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Panoramic/orthopantamograph bite blocks are semicritical devices that contact oral mucosa. CDC dental-radiology guidelines state that if the bite block is not disposable it must be protected with a single-use, impervious plastic barrier (or be heat-sterilized) to prevent patient-to-patient cross-contamination. Studies of dental radiography accessories likewise show that covering sensors and bite blocks with impermeable plastic sheaths effectively blocks salivary contamination between patients [Kohn et al., 2003, PMID 14685139; Hubar & Gardiner, 2000, PMID 11410973].