Removable barrier devices for covering an intraoral scanner. The barrier device includes a cover that is adapted to fit over a probe of the scanner. The cover includes a distal portion having walls defining an internal cavity for accommodating a distal end of the probe and formed of a first material, wherein at least one of the walls includes at least one window for allowing transmission of an optical signal between the probe and an external environment. The cover also includes a proximal portion coupled to the distal portion. The barrier device also includes a flexible sleeve adapted to cover a handle of the scanner, the flexible sleeve coupled to the proximal portion of the cover at an interface region configured to prevent fluid from passing through the barrier device between the cover and the sleeve.