An understanding of the properties of the materials is essential for their proper use in the treatment of the prosthodontic patient. Unfortunately, this plastic behavior changes with time to a more elastic behavior as the ethanol and plasticizers leach out of the material and water is absorbed. The more elastic the material, the less it conforms to the changes of the alveolar tissue. Eventually, all these materials will become hard, rough, and clinically unacceptable. The selection of a material should then be based upon the diagnosis, treatment goals, and the individual characteristics or properties of the material.
Products differ in their flow characteristics, both initially, and over the passage of time.
It is difficult to discern the flow characteristics of a product from the label. Most products will continue to flow for periods of up to seven days. With a lesser degree of inflammation, a more viscous material, e.g., Viscogel, may be selected. Viscogel is unique in that the manufacturer recommends replacement within 30 days. A minimum thickness of 1 mm is necessary for effective tissue conditioning.