What solution is used to remove unexposed silver halide crystals after exposing a dental X-ray film?

The fixer solution is specifically designed to remove unexposed silver halide crystals from dental X-ray film after the film has undergone the exposure process. When the film is exposed to radiation, the silver halide crystals that are not exposed to light remain on the film after exposure. The fixer solution contains chemicals that dissolve these unexposed crystals, allowing only the developed images to remain on the film.

In addition to removing unexposed crystals, the fixer also serves to stabilize the image, preventing it from further exposure to light and ensuring that it is safe to handle and will not degrade over time. This process is essential for producing a clear and permanent dental radiograph.

The developer solution is involved in the initial developing of the exposed film by converting the exposed crystals into black metallic silver but does not have a role in removing the unexposed crystals. Rinse solution is typically used to wash the film between processing steps but does not actively remove unexposed crystals. Preservative solution is not relevant in the context of film processing; rather, it may be used in certain dental materials to prevent degradation. Thus, the fixer solution is the only option that directly addresses the removal of unexposed silver halide crystals.