Comparative radiation doses in dental radiography. WAH LEE, B.5., Rockville, Md. Oral. Surg. 37:962-8 (1974) Dental radiographs were taken with x-ray techniques of 44 to 91 kVp and cone lengths of 4,8, and 16 inches at two filtrations and at a constant entrance-skin field size in a tissueequivalent head phantom. Exposure times were adjusted for each x-ray technique to yield radiographs of similar diagnostic qualities. When a radiograph was taken with a low-kilovoltage, short-cone technique instead of a high-kilovoltage, long-cone technique, the integral dose in the irradiated tissue increased 8.2 times. The skin dose increased 7.5 times; the mandibular dose,3.1 times; the thyroid dose, 4.3 times; and the eye dose, 10 times. Very little significant alteration in doses to the phantom was observed when the total filtration in the 70 to 90 kVp range was changed from 1.5 to 2.5 mm. of aluminum. The dose values reported in this study are in 62

close agreement with the findings reported reported by Alcox and Jameson in a recent study under clinical conditions. L. R. Manson-Hing

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