What type of impression material has the greatest dimensional stability?

The choice of polyvinyl siloxane (PVS) as the impression material with the greatest dimensional stability is based on its unique properties and behavior after setting. PVS materials are known for their excellent ability to maintain their dimensions over time, which is crucial for creating accurate dental impressions that will be used for fabricating restorations or prosthetics.

One of the key reasons PVS demonstrates superior dimensional stability is its hydrophobic nature, which reduces the likelihood of distortion from moisture or environmental changes. It also has low polymerization shrinkage, meaning that once the material sets, it retains its shape very well, minimizing any deformation.

Additionally, PVS can be stored for longer periods without significantly affecting its accuracy, making it a reliable option for dental professionals who require a material that can withstand time and handling. Its ease of use in both two-step and single-step techniques further contributes to its popularity and preference in clinical settings.

In contrast, other materials such as agar, polyether, and condensation silicone can exhibit more variations in dimensional change due to factors like moisture absorption or polymerization shrinkage, which makes them less stable over time compared to PVS. Thus, when considering the overall performance in terms of dimensional stability, PVS stands out as the optimal