While delivering a crown over an implant, the patient swallows the screw. What should you do?

Any swallowed or potentially aspirated foreign object during dental treatment requires prompt imaging (chest/abdominal X-ray) to confirm its location and rule out aspiration into the airway before deciding on observation versus retrieval — this is the standard protocol, rather than simply reassuring the patient that an unconfirmed object will 'pass through' on its own. The Heimlich maneuver and calling 911 are reserved for signs of acute airway obstruction/choking, which isn't described here.