Sameer Puri D.D.S. On a recent trip to the headquarters of Ivoclar in Lichtenstein, we had the opportunity to learn more about the upcoming emax abutment blocks. The abutment blocks are the same emax blocks that you currently use for onlays and crowns, however, they come with a pre-milled hole that allows them to be precision fit to a metal titanium base. This concept is currently being done with great success however the blocks that are used today are zirconia blocks.
These blocks are Meso Blocks as mentioned are only currently available in zirconia. Zirconia is a great material but it requires some difficulty in sintering as you need a special oven to fire the blocks. The blocks can be seen below. Once you fire the zirconia block, the software automatically creates the overlaying crown on top which can be then milled out of any material and cemented onto the zirconia base.
The challenge with zirconia for the general dentist is the sintering process. Currently sintering requires an expensive oven and at least 90 minutes (although Sirona has announced a sintering oven that will sinter zirconia in about 10 minutes - more on that in a future blog)
The natural solution would be to use a material that will allow the general dentist to eliminate the zirconia portion of the restoration. Enter the soon to be available emax abutment blocks. Instead of a block of zirconia with a hole, you will now have a block of emax with a hole. This hole is precision milled to fit precisely over the titanium base (Tibase). Ivoclar expects these blocks to be available with the next CEREC software release - sometime later this summer.
So at the Ivoclar tour, we received some instruction on how to properly sinter the abutment blocks. Follow the following tips to ensure proper processing of the material. First thing, you need a special firing pin. If you see the crude photo from my iPhone below, Ivoclar has made available a thin pin to support the abutment block while firing. Second and very critical is that you do not want the side of the abutment to touch the pin- you should have some object fix in place so that it acts as a buffer between the pin and the abutment. Finally- use the regular firing cycle- no short cycles for the abutments. This will ensure that the material converts completely and fully into the proper final parameters. We will have these blocks for you to use at the hands on programs in the near future. Stay tuned as we await the US launch of these blocks.
