Methods for making layered dental appliances from the outside in
A system and method for making a layered dental appliance. The system can include a first portion comprising a negative of a first layer of a layered dental appliance, and a second portion comprising a positive shape of a second layer of the layered dental appliance. The method can include providing a mold comprising a negative of an outer shape of a layered dental appliance, and positioning a slurry in the mold, forming a first layer of the layered dental appliance. The method can further include providing a solid structure comprising a positive shape of a second layer of the layered dental appliance, and pressing the solid structure into the slurry in the mold.
1. A method for making a layered dental appliance, the method comprising:
providing a mold comprising a negative of an outer shape of the layered dental appliance;
positioning a slurry in the mold, forming a first layer of the layered dental appliance, the slurry comprising:
(i) at least one of a glass powder and a glass ceramic powder, present in an amount of about 60 wt.-% to about 85 wt.-%,
(ii) a liquid, and
(iii) an inorganic binder precursor;
providing a solid structure comprising a positive shape of a second layer of the layered dental appliance, wherein the solid structure includes a stamp;
pressing the solid structure into the slurry in the mold; and
removing the solid structure from the slurry to form a cavity comprising a negative of the second layer in the slurry.
2. The method of claim 1 , further comprising using the cavity as a mold for the second layer of the dental appliance.
3. The method of claim 1 , wherein the slurry is a first slurry, and further comprising positioning a second slurry in the cavity to form the second layer of the layered dental appliance.
4. The method of claim 3 , further comprising pressing a dental core into the second slurry, such that the core forms at least a portion of a third layer of the layered dental appliance.
5. The method of claim 3 , further comprising:
providing a second solid structure comprising a positive shape of a third layer of the layered dental appliance; and
pressing the second solid structure into the second slurry.
6. The method of claim 5 , wherein the second solid structure includes a second stamp, and further comprising removing the second solid structure from the second slurry to form a second cavity comprising a negative of the third layer in the second slurry.
7. The method of claim 6 , further comprising positioning a third slurry in the second cavity to form a third layer of the dental appliance.
8. The method of claim 6 , further comprising using the second cavity as a mold for the third layer of the dental appliance.
9. The method of claim 1 , wherein the first layer forms the outermost layer of the layered dental appliance.
10. The method of claim 1 , further comprising activating the slurry prior to positioning the slurry in the mold.
11. The method of claim 1 , further comprising initiating a sol-gel reaction in the slurry prior to positioning the slurry in the mold.
12. The method of claim 1 , further comprising:
removing the layered dental appliance from the mold; and
firing the layered dental appliance,
wherein firing the first article includes firing the first article at a temperature of at least 500 ° C.
13. The method according to claim 1 , the inorganic binder precursor being selected from orthosilicates, silica sol, water glass, mixtures and combinations thereof.
14. The method according to claim 1 , wherein the mixture is essentially free of polymerizable organic binder components.
15. The method according to claim 1 , further comprising:
removing the layered dental appliance from the mold; and
machining the dental appliance.
16. The method according to claim 15 , wherein machining the dental appliance includes machining the dental appliance prior to sintering the dental appliance.