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