RADIATION DOSE IN DENTAL ROENTGENOGRAPH, WITH SPECIAL REFERENCE TO ENLARGEMENT DENTAL RADIOGRAPHY
Dosimetry was used to estimate the radiation dose received by dertal patients and dentists in dental clinics in Japan, and the results were compared with those obtained by an enlargement technique. The phantom of paraffin used for measuring exposure doses was based on a whole-body plaster of panis cast of a Japanese of medium size. The lungs in the phantom were made of cork with a specific gravity of 0.2, and three holes were constructed in the oral cavity, lower abdomen (ovary region), and testicular region for insertion of a dosimeter. Since in most dental clinics in Japan the x-ray apparatus is installed in the corner of the treatment room without any Pb protection, dose distribution of scattered x rays was also surveyed. Four types of x-ray units were used, and measurement was performed at distances 50 to 200 cm at levels of 50 and 100 cm from the floor. The gonads received a dose of about 0.5 to 3 mr per exposure in males, and 0.03 to 1 mr in females. Patients received radiation doses of 10 to l000 mr per exposure at the eye lens, 1500 mr on the nasal apex, and 500 mr on the thyroid region. Not less than 100 mr of radiation was distributed in the regions of the pharynx and cervical spine. For dentists holding the film in the patient's mouth, about 1 to 3 r were received per exposure. They also received whole-body irradiation of scattered rays of about 500 to 2000 mr/hr. Since in Japan, even at present, the dentist usually holds the fllm in the patient's mouth during radiography, and if he conducts dental radiography 10 times a day, he should receive 10 to 30 r on his hands a day, or 3000 to 9000 r a year. Furthermore, the dentist standing near the patient is exposed to scattered rays of about 1.4 mr per exposure. Therefore 11 exposures per day give the upper limit of irradiation dose according to maximum permissible dose. The long-cone method, it is suggested, is of value not only for making enlargement radiograms but also for diminishing the exposure dose of dentists since it prevents the production of scattered rays. (BBB)
- Research Organization:
- Nagoya Univ., Japan
- NSA Number:
- NSA-18-018097
- OSTI ID:
- 4032068
- Journal Information:
- Nagoya Journal of Medical Science (Japan), Vol. Vol: 24; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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