Table 2
Fission Track Autoradiography Procedure
used on two
teeth samples
from rhe
Marshall Islands
bescription of teeth:
Step
Dehydration
Infiltration
Embedding
no ID
Tooth A was an intact incisor
Tooth B was a molar with very little of the roots attached
Comments
Description
2 to 3 changes
ethanol
in absolute
placed in unpolymerize
methyl methacrylate +
IZ (by weight) of catalyst,
benzoyl peroxide for 2 days
replacement of above by
methyl methacrylate +
accelerator (25:1 by volume)
To minimize outgassing when teeth
are being irradiated and to permit
the polymer to infiltrate the teeth
full infiltration of teeth is more
difficult than of bone
The accelerator causes
the polymeri
-zation of the methyl methacrylate
through an exothermic
reaction
Curing
allowed the sample to solidi- Better curing can be done by using
a pressure chamber (e.g. 250 Lb/in
fy in a vacuum dessicator
and 50 °c)
overnight
Sectioning
use of carborundum saw
to remove parts of glass
mold
‘Ten sections ranging from
356 un Co
L816 um in
thick-
ness were obtained from
The cured material stuck to the.
glass mold.
Such should not have
occured if a mold releaser is
used.
Thinnest section obtained of
encapsulated teeth had been 250 yim,
according to the instruction manual
the two teeth samples with
a macrotome 2? precision
saw( 100 mm diameter diamond
blade, water cooled)
Preparation
for irradiafion
Each section was sandwiched
between lexan foils (250 um
tlric’ ,
&5 cm diameter) &
Wrapping oyAl foil is supposed
to provide OFact between teeth
and Lexan
5 pairs from cach teeth
stacked one after the other
and wrapped in pure Al foil
[rradiation
10+ at /em® see neutron flux
ratio is desired
A low n
prevent g 245B — fission and
for 2 hes at the Medical
Research Reactor which has
a thermal to Last neutron
Ambient
ratio of about 33.
Lemperature in the capsule
Control
is preater
diateq batch
5
than
50%
The
TaL(n., &) 24
reaction
teeth were inaccessible
Control lexan
at the time.
was not included in the irrathis
time( plain
to