Thanks to the ceramic engineers at 3M we now have a material, zirconia, strong enough for most applications. The origin of this market began with Lava, a CAD CAM fabricated framework material with very limited inductions and a very steep cost of entry.
Many lab owners paid in the $250K range to bring manufacturing in-house. Although very successful, Lava did have several challenges. The CAD design was antiquated and posed many problems to designing proper frame design. The mill, being 4 axis, also limited manufacturing of some geometries. The block’s initial form enabled only single units, followed by larger blocks that eventually enabled eight unit cases. There were additional problems with baking ceramics to zirconia that have been well documented. Chipping and delimitation were all too common. More recently, through developments made at Glidewell laboratories, full contour zirconia has become increasingly popular. In part, this is due to dependability, as there are no layered ceramics and thus no chipping or delimitation.
Full contour monolithic comes with low cost of manufacturing, continued esthetic improvements and increased indications. The original Bruxzir material from Glidewell was milled from a 98mm disk, which enabled any size restoration.
The disk was white, resulting in the need to dip the milled restoration into coloring liquids before sintering. More recently many companies have added colorants to the disk to eliminate the dipping process. This has proven to be a more consistent manufacturing process with fewer shade problems, but the restorations are very monochromatic and more opaque than natural dentition.
Today, developments include several new disks that have multiple shades pressed into each disk. For instance, CAP Multi FZ has a cervical, body and enamel shade with a blended zone between each layer. As the latest advancement we now have a monolithic multi-shaded material that more closely resembles natural dentition. Priced similar to other quality disks, the esthetic barrier of zirconia is rapidly becoming a thing of the past.
In the not too distant future we will have zirconia materials that will be far more translucent. Expected by year end, the new class of zirconia materials will likely become the go-to product for many dentists. This newest class zirconia material will not be as strong as the materials of today (1100 MPa) but offer a 50% increase in strength (at 600 MPa) over lithium disilicate (360-400 MPa). It is anticipated this new super high translucent material will be available in pre shaded discs for predictability and ease of use.
It’s truly amazing how far we have moved the needle on zirconia in such a short time.
For more info on CAP Multi FZ please visit: http://cap-us.com/products/cap-multi-fz-fz-2/
Thanks for reading.
Bob Cohen, CDT