Ivoclar Vivadent Vectris - Manual (Page 10)

10
Q U E S T I O N S
&
A N S W E R S
What material should be used to prepare an
impression that can be poured several times?
A silicone, polyether or similar material should be used for
impression taking as these materials provide an optimum
reproduction of detail. Additionally, the impressions taken
with these materials can be poured several times.
Hydrocolloid and alginate materials are unsuitable and
cannot be poured more than once.
What if the impression needs to be poured only
once or if it has been damaged during the first
pouring?
In this case, a duplicating impression (Double Take) is
prepared with the help of the master model or a multi-
section model. Then, the impression is poured with type IV
stone.
Can the model be cut up into detachable
segments before preparing the duplicating
impression?
Ideally, the model is divided up into detachable segments
after the duplicating impression has been prepared. Block
out the cut lines with wax, if you have divided up the model
first.
MODEL
PREP
ARA
TION
Can you wear latex gloves to process the matrix
material?
Latex gloves inhibit the curing of Transil. Therefore, Transil
should not come into direct or indirect contact with latex
gloves. For the processing of Transil, use vinyl gloves.
Does Transil need to be used each and every
time?
It is advisable to use Transil each time, as this material clearly
improves the adaptation of the Vectris fibres to the model,
provides a homogenous layer thickness and facilitates the
working procedure. It is imperative to use Transil for the
fabrication of bridges and inlay-retained bridges. The only
cases that do not require the use of Transil are dies of
posterior crowns with a flat occlusal preparation.
Can Transil be applied intraorally?
Transil must not be applied intraorally.
What characteristics should the exterior surface
of the Transil matrix exhibit?
The exterior surface should be as smooth as possible so that
it does not hinder the passage of light. Use the
accompanying Vectris foil to smooth the exterior surface
(prior to polymerization) or use a scalpel (after polymeriza-
tion). Light becomes scattered on rough, uneven surfaces
and, consequently, fails to penetrate the matrix effectively.
How thick should the Transil matrix be?
The matrix should be 3 to 6 mm thick. If it is thinner than
that, it may become deformed. If the matrix is thicker, the
Vectris material may not polymerize and cure properly.
Is it necessary to apply a Vectris foil if Transil is
used?
It is imperative to apply a Vectris foil only if you do not use
Transil. If you use Transil, you may employ the foil to smooth
the exterior surface of the silicone matrix while it is still soft.
How long is the working time of Transil?
The working time is approximately 1 minute.
SILICONE
MA
TRIX
What is the minimum thickness for Vectris
frameworks?
Single crowns and bridge abutments must exhibit a mini-
mum framework thickness of at least 0.3. to 0.4 mm. The
surfaces should not be ground after the vacuum-forming
process has been completed.
What are the dimensions of the connector area
in bridges and inlay-retained bridges?
The connector area between the bridge abutment and
pontic should measure at least 3 x 3 mm in bridges and
inlay-retained bridges.
What are the appropriate dimensions for the
pontic/abutment contact area (occlusal and
palatal/lingual) when the pontic is placed?
The pontic/abutment contact area should measure at least
3 x 3 mm and should be at least 0.3 mm thick. It is
advisable to shape the pontic/abutment contact area in such
a way that it supports the cusps. The pontic should reach at
least 4 mm into the tooth for inlay-retained bridges.
What are the minimum dimensions of the inlay
box for inlay-retained bridges?
The proximal aspect of the box should be no less than
3.5 mm and the occlusal depth no less than 2.5 mm.
Observe the preparation guidelines.
FRAMEWORK
DESIGN