DENTAL TEAM: Gyu Cho, CDT, 3D BioCAD Milling Center, Renton, WA and Dr. Ronald Bryant, Seattle
RESTORATIVE PROBLEM: The patient presented with severe occlusal wear on his natural teeth; the lower anterior teeth were also very crooked and discolored. The existing crowns also exhibited wear, tissue retraction, dark margins and uneven shades from one crown to the next. Teeth #5, #12 and #14 were missing, requiring implants.
TREATMENT PLAN: A full-mouth restoration with 28 units was proposed and had full compliance from the patient. The team opted to use gold-hue abutments to provide a very natural, warm appearance beneath the restorations—full contour 3D BioCAD zirconia for all the molars and 3D BioCAD zirconia copings with layered porcelain for all bicuspids and anterior units. 3D BioCAD was chosen because of the material's esthetics and translucency; the discs are manufactured using isostatically pressed Tosoh zirconia powder under high pressure from all directions, versus uniaxially-pressed zirconia powder which is pressed from only one direction. This provides a denser zirconia that eliminates any micro-voids in the material which can ultimately lead to failure; therefore, it's capable of being used for long-span bridges and other applications not possible with uniaxially-pressed discs.
FABRICATION PROCESS: The models were scanned with a 3Shape D800 benchtop scanner and milled on a Roland 5-axis milling unit in 3D BioCAD's in-house milling center. After the units were milled and sintered, Cho used Zirkonzahn's shade liquid to enhance the translucency and natural esthetics of the shade. He then used Ivoclar Vivadent e.max Ceram Glaze Paste to easily achieve a natural-looking glaze.