THE EFFECTIVE ATOMIC NUMBER OF THE TEETH
1976 Volume 16 Issue 2 Pages 63-72
Details
1976 Volume 16 Issue 2 Pages 63-72
The effective atomic number of the teeth was estimated by calculation and roentgenphotometry.
In this calculation the data about the composition of the teeth was obtained from the papers by Zipkin, Lazzari, Brudevold, Leichester, Long, Trautz, Weidmann and Eastoe.
And a few corrections of the data were made in order to estimate the living composition of the teeth.
In roentgen-photometry, for the purpose of obtaining the linear attenuation coefficient of the teeth, step wedges of teeth were made by a diamond-cutter, and were placed on a film together with a step wedge of aluminium.
Roentgenograms of those step wedges were taken at kilovoltages of 41 and the film densities measured by a micro photometer were converted into attenuation curves of film exposure
The linear attenuation coefficients of the teeth were determined comparing with the attenuation curve by aluminium. The density of the teeth was measured, too, and Allen's formula was adopted to obtain the effective atomic number.
The calculated and experimental results were as follows:
(1) The effective atomic number of enamel was 15.3±0.3 in calculation and 15.6±0.8 in experiment.
(2) The effective atomic number of dentine was 13.4±0.8 in calculation and 13.7±0.8 in experiment.
