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Acrylic troubleshooting guide
T
he latest book in the series “Dental Knowledge” from
Heraeus Kulzer, entitled Denture Teeth and Acrylics:
materials, processing, tips and tricks provides important knowledge about manufacturing, characterisation,
repair and care of dentures. The first part of the book
examines materials and processes. A key focus is on PMMAbased components of denture acrylics and innovative fillers in
artificial teeth as well as acrylic processing procedures in dental
manufacturers and the laboratory environment.
Furthermore the book includes the physical and chemical
properties of teeth and denture base material as well as the prerequisites for biocompatibility and long duration of use for denture
teeth. The practical section of the book includes the technical
Figure 1. Powder
and liquid
component of
the cold-curing
polymer PalaXpress
(Heraeus Kulzer).
procedure for producing dentures, from the first step of taking an
impression, through to the set up and gingival models and even
up to individual characterisation.
In addition, there are helpful tips and information regarding
denture care, repair and relining. The acrylic troubleshooting
guide at the end of the book explains the possible causes for
bubble formation, discolouration, cracks and several other issues
by giving valuable tips on how to avoiding these issues.
An extract from the acrylic troubleshooting guide appears below.
For a copy of Denture Teeth and Acrylics: materials, processing,
tips and tricks, contact Anne-Marie Maniura at Heraeus Dental
by email at [email protected].
3.6 Gap - tilting denture
Problem
Possible causes
Solutions
n Excessive application of separator
n Apply two thin layers of separator to the
plaster model (e.g. Heraeus Kulzer Aislar)
n Excessive polymerisation pressure
n Set pressure at 2 bar
n Pressure pot opened during
n Observe polymerisation time in the
the polymerisation phase pressure pot
n Deformation due to thermal damage n Do not polymerise cold-cured polymers
of cold-cured polymers at temperatures above 55°C / 131°F
If a gap remains between the denture base and
n Excessively fast cooling and opening n Cool down slowly - deflask denture at
the model, a poorly fitting, tilting denture can later
of flask lukewarm temperature at the most
cause bruising in the patient’s mouth and reduced
n Substantial deviation from the
n Mix acrylic as per directions for use
functionality
of the denture. For a precise fit,
specified mixing ratio
technicians
need to exercise great care throughout
the
entire manufacturing process, from the model
through
to the polished, finished denture.
Pala® Mondial
®
Pala
Mondial
Proven
function that
Proven
function
that
caters for
all demands.
caters for all demands.
n Intensive evaporation during cleaning n Clean with toothbrush and toothpaste
n Excessive contact pressure during
n Reduce contact pressure and
polishing (temperature) monitor temperature
3.8 Poor bonding between artificial teeth and denture base
Problem
Possible causes
Solutions
n Failure to roughen acrylic teeth
n Roughen teeth with a coarse diamond
or by sandblasting (50 μm)
n Silicone coat around the denture
teeth (release of silicone oil)
n Use a pure plaster investment
n Failure to wet acrylic teeth with
n Apply bonding agent to the roughened
bonding agent surfaces and allow to penetrate as per
the directions for 1; repeat process
n Excessive delay between the
n Process within the recommended,
application of bonding agent and time according to the directions
further processing for use for the bonding agent
n Wax or separator residue on the
n Do not evaporate wax residue, but boil
Teeth
can break off the denture base for various
mechanical
and chemical reasons. Appropriate
denture teeth out with clear, boiling water; rinse
pre-treatment
by the technician ensures reliable
separator residue off the denture teeth
bonding
between the teeth and the denture base.
with bonding agent
52 eLABORATE
March/April 2015
Flexibility in all areas of removable Prosthetics.
Pala Mondial provides increased flexibility with its large selection of mould designs.
Flexibility
in all areas of removable Prosthetics.
It also guarantees you a consistency in colour, mould and function.
Pala Mondial provides increased flexibility with its large selection of mould designs.
Fast and accurate set-up.
It also guarantees you a consistency in colour, mould and function.
Precisely defined centric, means they are simple to set-up.
Fast and accurate set-up.
Supremely accurate function without time consuming spot grinding.
Precisely defined centric, means they are simple to set-up.
Nanopearl technology guarantees high abrasion resistance and durability.
Supremely accurate function without time consuming spot grinding.
Life-like and vivid surface finish.
Nanopearl technology guarantees high abrasion resistance and durability.
Widened tooth base with increased volume, aid papillae contouring, eliminating both
Life-like and vivid surface finish.
dark recesses and vertical edges.
Widened tooth base with increased volume, aid papillae contouring, eliminating both
dark recesses and vertical edges.
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Giving a hand to oral health.
Giving a hand to oral health.
Pala Teeth are available from Gunz Dental, Durodent and Stradent
www.heraeus-kulzer.com