36
|
cerecdoctors.com
|
quarter 4
|
2012
BL4, to increase the value
of the patient’s teeth (Fig.
3).
The waxed-up model
of the full upper arch was
digitally impressed using
the Biogeneric Copy mode. Because both
are equally effective, an alternative tech-
nique would have been to place a small
amount of Bisacryl into a matrix of the
wax-up and create a mock-up of the teeth
before scanning the mock-up directly for
use as the model copy.
To obtain an ideal digital impression
using CEREC technology, it was necessary
to trough the tissue around the preparation
(
Fig. 4) using a diode laser (Picasso Lite
Diode Laser, Dentsply). After the prepara-
tions were completed, they were scanned
into the computer with the wax-up (Fig.
5).
CEREC intraoral scans should be
complete, with all the necessary detail (i.e.,
any information required regarding adja-
cent teeth) to fabricate successful resto-
rations. Therefore, the digital full-arch
impression included an accurate image of
several teeth distal to the preparations to
ensure the CEREC was supplied with the
appropriate information required to either
stitch or superimpose the wax-up over the
preparation master model (Fig. 6). At this
point, an alginate impression was taken
as a try-in model to verify correct seating.
Due to the length of the appointment, the
patient was given a lunch break during
which the restorations were designed.
Removed from the CEREC MCXL
milling machine one at a time, the resto-
rations were tried-in on the model. All of
milling and produce strong, esthetic resto-
rations. Of the several materials available
for use with CAD/CAM technology, IPS
e.max Impulse lithium disilicate (Ivoclar
Vivadent, Amherst, NY) was the mate-
rial of choice for this case. IPS e.max CAD
Impulse lithium disilicate monolithic
glass ceramic is known for its exceptional
strength. The lithium disilicate blocks
boast a flexural strength of 360 MPa and
are manufactured to tolerate high perfor-
mance milling, as well as the antagonistic
forces of mastication.
8
Lithium disilicate
glass ceramic is a glassymatrix composedof
70
percent fine, needle-like crystals evenly
distributed during the crystalline phase.
9
Its
strength and construction make it perfect
for conservative restorations such as inlays,
onlays and, in this case, veneers.
9
IPS e.max
CAD Impulse is indicated for use in the
office or laboratory.
9
Versatile in its appli-
cations, its translucent nature also renders
it ideal for use in the anterior region due to
its resemblance to natural dentition.
10
The
availability of three translucencies (HT, LT,
MO), three brightness values (Value 1, 2, 3),
and two opalescent shades (Opal 1, 2), along
with powders, stains, and glazes — which
can be used to further develop the look of
natural dentition and life-life optical prop-
erties — allow the representation of a wide
spectrumof dental esthetics.
8
I present a recent case inwhich CEREC
technology helped transform a patient’s
smile and self-confidence in just one visit.
CASE PRESENTATION
Brent, a 50-year-old male, presented with
multifactorial breakdown caused by a
history of acid reflux and parafunction (Fig.
1).
His “patchwork” dentistry performed
over the years was also breaking down.
There was no noted temporomandibular
joint (TMJ) pathology, as it appeared that
any interferenceswerewornaway, allowing
his joints to seat properly. Although self-
consciousabouthissmileforyears,hisnewly
acquired dental-sales position required him
to speak in front of and engage in conversa-
tion with dentists on a daily basis. This was
5
6
8
Fig. 5: Once completed, the preparations
were scanned into the computer along
with the wax-up.
Fig. 6: The wax-up was superimposed over
the preparation master model.
Fig. 7: Articulating paste was used to
determine where the preparation was
binding and the proper adjustments made.
Fig. 8: The ceramist arrived to perform
minor cutback and layering in the office.
| | |
H o rw i t z
7
the catalyst for restorative treatment. With
the understanding that more treatment
was needed to attain optimum oral health,
restoring his self-confidence with a new
smile was of first order.
One week prior to his scheduled
appointment, the patient underwent an
initial examinationwhich included taking
impressions for the creation of upper and
lower models, preoperative photographs,
a facial evaluation utilizing a facial
analyzer (Kois Dento-facial Analyzer,
Panadent), and a maximum intercuspa-
tion (MI) bite registration. Upon receiving
the records, the laboratory technician
performed a wax-up of teeth #5 through
#12
onto a model that would be scanned
into the CEREC utilizing the Biogeneric
Copy model (Fig. 2).
CLINICAL PROTOCOL
The day of the appointment, the patient
was anesthetized and the teeth were
isolated (Optragate, Ivoclar Vivadent).
The material of choice for this treatment
was IPS e.max Impulse V2 blocks, shade