As zirconia’s popularity continues to increase, it is becoming more and more difficult to navigate the ever expanding variety of products on the market. It seems that every time one turns around a new type of zirconia emerges with stellar promises of just how great it is.
Many of these new products are in what I like to call the “We did it for you” arena of shaded and layered zirconias. These types of products are surprisingly, at least in my opinion, gaining in popularity. I truly believe that confusion surrounding the proper use of coloring liquids along with huge variety of products on the market has caused people to throw their hands up in despair and run to what seems like a much simpler approach with these shaded products. While I do understand this, these materials bring a slew of other challenges, including large inventory requirements, shade segregation requirements, and nesting/milling challenges.
Not to mention being stuck with someone else’s interpretation of shade and the inability to customize shade or effects without excessive staining...which is another issue in itself!
The truth is, the coloring process for white zirconia is quite fast, accurate, predictable and most importantly easily understood. There are a lot of advantages with this approach including the ability to easily create custom color, add chromatized areas where needed, and vary the amount of incisal along with its translucency and value as needed. Creating proper incisal blending on longer bridges is another obvious benefit.
An unexpected benefit of this is the ability to eliminate or extensively limit the amount of stain required to achieve proper esthetics. As everyone knows, stain wears off and is temporary at best. It can also cause very unsightly results if the doctor grinds where the stain has been applied, creating what we sometimes call an “Optical or Doughnut Hole” in the restoration.
While I would certainly never argue that very nice results can be achieved with pre-shaded and layered products, I believe their limitations and challenges far outweigh their benefits. While beyond the scope of this blog, I must state that no matter which type of zirconia you prefer to use, the importance of finishing these materials in the green state can NOT be over stated. It is extremely important to avoid grinding on sintered zirconia AS MUCH AS POSSIBLE. The damage this can cause might....no, will...have dramatic negative effects on its long term strength!