Comparison of the Hardness of Novel Experimental Vinyl Poly Siloxane (VPS) Impression Materials with Commercially Available Ones.

Continued polymerisation of elastomeric impression materials results in increased hardness over time. Hardness, Young's moduli, and rigidity of the set commercial and experimental VPS materials were within the required limits. Shore A hardness and Young's moduli were directly proportional to each other, and commercial and experimental materials had enough rigidity to contain the stone during pouring.