PTAB

IPR2025-00819

ClearCorrect Operating LLC v. Align Technology Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Dental Appliances with Multilayer Polymer Shells
  • Brief Description: The ’384 patent relates to orthodontic appliances for positioning a patient’s teeth. The appliances are formed from a multilayer polymer sheet comprising at least three layers, including both hard and soft polymer layers with specific claimed mechanical properties.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tadros, Kalili, and Texin 990R - Claims 1-4, 7-14, 17-24, and 27-30 are obvious over Tadros in view of Kalili and Texin 990R.

  • Prior Art Relied Upon: Tadros (Application # 2005/0100853), Kalili (Application # 2011/0020761), and Texin 990R (a 2002 product information sheet).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Tadros disclosed a three-layer "soft-hard-soft" dental appliance with a central hard layer made of a polycarbonate-copolyester mixture, which meets nearly all limitations of the independent claims. Tadros’s hard layer was alleged to have the claimed flexural modulus. The specific properties for the soft layers, particularly the thermoplastic polyurethane (TPU) elastomer with an elongation at break greater than 200% and a specified hardness range, were taught by Kalili’s disclosure of the TEXIN 990R polymer, with specific values provided by the Texin 990R datasheet.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Tadros’s known three-layer aligner structure with the specific high-performance soft material (TEXIN 990R) taught by Kalili. Both references address multilayer dental aligners and seek to optimize materials for performance and comfort. A POSITA would have been motivated to incorporate the "outstanding" properties of TEXIN 990R, as described in Kalili for the same application, into the established aligner structure of Tadros to improve its characteristics.
    • Expectation of Success: A POSITA would have a reasonable expectation of success. Kalili taught the suitability of TEXIN 990R for use as a soft layer in dental aligners, and its specific mechanical properties were well-defined in its product datasheet, making the outcome of the combination predictable.

Ground 2: Obviousness over Kalili, Porter, Wen, and Texin 990R - Claims 1-2, 4, 6-12, 14, 16-22, 24, and 26-30 are obvious over Kalili in view of Porter, Wen, and Texin 990R.

  • Prior Art Relied Upon: Kalili (Application # 2011/0020761), Porter (a Dec. 2007 article), Wen (WO 2006/096558), and Texin 990R (a 2002 product information sheet).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented to address an alternative "soft-hard-hard" layer configuration. Petitioner asserted that Kalili disclosed a base two-layer (soft-hard) aligner using a polycarbonate hard layer and a TPU soft layer (TEXIN 990R). Wen taught the benefits of splitting a single thick layer into multiple thinner layers to improve thermoforming and interlayer bonding. Porter taught replacing polycarbonate with a superior, BPA-free Tritan copolyester that has the claimed mechanical properties for the hard layer. The combination resulted in a three-layer appliance (one soft TEXIN 990R layer, two hard Tritan layers) that met the challenged claims' limitations.
    • Motivation to Combine: A POSITA would combine Kalili and Wen to improve the manufacturing and performance of a multilayer aligner by splitting the hard layer. The resulting structure would then be modified based on Porter's teachings, substituting the known polycarbonate with the improved Tritan copolyester to enhance safety (BPA-free) and durability. This represents a simple substitution of one known material for another to obtain predictable advantages.
    • Expectation of Success: Success was predictable because Wen explicitly taught the benefits of using thinner sublayers, and Porter provided clear reasons and data supporting the substitution of Tritan for polycarbonate in similar applications.

4. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner contended that a POSITA would understand that certain manufacturing techniques, such as adhesive lamination, would preserve the mechanical properties of individual polymers as reported in manufacturer datasheets (e.g., Texin 990R, Porter). This contention was central to Petitioner's argument that properties disclosed for standalone materials could be used to satisfy the limitations for layers within the final, composite multilayer appliance.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued the Board should not exercise its discretion to deny institution under 35 U.S.C. §314(a). It stipulated that if an inter partes review (IPR) is instituted, it and all co-defendants in the parallel district court litigation will not pursue any invalidity ground that was raised, or could have been reasonably raised, in the petition. This stipulation was intended to address the Fintiv factors concerning efficiency and overlap with co-pending litigation.

6. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-4, 6-14, 16-24, and 26-30 of the ’384 patent as unpatentable.