Back in April, we attended a course for RealGUIDE™ with Zimvie. The course focused on design workflow for a split bar case—an all-on-x fixed denture supported by a titanium bar. Thanks to the expertise and help of course directors Darren Emert and Casey Kahn, we were able to absorb a lot of information in a short amount of time.
RealGUIDE™ is not only a CAD software. It’s a collection of cloud-based programs for every step of the restorative process from implant planning and surgical guides to definitive design. What’s more, doctors and technicians using RealGUIDE™ can collaborate and communicate through each phase.
We were so pleased with the results of the course that we decided to take our design home and process it.
When manufacturing an all-on-x case with a digital workflow, first we print the upper and lower models in our Carbon 3D printer and place analogs in the implant sites. We don’t have to worry about any distortions in the printed model because Carbon’s printing tech is extremely accurate.
Next, we mill the titanium bar in our Imes Icore 350i™ mill. Cases like this underscore the benefit of having such a capable machine in-house. In little time, we have a precisely milled version of our design, and after some quick processing we can seat it on the printed model to verify a passive fit.
Then, we mill the zirconia arch in our Roland 52 DCi™ mill, which cuts an enlarged version of our design out of a puck of compressed zirconium dioxide powder. The result is a white arch that once baked (sintered) will shrink to our precise size and change color to the shade of zirconia we picked—generally, one of the sixteen Vita Classic shades or the bleach shades.
The milling job takes three to four hours, and then I can get to the fun part. Using a no.11 blade and a green state zirconia finishing kit from Wagner, I deepen the incisal embrasures, proximal contacts and the free gingival area, and I add some character and texture to the gingival portion.
It’s important that I take my time with this step. It is a vital part of the process that can easily be overlooked but makes all the difference between clearly false teeth and a lifelike restoration. The mill can only go so far in creating the depth necessary for these areas, and it takes a human touch to push the zirconia towards our standard of biomimetics.
Once the arch is fully crafted, I like to use some pre-sinter coloring to enhance the incisal character, chroma in the gingival third, and to add some color to the gingival area. Then, the arch is ready to go in the sintering oven overnight.
The next day, we have a beautiful zirconia arch ready to finalize. The real moment of truth comes when we place the titanium bar in the arch. There are a lot of variables at play when milling and sintering a large case that can distort the product, but when the proper protocol is followed the bar fits the arch like a dream.
I like to complete the esthetic phase in three bakes—one for color, one for glaze, and one for gingival texture. Using MIYO™ ceramic paste colors, I carefully create the illusion of a translucent incisal third which transitions to a higher value middle third and then to higher chroma leading into the gingiva.
With a variety of colors, I then create the illusion of translucent tissue in the gingival section, with higher pink saturation in the more vascular areas like the papillae and the alveolar mucosa, and lower pink saturation above each tooth to mimic the alveolar bone. I can also use fine streaks of different colors here to mimic veins.
Once those colors are baked, and after fully glazing the arch, I use MYIO Structure™ on the gingiva to complete the esthetic transformation. Structure not only adds color to what I’ve already placed, but with it I can create a texture mirroring natural tissue—complete with distinct papillae, labial frenum and stippling. The result after the final bake is a natural smile ready to be delivered.
Every esthetic restoration, from a single central to a full arch, is a challenging and humbling opportunity to return not only a patient’s function but also their smile. As always, we thank you for your continued partnership in that process.
