Dentaltown May 2017 - 51

match either the adjacent preparation or
adjacent tooth structure. (Details about
this procedure appear later in this article.)
Another advantage of these copings can
be found in large-span bridge work with the
presence of a pier abutment. A pier abutment,
also known as an intermediate abutment, is
a natural tooth between terminal abutments
that serves to support a fixed or removable
dental prosthesis. A typical example is when
the patient is missing the maxillary first
molar and maxillary first premolar on the
same side. The maxillary second premolar
is the pier abutment between the canine and
the second molar15 (Fig. 5). A pier abutment
requires a nonrigid connector if it's going to
be restored with a fixed prosthesis.17

Fig. 5

Disadvantages
Telescopic copings presented some
disadvantages that limited their uses to
specific clinical situations:
* Fabricating copings and superstructure
involves more complex laboratory and
clinical procedures, such as additional
casting and clinical remounting.
* Laboratory costs and treatment fees
are generally increased, and thus the
restorative treatment plan will have
a higher cost for the dentist to cover
these fees.
* In the past, the use of the conventional
telescopic prosthesis may not have
been recommended when there was
a high aesthetic demand, because the
copings were traditionally fabricated
from a gold or similar alloy.
* It may be difficult to place both the
gold collar of the coping and the
metal margin of the superstructure
subgingivally if a patient presents

with high lip line at
smile and thin, delicate
gingival tissue around
anterior abutment teeth.
This gingival tissue
biotype is more prone
to recession, possibly
caused by prosthodontic
Fig. 6
procedures such as
tooth preparation and impression
making16-20 (Fig. 6).

Advantage: lithium disilicate
Previous studies and articles have used
porcelain or zirconia copings to manage
the obvious disadvantages in aesthetic
cases.16,20,21 This article will demonstrate
the use of E.max (lithium disilicate, Ivoclar
Vivadent) copings and discuss its advantages
over traditional gold and zirconia copings.
Handling a dark preparation: Many
of us have had the aesthetic case of two or
more anterior aesthetic restorations where
one of the teeth has a dark preparation.
(Figs. 4 and 7). Typically, a dark preparation
is handled by using an opaque restorative
medium such as a porcelain fused to metal
or zirconia crown.

appear brighter than the adjacent natural
teeth. In the case of a cosmetic smile design
the restorations will all be of a higher value,
and the added opacity or brighter appearance
can result in an artificial appearance.
The solution is to fabricate an E.max
correction coping, which can be made of an
opaque ingot, to block out the underlying
dark preparation. The coping is then
externally stained to match the adjacent,
normal preparation (Fig. 8).

Fig. 8

Fig. 7

The issue becomes that the opaque
restorative materials tend to be slightly
higher in value and offer less natural fluorescence than adjacent natural teeth or
restorations. The treating practitioner is
typically forced to make one, both or all
restorations more opaque to compensate
for the dark preparation.
The result can be an aesthetic failure.
In the case where one or two teeth were
treated, these restorations will not match
the adjacent natural teeth in value and will

The telescopic crown can then be made
of the same ingot as the adjacent crown's.
This provides several benefits over gold or
zirconia copings. One, it allows the practitioner complete control of value by utilizing
warming (lower value) or brightening (higher
value) try in pastes and cements.
Secondly, considering that the coping is
being used as a block-out medium and not
being used as a stress-breaker, the coping
can be bonded to the tooth using a total-etch
technique (recommended because the coping
is typically less than 1.5 millimeters thick),
as well as the ability to bond the E.max
coping to the E.max crown. Lastly, the
telescopic crown allows practitioners to use
one cement for the entire case, rather than
multiple materials, as was recommended in
traditional coping cases.
dentaltown.com \\ MAY 2017

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