Original scientific paper
A Method to Evaluate and Compare Two Different Intraoral Radiographs of the Same Patient
D. Knezović Zlatarić
A. Čelebić
O. Milat
M. Papić
Abstract
Objective of this study was to determine the accuracy of the method of the clinical
intraoral densitometry, to compare differences in the calculation with or without subtraction
of the background adjacent soft-tissues from the stepwedge (SW) and to verify
which regression model best fitted the experimental data in order to express the measured
values in equivalents of SW thickness. Two intraoral radiographs, one after another,
were made for each of 6 patients. A copper SW (6 steps, thickness 0.05–0.3 mm)
was attached to each radiograph, trying to avoid the superimposition of the bony structures.
Films were processed and digitized. Grey levels were measured on each step of the
SW, on the background of the SW and on the same 3 randomly chosen regions of interest
(ROIs) on each digitized image. The measurement with and without the subtraction of
optical densities of the background around the SW from the optical densities of the SW
was performed. For the calculation of the SW thickness equivalents, the regression
analysis was performed by using different regression models. The best fitting regression
model was the 3rd degree polynomial. The results were more precise when using the subtraction
of the background overlapping the SW.
Keywords
Hrčak ID:
28313
URI
Publication date:
16.12.2002.
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