الفهرس 
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Abstract
This study was conducted to assess the dimensional accuracy
of three different denture base materials namely (heat cured acrylic
resin, microwaved acrylic resin, and thermoplastic resin).
Nine identical horse shoe shaped custom made acrylic base
were constructed using a horse shoe shape custom made metallic
mold, with the following dimensions (width 12mm x thickness 3mm
x length 12cm). This mold was used for the fabrication of the
denture base samples.
Molten wax was poured in the mold space on a flat surface.
The surface of the wax was flattened with a hot instrument, and
acrylic teeth were arranged simulating the normal setting of teeth on
the denture base.
Four metal ball-bearings measuring 1mm in diameter were
placed on the occlusal surface of the maxillary second molar
bilaterally and in the maxillary first premolar area bilaterally.
The sites of placement of the metal ball bearing were prepared
prior to ball placement, utilizing number 1 round bur and the ballbearing
were
fixed
by
using
tooth
shade
self-cured
acrylic
resin,
so
as
the
ball
bearings
were
elevated
by
0.5mm
from
the
surface
its
placed
on.
A plaster index composed three parts middle portion , right
half and left half were made on the finished waxed up denture sample
, to aid in repositioning of teeth when duplicating the other two
waxed up dentures.
Nine identical sheets of acrylic teeth were utilized in the
construction of the nine replicas of the waxed up samples.
Each waxed up denture was measured using
stereomicroscope, these measurements are: antro-posterior reading
82 from the metal ball in the second molar to the metal ball in the first
premolar this was done bilaterally, and two oblique measurements
from metal balls in the second molar area and the other in the first
premolar area and two transverse diagonal readings from the first
molar to the first premolar. Then flasked in accordance to
instruments and technique of each denture base material.
The prepared samples were measured before processing, after
processing, after polishing and after water storage. After that
statistical analysis was performed.
.