Method for molding dental restorations and related apparatus

• US 6,376,397 B1
• Filed: 10/10/2000
• Issued: 04/23/2002
• Est. Priority Date: 05/31/1994
• Status: Expired due to Term

• Current Assignee: TEC Ventures, Inc.
• Original Assignee: TEC Ventures, Inc.
• Inventors: Petticrew, Richard W.
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): STEIN, STEPHEN J
• Application Number:
  US09/685,400
• Time in Patent Office: 560 Days
• Field of Search: 501/5, 106/35, 433/177, 433/199.1, 433/201.1, 433/202.1, 433/212.1, 433/222.1, 433/228.1
• US Class Current: 501/5
• CPC Class Codes: A61C 13/20 Methods or devices for soldering, casting, moulding or melting A61C13/04, A61C13/081 take precedence
• CPC Class Codes: B28B 1/24 by injection moulding injection moulding of ceramic slips B28B1/265; of tubular articles B28B21/38
• CPC Class Codes: B28B 5/04 in moulds moved in succession past one or more shaping stations on turn-tables B28B5/06
• CPC Class Codes: C03C 10/00 Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 4/0021 for dental use
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]

Abstract

The present invention is concerned with a process for the formation of dental restorations from glass-ceramic materials and the resulting dental restorations. In this invention, a dental restoration is prepared by placing a glass-ceramic material in a heat-pressure deformable crucible. Heat is then applied to the crucible in order to bring the glass-ceramic material to a working range at temperatures above its liquidus temperature. The crucible in which the glass-ceramic material is placed has heat-pressure deformation properties which are matched to the working temperature of the glass-ceramic materials being heated. The heat deformation properties of the crucible must be such that when the glass-ceramic material in the crucible is in the working range the crucible is heat-pressure deformable without rupturing. Once the glass-ceramic material is heated to its working temperature, the crucible is brought into contact with a mold having a preformed cavity therein, the cavity being in the shape of the desired dental restoration. As the distance between the heated glass-ceramic material and the mold is decreased, the crucible is deformed to form a seal with the mold thereby facilitating the injection of the molten glass-ceramic material into the mold cavity. An interactive seal between the crucible and the mold may be provided for. The composite process may be carried out in a vacuum. The resulting dental restoration has superior optical, esthetic and strength properties.

Claims

1. A dental restoration which is formed from a glass-ceramic material having the following composition (by weight percent);

5. The dental restoration of claim 1 wherein the dental restoration has a M.O.R. of at least 30 K.S.I.

2. A dental restoration which is formed from a glass-ceramic material having the following composition (by weight percent)

6. The dental restoration of claim 2 wherein the dental restoration has a M.O.R. of at least 30 K.S.I.

3. A dental restoration which is formed from a glass ceramic material having the following composition (by weight percent);

7. The dental restoration of claim 3 wherein the dental restoration has a M.O.R. of at least 30 K.S.I.

4. A dental restoration which if formed from a glass ceramic material having the following composition (by weight percent),

8. The dental restoration of claim 4 wherein the dental restoration has a M.O.R. of at least 40 K.S.I.