[Dose measurements comparing conventional and digital panoramic radiography].
OBJECTIVE
The purpose of our study was to measure and compare patient exposure by direct digital and conventional panoramic radiography.


METHODS
Dose measurements were carried out on an anthropomorphic phantom, which was specially developed for dental radiography. Panoramic radiographs were taken with three different conventional devices (Orthopantomograph 10E, Orth Oralix FD, Siemens Orthophos) and two direct digital devices (Orthopantomograph 100 Digipan, Siemens Orthophos DS Ceph). The exposure conditions were according to clinical routine. The energy dose was measured at 28 places inside and on the surface of the phantom by using a set of 108 thermoluminescence detectors. Additionally, exposure time, tube voltage, central-beam dose, and dose-area products were measured. The effective doses were calculated on the basis of the absorbed doses.


RESULTS
In each case, the highest energy doses were recorded at the parotid gland, the mandibular angle, the submandibular gland, and the skin in the neck. Panoramic radiographs taken with the conventional units yielded in effective doses in the range of 16-21 microSv, the digital units caused 5 or 14 microSv.


CONCLUSIONS
In comparison with conventional techniques, patient exposure can be reduced by direct digital panoramic radiography. The extent of dose reduction depends on the device employed and is generally smaller than the dose reduction that can be achieved by digital imaging devices in intraoral radiography.
Visser
H
H
Abteilung Parodontologie, Georg-August-Universität Göttingen, Deutschland.
Hermann
K P
KP
Bredemeier
S
S
Köhler
B
B
D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D011862:Radiography, Panoramic / Q000295:instrumentation*; D013819:Thermoluminescent Dosimetry