There are two main types of dental x-rays: intraoral (images taken with x-ray film inside the mouth) and extraoral (images taken with the x-ray film outside the mouth).
Intraoral x-ray films are the most regularly used by the dentist to take Periapical, Bitewing and Occlusal views.
Extraoral x-rays films (in various sizes) are used to detect dental problems in the jaws.
All films will need developer & fixer solutions for processing. These are also available.