I agree that digital impressions are equivalent to final impressions.  A licensed doctor needs to be present to ensure patient safety.  An ill fitting device can cause gingival trauma and/or food impaction.   A noncleansable area will occur with poor impression technique/data causing a cascade of problems that could have been prevented.   Furthermore, the occlusion of the impression is vital.  It is unlikely for a non licensed person to evaluate if the digital scan occlusion is correct.  There is not a day that goes by that a patient, in my chair, closes incorrectly.  I have my patients practice with me present. Different occlusions are needed depending on each patient's unique problems, infections, and skeletal differences.  Appliances that fit in the oral environment have to be constructed with the TMJ in mind.  A technician cannot see the TMJ in digital or physical impressions and rely on the ON SITE Dentist to ensure correct TMJ alignment. Only by being present, can a dentist verify that the scan is correct for the teeth, but more importantly, for the skeletal relationship of the TMJ.  TMD can cause debilitating pain and is much easier to prevent in the first place than fix after the appliance has caused the damage.