Comparative dosimetry of dental cone beam computed tomography, panoramic radiography, and multislice computed tomography

The aim of this study was to compare the effective organ doses from cone beam computed tomography (CBCT), multislice computed tomography (MSCT), and panoramic radiography. The tissue-absorbed doses for the Kodak 9500 CBCT system, NewTom FP CBCT system, Morita Veraviewepocs panoramic X-ray device, and Somatom Sensation 16 MSCT system were calculated using thermoluminescent dosimeter chips placed at selected locations on a radiation analog dosimetry phantom. The tissue weighting factors recommended by the International Commission on Radiological Protection in 2007 were used to obtain effective doses. The effective doses from the CBCT systems were 118.65, 84.45, and 75.43 μSv for the Kodak 9500 large field of view (FOV), NewTom FP, and Kodak 9500 medium FOV, respectively. The effective doses were 11.37 μSv for the panoramic X-ray examination, 583.73 μSv for the MSCT ''Dental'' protocol, and 1983.89 μSv for the MSCT ''NeckThinSlice'' protocol. The doses from CBCT are not sufficiently low to allow its use as a routine imaging technique instead of panoramic radiography. The FOV size should be chosen carefully to prevent excessive exposure of the patient to radiation. The use of MSCT in dentistry is associated with much radiation and should be avoided in cases where CBCT is adequate for 3D evaluation. (author)