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QUARTER 3 | 2014 | CERECDOCTORS.COM | 31
strength and less wear to the opposing
teeth. They also provide superior absorp-
tion of masticatory forces. This class of
materials includes Lava Ultimate from
3MESPE and Enamic by Vita.
Vita Enamic is the first dental hybrid
ceramic with a dual network structure.
In this material, the ceramic network or
matrixisreinforcedbyapolymernetwork
with each network penetrating the other
to create a true hybrid material (Fig. 1).
In addition to exceptional elasticity, this
hybrid ceramic also exhibits excellent
adhesive strength after bonding.
CASE STUDY
A 65-year-old male presented with
missing teeth #3, #30 and #31. After
offering several options, the decision
was made to restore the edentulous
3
5
4
2
Fig. 2: Choosing teeth for restoring
Fig. 3: Crowns designed
Fig. 4: Abutment designed
Fig. 5: Crowns milled
Fig. 6: Characterization kit
spaces with dental implants. Four
months after placement of three single
implants, the case was ready to restore.
The Sirona TiBase kits and scan posts
were ordered in advance. The patient
was appointed for a 40-minute visit
to obtain the digital impressions with
the CEREC AC (Fig. 2). At this visit, the
healing caps were removed and the first
scan was of the gingiva. Gingiva mask
upper and lower folders were completed.
Next, all three scan posts and scan
bodies were inserted intraorally, and the
next two scans were taken of the upper
and lower arches. Finally, the buccal
bite scanwas taken. All healing capswere
replaced and the patient was dismissed.
The designwork in the software is rela-
tively simple. In4.2, all three crownswere
proposed simultaneously. The crowns
6
are initially designed full contour, with
the same goals of proper position, form,
occlusion and interproximal contacts, as
with traditional crowns (Fig. 3). Once the
crowns are designed, the next few steps
are unique to implant crown design. It is
important in the design to create proper
emergence profile, as well as closing
all gingival embrasures. With the
designs complete, the crowns are
then split into custom abutment
and crown (veneering structure). The
abutments were designed with attention
given to proper margin position rela-
tive to the gingiva as well as allowing for
proper material thickness (Fig. 4).
The three abutments were milled out
of Sirona’s inCoris zirconia mesoblocks.
Because the zirconiamust be sintered ina
sintering furnace, the task was delegated