The influence of storage conditions on film characteristics of Ektaspeed plus and Ultra-speed films

Background. Dental professionals were reluctant to accept Ektaspeed (Eastma n Kodak Co.) intraoral film despite its X-radiation dose-sparing advantages for patients. One reason may have been Ektaspeed film's known sensitivity to long-term storage as compared with that of Ultra-speed film (Eastman Kod ak Co.). In 1995, Kodak replaced Ektaspeed with Ektaspeed Plus, claiming it had better resolution and higher stability than Ektaspeed, as well as equa l exposure radiation. The authors compared film response to storage conditi on and time for Ultra-speed and Ektaspeed Plus films. Methods. The authors stored 10 boxes of newly produced Ultra-speed and Ekta speed Plus film in five locations. They conducted 23 image trials over a 26 -month period, exposing each film with an aluminum step-wedge under control led conditions. After processing the film, they measured density to calcula te the film's base + fog and contrast index values. Results, The authors found significant differences in film type (P = .0002) , processing status (P < .0001), storage location (P < .0001) and month of storage (P < .0001). They also found a film-type-by-location interaction (P < .0001) but did not find a film-type-by-processing interaction (P = .3271 ). Regression lines suggested that the optical density of base + fog levels rose more steeply for Ultra-speed film than they did for Ektaspeed Plus fi lm. A significant association of decreasing contrast with increasing months of storage was seen with Ultra-speed film (P < .0001). There was a small i ncrease in base + fog levels resulting from the use of used solutions over the course of the study. Conclusions, Ektaspeed Plus film compared favorably with Ultra-speed film u nder all conditions. Clinical Implications, The authors recommend the use of Ektaspeed Plus film for intraoral imaging, as its performance is comparable to that of Ultra-s peed film while requiring half the X-radiation exposure to patients. Clinic ians must ensure that the correct safelights and processing solutions are u sed before switching to the new film.