OCCLUSION BLOCKS - BMC Dentists 2011

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Record block or bite block
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Clinical
1- Examination
of the mouth.
CLINICAL
1 . Examination and Diagnosis .
2 . Preliminary Impression .
Stock Trays
Alginate Impression
Upper
Lower
LABORATORY
3 . Pouring the Impression .

2- Preliminary
impression making
*Pouring of impression to
obtain the study cast.
*Construction of special
(custom) trays
3 -Final impression.

*Boxing and pouring of
the final impression
*Construction of
recording bases and
occlusion rims

4-Recording of jaw
relationships and
selection of artificial
teeth.
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
It is a combination of a base material, which accurately fits the cast
(trial denture base ) and an arch shaped material occupying the
space of the patient’s previous dentition (occlusion rim).
It is therefore composed of
a trial denture base &
an occlusion rim
trial denture base
occlusion rim
They help in
1- Supporting the lips and cheeks to restore the
contour of extraoral landmarks.
2-The orientation of the occlusal plane.
3- Determining the vertical dimension.
4-Recording the centric and eccentric jaw relations.
5- Selecting the size and position of the artificial
teeth by the aid of the following markings :
a- Midline
b-High lip line
c- Canine line
“Part of the occlusion block that rests on the supporting structures and
carries the occlusion rim. “
trial denture base
Requirements:
They should :
1- fit the cast accurately.
2-rigid and strong to withstand the biting force.
3-be dimensionally stable.
4-stable inside the patient’s mouth.
5 smooth and clean to avoid patient’s discomfort.
6-be of proper thickness (2mm on the palate & less on the alveolar crest).
7-be easily and quickly constructed.
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Types
Temporary
Permanent
1- Shellac
2- Autopolymerizing and
light cured acrylic resin
3- Vacuum formed vinyl
or polystyrene
4- Baseplate wax
5- Swaged tin
1- metallic
gold alloys
cobalt chromium alloys
2- non-metallic
heat cured acrylic resin
• Temporary trial denture bases
1- Shellac base plate :
It is commonly used because of its cost. It is adapted on the
cast either by dry or moist heat.
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Temporary trial denture bases
2- acrylic resin
a-Autopolymerising
It is either mixed and adapted on the cast or it is sprinkled on
It offers rigidity, close adaptation and can withstand heat and
pressure without deformation.
b- Light cured resin :
it.

Temporary trial denture bases
3-Baseplate wax
It is easily adapted and can be thinned to gain space to set the teeth.
However, it lacks dimensional stability since it cannot withstand
biting pressure and body temperature.

Temporary trial denture bases
4- Swaged tin :
Three layers of swaged tin adapted on a metal die of the master cast
and cemented together by a thin film of hard wax. It is accurate,
dimensionally stable at mouth temperature and provides uniform
thickness of the final denture.

Temporary trial denture bases
5- Vacuum formed vinyl :
Preformed sheets adapted by vacuum. It provides a fast,
rigid and accurate record bases. However, it needs expensive
equipments and is difficult to trim.

Permanent trial denture bases
1- Heat cured acrylic resin

Permanent trial denture bases
2-Metal (gold, cobalt chromium and chromium
nickel alloys)
“ They are occluding surfaces fabricated on temporary or final
denture bases to record the maxillomandibular relation and
to arrange teeth. They simulate the space occupied by the
natural teeth and the related structures.”
Material of construction :
1- Wax : most commonly used.
2- Modeling plastic
Wax occlusion rim
3- Plaster and pumice
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Method of construction of wax rims
1- Ready made rims: by a device called occlusion rim former .
2- Freehand molded rims: wax rolled and shaped to the arch
form .
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