Perceived quality of radiographic images after rapid processing of D- and F-speed direct-exposure intraoral x-ray films

Objective. We sought to compare the densitometric properties and perceived image quality of InSight (F-speed) and Ultra-Speed (D-speed) film radiographs processed with rapid chemistry. The effects of density, contrast, and film speed on perceived image quality were also studied. Study design. Images were made of a human cadaver phantom with exposures to achieve background densities approximating 1.5, 2.0, and 3.0. Films were processed in a radiographic darkroom by using Insta-Neg and Insta-Fix rapid chemistry as the manufacturer had recommended. Five endodontic residents independently analyzed images of varying density, speed, and contrast that were presented in a randomized manner. They were required to evaluate the perceived image quality of 5 specifically designated areas on the film, using a labeled photograph as a guide. These areas included root canal obturation, periodontal ligament space, dentinoenamel junction, and crestal bone height. In addition, they were also asked to assess the overall perceived image quality. Statistical analysis consisted of ordinal regression and 2-factor analysis of variance. Results. No statistically significant differences were proved between F- and D-speed radiographs within the same density group. Higher density and higher contrast resulted in a statistically significant positive impact (P < .01) on the ranking for all 5 subjective determinations. Observers preferred the films exposed to a background density of 3.0 over those of a lower density (P < .01). Conclusions. InSight (F-speed film) can be used with rapid chemistry to ensure less radiation exposure to patients than is necessary with D-speed film. The observers participating in this study preferred radiographs from the 3.0 background density group to those from the 2.0 and 1.5 density groups.