Semi-thermoplastic molding composition having heat-stable custom shape memory
AssigneeMinnesota Mining and Manufacturing Company
InventorsJoel D. Oxman, Lani S. Kangas, F. Andrew Ubel, III
Life of this patent
Estimating the term…
Abstract
Thermoplastic molding compositions are made from a mixture of thermoplastic material (for example, polycaprolactone), a free-radically polymerizable resin (for example, a urethane diacrylate oligomer), and free-radical initiator (for example, a visible-light cure photoinitiator). The mixture is solid at 38.degree. C., has a melting or softening point that comfortably can be withstood by oral tissues, and can be imprinted with a heat-stable custom shape memory and semi-thermoplastic properties by shaping the composition to a desired shape and then causing or permitting the resin to undergo polymerization.
Claims12
A dental crown or bridge, said crown or bridge being formed from a composition comprising a thermoplastic, free radically polymerizable material and a free-radical initiator, the composition being solid at 38.degree. C. and having a melting or softening point at a temperature less than 75.degree. C., the composition having semi-thermoplasticity and hot custom memory after the material is polymerized.
A method for making a crown or bridge, comprising the steps of:
- a) heating a molding composition to a molten or softened state, said composition comprising a thermoplastic, free-radically polymerizable material, and a free-radical initiator, the composition being solid at 38.degree. C. and having a melting or softening point that comfortably can be withstood by oral tissues,
- b) shaping said molten or softened molding composition to the form of a crown or bridge, and in either order,
- c) cooling the composition so that it solidifies and
- d) causing or permitting the free-radically polymerizable material to undergo polymerization,
- whereby a semi-thermoplastic crown or bridge having hot custom memory is obtained.
Dependencies are inferred from the claim text.