What is the primary halide used in dental x-ray film?

The primary halide used in dental x-ray film is bromide. This choice is correct because bromide is more sensitive to light and radiation than iodide or chloride, making it ideal for capturing the images needed in dental radiography.

Bromide salts, typically silver bromide, are the active components in the emulsion layer of the film. This high sensitivity allows for the use of lower radiation doses during exposure, helping to minimize the patient's exposure to x-rays while still producing clear and detailed images.

Other options, such as iodide, although they have some application in photography, do not provide the same level of sensitivity for dental x-rays. Chloride and fluoride are not used in dental x-ray film due to their lower effectiveness in capturing the necessary image quality in this particular application. Therefore, the choice of bromide is integral to ensuring both effective imaging and patient safety in the dental field.