Complete and practical system of stainless steel cassettes and trays for the daily care and management of the dental and surgical instruments. The new cassettes are ideal to optimise the organization of instruments in the dental office. They allow to organizing different instrument sets, (depending from the different kind of operations) that will arrive chairside in sterile condition, ready to be used. The instruments can be placed again into the cassettes after their use, for disinfection, cleaning, sterilization and storage. This way the handling of contaminated instruments is strongly reduced and the risk of sharps injuries due to hand scrubbing, which is the major cause of cross contamination, is minimized. The instruments lie on two soft silicone rails, fixed on the bottom of the cassette and they are securely held, throughout the processing cycle, by a soft silicone retainer which is fixed on the cassette cover. The wide perforation of cassette’s bottom, cover and sides allow optimal disinfection, cleaning and sterilization and at the same time allow a very easy identification of the instruments inside.