According to FDA radiological health department...
The limited use of E or F-speed films compared with D-speed films is often due to misconceptions about price, clinical film quality, and processing. A comparison of one manufacturer's D-speed film to E-speed or F-speed film shows no significant clinical differences in quality between the films. Using E-speed or F-speed film provides a similar mean-correct diagnosis, comparable sensitometric properties (i.e. technical aspects of film imaging) and similar clarity of film compared to D-speed film. E-speed or F-speed film is processed without significant changes in processing practices to those that are used for D-speed film.
Regarding the price difference between E- or F-speed film and D-speed film, the related costs boil down to a matter of several cents increase per film from D to F! As listed by an internet on-line vendor of dental film, a package (usually containing 100 or 150 films) of F-speed film is only $4 more than for the same package of D-speed film. This amount averages to only pennies per film, with a one-third reduction in exposure to the patient.
Conclusion: The facts that E- and F-speed film products offer significant exposure reduction compared with D-speed film, cost approximately the same and offer comparable clinical benefits strongly support a change of practice for those facilities that continue to use slow-speed film products that contribute to patients' exposures which are greater than necessary. Ask your dentist or dental technician if they use the faster (E or F) speed film and tell them the reasons for your inquiry.
