Effects of developer exhaustion on the sensitometric properties of four dental films

Objectives: To examine the effects of exhaustion of five different processi ng solutions on the sensitometric properties of four dental X-ray films: Ek taspeed Plus and Ultra-speed (Kodak Eastman Co. Rochester, USA) and new and previous Dentus M2 (Agfa-Gevaert, Mortsel, Belgium). Methods: An aluminum stepwedge was used to construct characteristic curves for the four films. All films were processed manually using three sets of c hemicals for manual processing: Agfa (Heraeus Kulzer, Dormagen, Germany), K odak (Kodak-Pathe, Paris, France) and Demat (Viscopac, Athens, Greece) and two sets for automatic processing: Durr XR and Periomat (Durr Dental, Bieti gheim-Bissingen, Germany). Film speed and gradient were evaluated until the chemicals were completely exhausted. An analysis of variance was performed separately for each set of chemicals for manual and automatic processing. Results: Ektaspeed Plus was the fastest film in the manual processing solut ions. The new Dentus M2 and Ektaspeed Plus films had similar speed using th e chemicals for automatic processing. Ultra-speed had the lowest speed in a ll solutions, but it had the greatest consistency. Exhaustion of the develo per caused a comparable decrease in speed of Ektaspeed Plus and the two Den tus M2 films. In fresh chemistry Agfa was the strongest manual processing s olution, but it had the highest exhaustion rate. The Durr XR chemical was s tronger than Periomat over the whole test period. Conclusions: The combination of film and processing solution is an importan t factor for achieving constant sensitometric properties. Ektaspeed Plus an d the new Dentus M2 film should be used in dental practice, as they require lower exposure and have equivalent or superior properties compared with Ul tra-speed.