What is the difference between a PVS impression and a digital scan?

PVS impressions have been the clinical standard for decades. When taken correctly, they achieve roughly 25 microns of accuracy, but that number degrades fast: tray seating errors, premature removal, voids from moisture contamination, and shipping damage during the 2-5 day transit window all compound. By the time the lab receives a poured stone model, the original clinical geometry may have shifted measurably. For full-arch implant cases especially, that cumulative error is clinically significant.

Digital intraoral scans (systems like iTero Element 5D, 3Shape TRIOS 5, and Medit i700) capture the arch as a point cloud resolved into an STL or PLY mesh, typically within 15-20 microns of accuracy across a single-unit scan. Full-arch accuracy depends on scanning technique and stitching algorithm, but modern scanners achieve clinical acceptability for implant-level restorations when protocol is followed. The file transmits to the lab immediately, cutting average case turnaround by 1-2 days compared to traditional impression workflows.

For a restorative dentist running 20-plus crown cases per month, the math is straightforward. Digital scan eliminates impression material cost, stone cost, and pour labor. It also eliminates the remake risk tied to a damaged or distorted impression in transit. Dani Dental accepts both workflows with no fee differential, and scan files route directly into the CAD design queue the same business day they arrive.