What is a PVS impression?

PVS material is an addition-cured silicone that cross-links without byproduct shrinkage, which is why it captures fine margin detail reliably down to approximately 25 microns. That precision matters most on preparations where a poorly captured margin means a remake. For single-unit crowns and multi-unit bridges, a well-executed PVS impression poured in type IV stone within 24 hours gives the lab a working die accurate enough to fabricate a restoration with marginal fit inside the 120-micron clinical threshold.

For general dentists sending casework to a lab, impression quality is one of the most controllable variables in the remake equation. Contamination from blood or sulcular fluid, inadequate tray adhesive, or premature removal before full set are the three most common sources of distortion. Labs that receive a compromised impression have two options: call the dentist to reshoot, or fabricate and risk a poor fit. A 2020 survey published in the Journal of Prosthetic Dentistry found impression error was cited as a contributing factor in 38 percent of crown remakes reviewed.

Digital intraoral scanning is replacing PVS in many practices, particularly for full-arch implant cases where soft-tissue displacement is difficult to manage with material. Dani Dental accepts both analog PVS impressions and digital STL scan files. For practices still on a PVS workflow, cases ship through standard courier with a two-week impression stability window before the file must be re-captured.