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US 7,255,562 B2Granted
Dental mill blanks
Assignee3M Innovative Properties Company
InventorsRichard P. Rusin, Kevin M. Cummings, Roger J. Carufel
Life of this patent
Estimating the term…
Abstract
A dental mill blank comprising a resin and a filler, wherein the blank is fabricated such that it passes a Thermal Shock Test. The mill blank is substantially free of cracks and discontinuities. Further, the blank may have superior cuttability and hardness.
Claims23
A method of making a dental mill blank suitable for the oral environment comprising:
- mixing a paste comprising a resin and a filler,
- adding a fluoride releasing material to the pastes,
- shaping the paste into a desired configuration,
- minimizing material discontinuities from the paste,
- curing the paste into a blank, and
- heating the blank to a temperature at or above the Tg of the resin for a time sufficient to relieve internal stresses in the blank, wherein the cured mill blank, when immersed in liquid nitrogen for about two minutes, does not explode and no cracks are observed upon visual inspection.
3 more elements
A method of making a dental prosthetic comprising:
- mixing a paste comprising a resin and a filler,
- shaping the paste into a desired blank configuration,
- minimizing material discontinuities from the paste,
- curing the paste into a blank,
- heating the blank to a temperature at or above the Tg of the resin for a time sufficient to relieve internal stresses in the blank, and
- carving the blank into a desired shape and morphology, wherein the blank is substantially free of cracks and when immersed in liquid nitrogen for about two minutes, does not explode and no cracks are observed upon visual inspection.
3 more elements
Dependencies are inferred from the claim text.