الفهرس 
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Abstract
This study was to detect and evaluate gamma radiation emission for
prefabricated zirconia dental implant and customized zirconia implants made
from different zirconia blocks by CAD-CAM machines.
For this aim the prefabricated implant (ceraroot) was scanned using two
different CAD-CAM machines (Ceron and cerec 3), and three implant groups
were milled from three different types of zirconia blocks (cercon ht,vita yz
and zircad)
group I: Ceraroot implants. (Control group).
group II: Cercon ht zirconia implants.
group III: IPS e.max ZirCAD implants.
group IV: Vita inceram YZ for inlab implants.
The gamma radiation emission was measured through hyper pure
germanium detector to determine the amount of radioactive radionuclide.
The amount of uranium radioactive series (238U) ,thornium radioactive
series (232Th) and radioactive potassium (40K) was measured for each group.
Afterwards the amount of annual internal exposure dose was
calculated.
The results were:
1. The mean value of 238U radionuclide had the highest value in group III
(18.617 Bq/Kg), it showed significant difference when compared to the
other three groups.
2. The mean value of 232Th radionulide had the highest value in group II
(39.873 Bq/Kg) it showed significant difference when compared to group
I and group IV and no significant difference when compared to Group3. The mean value of 40K radionulide had the highest value in group III
(73.7901 Bq/Kg) it showed significant difference when compared to all
groups.
4. No significant difference between the annual internal exposure dose
between the four groups.