Final answer:
The Bitewing film is the dental film used to show the teeth in occlusion with only the crowns visible, used for detecting decay and assessing bone density.
Step-by-step explanation:
The type of dental film that shows the teeth in occlusion with only the crowns visible is the Bitewing film. Bitewing radiographs are specifically designed to reveal the crowns of the posterior teeth and the height of the alveolar bone in the context of dental caries and bone level assessments, providing a unique view where the teeth can be seen in occlusion or when they come together. This type of film is used to help identify tooth decay between teeth and changes in bone density caused by gum disease, as well as to assist in the proper fit of dental restorations like crowns and fillings.