Which of the following is NOT a type of elastomeric material?

Polyvinyl is not classified as an elastomeric material. Elastomeric materials are characterized by their rubber-like properties, allowing them to stretch and return to their original shape. The primary types of elastomeric impression materials include polysiloxane, polysulfide, and polyether, all of which possess these properties due to their chemical structure.

Polysiloxane is a type of silicone material known for its excellent dimensional stability and ability to capture fine details. Polysulfide is a rubber-like material that is highly flexible and has good tear strength, making it suitable for impressions. Polyether is another elastomeric material recognized for its hydrophilicity and good accuracy in capturing details.

In contrast, polyvinyl chloride (PVC) or polyvinyl acetate (PVA) materials do not exhibit the same elastic properties. While they may have some flexibility, they do not have the same extensive range of elastic recovery or are used in the same applications as elastomeric materials in dentistry. Thus, identifying polyvinyl as the option not fitting into the elastomeric category is accurate.