By: Pamela Hanneman CDT
We have so many options at our fingertips for implant restorations these days. From the abutment height and angle choice to the plethora of zirconia selection to top off that abutment. Now I know after my last blog you are all using OI Ti Bases because you learned how important the customisable height is in relation to retention and cementation surface.
I have been involved with testing and evaluating zirconia for many years now. I remember being utterly disappointed by the first generation’s esthetics or should I say lack thereof. I will need to confess, I was not exactly happy about this new material quickly gaining popularity in the dental laboratory industry. I’m sure I called it chaulk and stuck my nose in the air claiming I will never switch from layered PFM’s. The fact is, today I wouldn’t even consider a PFM as a restoration for myself or any other patient. Yes it’s absolutely amazing to carve anatomy into feldspathic porcelain. I miss that feeling. What I don’t miss is patching metal spots in the fossa because it was so easy to carve and even easier to go too far! I did become a master of patching metal spots as you can imagine.
When I look at what is available today, I find myself pretty impressed with the combinations of translucency and strength. The need to layer porcelain over zirconia is really reserved for custom shades or matching previously restored adjacent teeth in my humble opinion.
Screw retained crowns and custom abutments present some unique challenges depending on their placement in the mouth. Posterior restorations take the majority of the mastication forces and require an Mpa between 950 and 1200. The higher the Mpa, the stronger the zirconia. This leads to a slight compromise in translucency.
Some zirconia brands that I have worked with have proven to deliver both strength and esthetics in their newer offerings. Providing strength and a translucent gradient is the ideal solution.
NOPE! I do not get paid to promote them. I am simply a CDT that knows what she likes and shares with others. Below are 3 of my top picks based on real life results.
A secondary challenge can be when the restoration calls for super translucency and also the ability to mask the underlying substructure. This happens mostly in the anterior region where mastication forces are much less and it would be acceptable to use a lower Mpa zirconia for esthetics, but it will most likely not provide the ability to mask the metal substructure.
Solution #1 would be a hybrid abutment made with a stronger or more opaque zirconia with a final restoration completed in a super translucent zirconia.
Solution #2 A screw retained crown designed with a slight cutback. Milled with a higher Mpa zirconia, and a micro layer of zirconia on the facials. This approach gives you an easier way to achieve your goals of strength and esthetics without having to go through the lengthier first option.
If you are not getting the final esthetics you desire currently, I hope that the products and processes I have tested will also serve you well. Of course there is more that can impact the results such as proper sintering. I will be addressing this other very important topic in my blogs to come. Thank you for reading and I will be back soon.
You can always find me at [email protected] to help with any of your abutment and digital material questions.