool also allows for us to reset the sprue to the software’s default location.
Also accessed from this same menu is a “Move” tool. It has two options. Selecting “Position” allows us to move the restoration front-to-back and side-to-side. Selecting “Rotate” allows us to spin the restoration incrementally along a full circle, which rotates around the sprue.
So, what are the applications of these tools? Well, in one instance I was certain that I would need to send a very large implant crown to the lab. In previous software versions there was no way that it would fit in a block. In 4.0, I was able to move and rotate it enough to just get it to fit. This saved me a large lab fee and allowed me to turn this crown around in a very fast timeframe. In another instance, I was able to splint two lower incisors and position them in the block diagonally and avoid sending the case out.
For every case, I find myself moving the sprue to a thick line angle. That seems to be my favorite location and gives me a great mill.
I also was curious about how we could improve mill times by using the tools appropriately. I chose a very standard molar restoration and positioned it right at the end of the block, furthest from the sprue. My mill time was 5:30. I then moved it as close as possible to the sprue and the mill time was 7:06. That's more than a minute and a half longer. That may not seem like much, but factor in extra wear and tear on the mill and burs, and over time it can be significant.
So, spend a few seconds and tweak the mill position. Keep the restoration as far away from the sprue as possible and on a thick, non-contacting surface. Take advantage of all that 4.0 has to offer.
