Orthodontic appliances including polycrystalline alumina-based ceramic material, kits, and methods
Assignee3M Innovative Properties Company
InventorsDarren T. Castro, Richard P. Rusin, William E. Wyllie II
Life of this patent
Estimating the term…
Abstract
An orthodontic appliance that includes a polycrystalline translucent aluminum oxide ceramic material having an average grain size of no greater than 1.0 micron and a Contrast Ratio value of less than about 0.7.
Claims23
An orthodontic appliance comprising a polycrystalline translucent aluminum oxide ceramic material having an average grain size of no greater than 1.0 micron and a Contrast Ratio value of less than about 0.7.
A kit comprising a plurality of orthodontic appliances, wherein at least one of the appliances comprise a polycrystalline translucent aluminum oxide ceramic material having an average grain size of no greater than 1.0 micron and a Contrast Ratio value of less than about 0.7.
A method for making an orthodontic appliance or appliance perform comprising a polycrystalline translucent aluminum oxide ceramic material having a grain size of no greater than 1.0 micron and a Contrast Ratio value of less than about 0.7, the method comprising:
- providing an aluminum oxide powder;
- forming the powder into an article having a desired shape;
- sintering the shaped article to obtain a sintered article having closed porosity;
- and
- subjecting the sintered article to hot isostatic pressing to further densify and form an orthodontic appliance or appliance perform comprising polycrystalline translucent aluminum oxide ceramic material having a grain size of no greater than 1.0 micron and a Contrast Ratio value of less than about 0.7.
Dependencies are inferred from the claim text.