Blackening of unprotected dental X‐ray films due to scattered radiation

Abstract

Sewerin I, Stoltze K: Blackening of unprotected dental X-ray films due to scattered radiation. ScandJ Dent Res 1988; 96: 161-6.Abstract -Unexposed films awaiting exposure as well as exposed films awaiting processing are subjected to scattered radiation if kept unprotected in the dental X-ray clinic. The purpose of the present study was to analyze the influence of varions storing principles, film speed, and distance from X-ray source tipon the degree of film blackening. Test films were subjected to scattered radiation from 150 exposures. Maximum additional blackening (0.27 D) was recorded for type E films not protected by lead foil at the shortest distance studied (55 cm). As a distance of 200 cm blackening was reduced to 0.02 D and could be futlier reduced by utilizing the inherent protective effect of tbe lead foil. It is concluded that if dental X-ray films not in use are kept at a distance of 200 cm from the X-ray source and protected by lead foil additional blackening due to scattered radiation is negligible and further protective precautions are unnecessary.

Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

“…Dental X-ray films are sandwiched in a plastic packet which contains the film itself, a black paper envelope which protects the film and a lead foil. This foil has different functions: (i) reduce the backscattered radiation in the human tissues [7,8] which degrades the image contrast and; (ii) reduce the primary and secondary (scattered) radiation dose on the salivary glands (patient radiation protection) [9]. Another lead foil function, which we raised here, is its use as an "image intensifier" (ecran).…”

Lead foil wrapping of the plastic scintillators for the gamma ray detection: optical reflector or spectrum intensifier?

“…This problem is partly similar to that of X-ray films in conventional imaging; the low thickness of the film reduces its X-ray absorption efficiency. In the case of these films, two lead foils are placed on both sides of the film to intensify the output image and also to reduce the effect of the backscattered photons from the object [8][9][10].…”