Metal utensils that will be used to handle food that's to be consumed generally need first to be immersed in a mikvah ("toyveled") (if owned by a Jew). If the food or utensil is hot, the utensil must be used only for meat, only for dairy, or neither: not both. Once used hot for meat, it becomes a "meat" utensil, and unusable for dairy; and vice versa.
What is the halachic status of dental instruments owned by a Jew? Do dental instruments need to be toyveled? Can they become meat/dairy if they come into contact with hot portions of food in a patient's mouth?