Seite 4 - Quintessenz Zahntechnik

STEP BY STEP
TRANSLUCENT ZIRCONIA
152 Quintessenz Zahntech 2013;39(2):150–160
A study model of the original situation (Fig 4) is available as a reference for the plan-
ned restoration. This model can be very easily incorporated in the Ceramill Mind CAD
software for virtual planning and design (AmannGirrbach). The basis of a study model
can then be individually modified in the CAD software (Fig 5) – if required or wished
– using the freeform tool. This type of information is very helpful as a guideline to grea-
tly shorten the time required for the design. The two anatomically reduced Ceramill
Zolid frameworks for the central incisors can be seen in Fig 6; the labioproximal sec-
tion was reduced for a ceramic shoulder, and the palatal guide surfaces were precisely
and dynamically reconstructed using the virtual Artex CR articulator (AmannGirrbach)
and “digital functional prosthetics” (DFP). This simple reconstruction of the functional
guide surfaces using the original situation considerably reduces the time required, and
the technician can concentrate fully on the shape and aesthetics when veneering. The
“DFP” contoured palatal guide surfaces, which in this case are not to be veneered using
build-up porcelain, must then only be finely polished to a high lustre using appropria-
te polishers (Ceramill Polish Lab Kit). It is very important, particularly with monolithic
zirconia restorations, to polish contact surfaces to a high lustre after grinding to avoid
abrasion on the opposing dentition or adjacent teeth.
During the design process of the abutments in the Ceramill Mind CAD software, the
margins of the emergence profile were placed so that the buccal margins were subgin-
gival (Fig 7) and the palatal margins were placed supragingivally (Fig 8).
The simultaneously designed Ceramill Zolid design abutments and bridge super-
structure – for teeth 13 and 16 – can then be nested, milled and, if desired, custom
Fig 5 The study model modified using the CAD freeform tool. Fig 4 The scanned study model.
Fig 6 The anatomically redu-
ced framework of teeth 11 and
21 with the dynamic guide
surfaces on the palatal.
Abutments in teeth 13,
16 and 17