An assessment of the relative safety of dental x-ray equipment.

Concern among patients, often prompted by medical practitioners, regarding the harmful effects of radiation caused by dental x-ray procedures, has caused several patients of the dental school of the University of Pretoria to refuse dental radiographic procedures. Buch and Fensham in a previous article demonstrated that radiation doses to the eyes and thyroid resulting from a single pantomogram constituted less than 10% of that which would be imparted by a transatlantic flight in terms of added natural background radiation. The authors in this study investigated doses to the same organs resulting from a full-mouth periapical series first using films and then digital imaging. Doses to the uterus resulting from these same examinations as well as from a pantomogram were also determined both with and without the use of a lead apron. Doses to the eye from a full-mouth examination using film compared favourably with those for a panoramic examination, but were much reduced when digital imaging techniques were employed. Doses to the uterus were small (equivalent to half a day of background radiation) for both a full-mouth examination using digital imaging, as well as for a pantomogram. However, from the results it would appear that there is little difference in the dose of scatter radiation to the uterus from a full-mouth examination whether or not a lead apron is used. The use of a lead apron for a pantomogram significantly reduces the dose to the uterus.