Program including abstracts as pdf available here

OP 94
Title
INFLuENCE OF THE REMNANT bEAM ON OCCuPATIONAL DOSE IN INTRAORAL
RADIOGRAPHy
Authors
E. bERKHOuT 1
Affiliations
1 ACTA - Department of Oral Radiology, Amsterdam, NETHERLANDS
Body
Objectives: In The Netherlands every dental clinic must have a risk analysis of occupational
effective dose. However, a variety in methods of calculating the occupational dose is currently
used. Therefore the aim of the study was to assess occupational dose values from intraoral
radiography from the remnant beam and subsequently to develop a Dutch standard in occupational
dose calculations from intraoral radiography.
Methods: The Unfors Xi survey detector was used to measure radiation dose in the remnant
beam. The detector was placed on the other site of the phantom’s and patient’s head in line
with the X-ray tube at 1,50 meter distance. H*(10) was measured as an indicator for effective
dose. The data were compared with the non-attenuated primary beam and measurements of
the secondary radiation around the patient.
As dependent variables exposure time, the radiographic detector, beam collimation, mA and kV
were taken into account.
Results: The occupational dose in the remnant beam was significantly higher than in other
directions from the head of the patient. However, at the same time the measured doses were
significantly lower than the dose of the non-attenuated primary beam, especially behind the
patient (frontal X-rays).
Conclusion: Compared to earlier studies the occupational dose is relatively higher in the
remnant beam. This can be explained by the study setup. We mimicked the clinical situation
which means that in intraoral radiography the mouth of the patient often is partly open. These
data can be used for a Dutch norm for dose risk assessment in dental clinics.
Keywords
radiometry, radiation dosage, radiography
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