I believe that digital impressions will be the next big thing in digital high tech dentistry. The linked DrBicuspid article discusses breakthroughs in the technology that help eliminate the issues of blood and saliva on the teeth. Amazing.
While light-based intraoral scanning systems offer many advantages over conventional impressioning, they still have one great disadvantage: Moisture, blood, and saliva can get in the way, making subgingival margins difficult to capture. Most also require special powdering and complete dryness to optimize the reflective properties of the teeth…Ultrasound can penetrate periodontal tissue, saliva, and blood, helping improve cast precision for the CAD/CAM manufacturing process. An ultrasound-based method is therefore a noninvasive method of intraoral digital impressions with no adverse effect on the periodontium
via DrBicuspid Imaging.