Non-precious metal
comes of age
Chrome cobalt! A term like an impenetrable wall. Hard, cold, merciless. It is little wonder that non-precious
metal dental alloys do not have a good reputation – whether they are called chrome cobalt or non-precious
metal. The association is obvious, as something that is not precious cannot be good. However, non-precious
dental metal alloys are among the most orally resistant, durable dental materials. Amann Girrbach has now
introduced a procedure for processing chrome cobalt without water cooling in a benchtop milling machine.
As the material is in a pre-sintered, wax-like state it can be processed very easily. In this article the excep-
tional dental technician Knut Miller demonstrates how to get the best quality from “chrome-cobalt restora-
tions” with a little skill and knowledge of dental technology.
An article by Knut Miller, Vaduz/Liechtenstein
Knut Miller gives tips on how to produce the best results with Ceramill Sintron
K
nut Miller
is a dental technician
through and through. Someonewho
always wants to go one step further, who
isn’t easily satisfied and strives for perfec-
tion – in particular for natural aesthetics.
This has already been demonstrated in
his cult book “individualitas naturae den-
tis” in which he pays homage to the tooth
shapes and their characteristics. It can be
stated that this man understands his craft
and has integrated the theory of mor-
phology.
Knut Miller
now also works for
AmannGirrbach. At AmannGirrbach he
continually receives a very important
product development fromResearch and
Development to test the performance of
the new material or new technique and
saywhat he thinks has to be changed. One
of these innovations was and is Ceramill
Sintron; a CrCo sinter metal which is
processed while still in a soft state and is
therefore an interesting option for CAD/
CAM in-house fabrication of chrome
cobalt frameworks.
Knut Miller
and non-
precious metal? Yes, this also comes as a
surprise to you initially but after he had
used the material briefly and became fa-
miliar with its remarkable properties, it
became clear to him; chrome cobalt is his
new gold.
Using a demonstration case he describes
in the following article how he fabricates
dental restorations from simple CrCo.
The demonstration case
Tooth 21 was to be treated in the demon-
strationwith a fully veneered single porce-
lain crown. A partially veneered bridge
was also to be fabricated from 24 to 27
with the abutment teeth 24 and 27. The
two premolars were to be veneered with
porcelain – tooth 24 with a porcelain
shoulder in the proximal and vestibular
region – and teeth 26 and 27 were to
have a fully anatomical design. A full
crown for tooth 27 was the crowning glo-
ry in the truest sense of the word. A Ce-
ramill Sintron framework with a circum-
ferentially reduced cervical margin was
fabricated for tooth 21 to allow firing on
of a porcelain shoulder (Fig. 1).
The anatomy, morphology and function
can be fully customised and designed us-
ing the Ceramill Mind CAD software.
In this CADworking stage particular at-
tention should be paid to the milling re-
sult of the occlusal surfaces etc. It should
be noted, for example that the 0.6 mm
fine cutter canmill details more efficient-
ly, including the fissures. To ensure this
the fissures in the CAD software should
be opened slightly using the “Knife tip”
modelling tool (Fig. 2a and 2b). Even if
the manipulated details appear to be
slightly “excessively wide”, the fissures can
be more easily defined by the cutter in
this way – which optimises the milling
result.
In addition, when contouring a function-
al occlusal surface of a fully anatomical
restoration it should be noted that the
restorationmust always still be manually
reworked (e.g. polished). The proximal
and occlusal contacts should consequent-
ly be minimally over contoured to pre-
vent the contact points being lost or cre-
ating infraocclusion after mechanical
2
dent
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dialog
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VOLUME 14 06/2013 ©
D I G I TAL DENTAL TECHNOLOGY
dd
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