الفهرس 
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Abstract
In this study we investigated the effect of:
1. Finish line design
2. Different types of waxes
3. Time of investing
On the accuracy of the vertical marginal gap and the internal surface
adaptation of full coverage metallic crown.
We used two metal dies made by milling machine having two different
finish line, one of the metal die have bevel finish line and the other
chamfer finish line.
100 wax patterns were made on the two metallic dies using different
types of waxes of different physical properties; we use hard, medium
and soft type. The used waxes were different in the melting
temperature, softening temperature, hardness and casting shrinkage.
The wax pattern were invested using two different time, were 50 of
them invested immediately and the other 50 invested after 24 hours.
After casting was done the metal crowns were examined using the
stereomicroscope to measure the vertical marginal gap distance then
crowns were sectioned longitudinally and again were examined under
stereomicroscope to detect how these factors control the accuracy of
the full coverage metallic crown at the marginResults showed that bevel finish line with the medium type of wax
when invested immediately gave less vertical marginal gap, while the
use of soft-hard wax gave better internal surface adaptation however
the type of finish line design.
. and there internal
surface adaptation.