System And Method For Manufacturing A Dental Prosthesis And A Dental Prosthesis Manufactured Thereby
Patent No. US11197739 (titled "System And Method For Manufacturing A Dental Prosthesis And A Dental Prosthesis Manufactured Thereby") was filed by Align Technology Inc on Jul 17, 2019.
What is this patent about?
’739 is related to the field of dental prosthetics, specifically the fabrication of dental restorations like crowns and bridges. Traditional methods involve manual creation, which can be imprecise, while existing CNC methods often involve removing material from a solid block or applying layers directly, each with its own limitations in terms of material usage and achieving natural-looking multi-layered prostheses.
The underlying idea behind ’739 is to use successive wax layers as molds for creating the final prosthesis layers. Instead of directly machining the final material, each wax layer is shaped using CNC machining and then used to create a mold for casting or molding the corresponding prosthesis layer. This allows for greater precision and the creation of complex, multi-layered structures.
The claims of ’739 focus on a method and system for manufacturing a dental prosthesis by generating a 3D virtual model of the prosthesis with at least two layers. A first wax model is produced corresponding to the first virtual layer by material removal operations. This wax model is then used to produce a first prosthesis layer. A second wax model is then produced on the first prosthesis layer, and the final dental prosthesis is produced based on the two wax models.
In practice, the process begins with a coping, which is a substructure fitted onto the prepared tooth. A wax layer is applied to the coping, and CNC machining is used to shape the wax into the desired form for the first layer of the prosthesis. This wax layer then serves as a mold for casting or molding the first prosthesis layer from a suitable material like metal or ceramic. Subsequent wax layers are applied and machined on top of the previous prosthesis layer, each acting as a mold for the next layer, allowing for the creation of multi-layered prostheses with varying material properties and aesthetics.
This approach differs from prior methods by using wax not just as a temporary form but as an integral part of the manufacturing process, enabling the creation of precise molds for each layer. This allows for finer details and smoother surface textures compared to directly machining the final prosthesis material. Furthermore, the use of wax reduces wear on the machining tools and minimizes deviations from the intended dimensions, leading to more accurate and durable dental prostheses. The lost-wax casting process is thus combined with modern CNC techniques.
How does this patent fit in bigger picture?
Technical landscape at the time
In the early 2000s when ’739 was filed, dental prostheses were often manufactured using CNC milling machines, at a time when systems commonly relied on removing material from a solid block based on a 3D numerical model. The use of CAD/CAM systems to control the machining paths was known, and layering techniques were also employed, where each layer was machined after application. The creation of 3D digital models of the patient's dentition was typically performed using optical scanners.
Novelty and Inventive Step
The application was a continuation of several prior applications. Claims were rejected under 35 U.S.C. 112 for failing to comply with the enablement requirement. Some claims were allowed, and others were rejected. The examiner stated reasons for allowance based on differences from prior art. The prosecution record does not describe the technical reasoning or specific claim changes that led to allowance.
Claims
This patent contains 20 claims, of which claims 1 and 12 are independent. The independent claims are directed to a method and a system for manufacturing a dental prosthesis using virtual models and wax models. The dependent claims generally elaborate on specific features, components, or steps of the method and system described in the independent claims.
Key Claim Terms New
Definitions of key terms used in the patent claims.
Patent Family
File Wrapper
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
Date
Description
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US11197739
- Application Number
- US16514908
- Filing Date
- Jul 17, 2019
- Status
- Granted
- Expiry Date
- Dec 1, 2025
- External Links
- Slate, USPTO, Google Patents