A device for drying a root canal includes a cannula configured to inject a gas stream into the root canal. The cannula is a conduit having a proximal end in fluidic communication with a distal end. A handpiece is configured to removably hold the proximal end of the cannula at a distal handpiece end. A gas stream source is connectable to a proximal end of a tube. A distal end of the tube is connectable to the proximal handpiece end. A cut-off valve is disposed within the handpiece in fluidic communication in series between the distal handpiece end and the proximal handpiece end. The cut-off valve is configured to cut off the gas stream flowing through the handpiece. A manually-controlled operating element is mechanically coupled to the cut-off valve, where the operating element is configured to be controlled by a dentist or technician holding the handpiece.
