Sensitometric characteristics of D-, E- and F-speed dental radiographic films in manual and automatic processing

BACKGROUND AND AIM:The purpose of this study was to evaluatethe sensitometric characteristics of Ultraspeed,Ektaspeed Plus and Insight dental radiographic films using manual and automatic processing systems.METHODS:In this experimental invitro study, an aluminum step-wedge was used to construct characteristic curves forD-, E- and F-speed radiographic films (Kodak Eastman, Rochester, USA). All films were processed in Iranianprocessing solution (chemical industries Co., Iran, Tehran) both manually and automatically in a period of six days.Unexposed films of three types were processed manually andautomatically to determine base plus fog density. Speedand film contrast were measured according to International Standard Organization definition.RESULTS:There was significant difference in density obtained with the D-, E- and F-speed films in both manually andautomatically processing systems (P < 0.001). There was significant difference in density obtained with the Ultraspeed andinsight films. There was no significant difference in contrast obtained with the D-, E- and F-speed films in both manuallyand automatically processing systems (P = 0.255 , P = 0.260). There was significant difference in speed obtained with theD-, E- and F-speed films in both manually and automatically processing systems (P = 0.034, P = 0.040).CONCLUSIONS:The choice of processing system canaffect radiographic characteristics. The F-speed film processed inautomatic system has greater speed in comparison with manualprocessing system, and it provides a further reduction inradiation exposure without detriment to image quality.