Sensitometric comparison of speed group E and F dental radiographic films

Objective: To evaluate the sensitometric characteristics of Insight (R), (E astman Kodak, Rochester, NY, USA) a new F-speed film, in fresh and depleted processing solutions and compare them with Ektaspeed Plus (R). Methods: Two sets each of Insight (IP) and Ektaspeed Plus (EP) films were e xposed to radiation levels ranging from 10.7 to 685.2 mu Gy. One set of fil ms was processed in fresh chemicals while the other set was processed in so lutions that had been used for S days to process over 500 radiographs. Unex posed films of both types were processed in both solutions to determine bas e-plus-fog density, Speed and contrast were measured according to ISO defin itions and at other levels of density. Results: IP was in speed group F as measured at optical density I above bas e-plus-fog when processed under both conditions. It was 25% faster than EP when both were processed in new solutions and 35% h faster in the old solut ions, permitting a 20-24% reduction in exposure time. The speeds of both fi lm types decreased when processed in used solutions, but the decrease was s maller for IP than for EP, Speeds at other density levels were greater for IP than EP. Contrast as defined by ISO, and over Other density ranges, was similar for both films. Conclusions: Insight is an F-speed film with a speed at least 25% greater t han Ektaspeed Plus. 1P is more resistant than Ektaspeed Plus to decreases i ll speed when processed in used chemicals. Contrast of IP and EP is compara ble over several density ranges.