PTAB

IPR2025-00818

ClearCorrect Operating LLC v. Align Technology Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Dental Appliances and Methods
  • Brief Description: The ’613 patent discloses methods for making multilayer dental appliances used for positioning a patient's teeth. The appliances are fabricated by thermoforming a polymer sheet comprising at least three layers, including "hard" and "soft" polymer layers with specific mechanical properties.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tadros, Kalili, and Texin 990R - Claims 1-2, 4, 6-10, 12-18, and 20-22 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 method of making a three-layer dental appliance with a "soft-hard-soft" configuration, which is the sole configuration described in the ’613 patent's specification. Tadros taught a hard central layer made of a copolyester mixture with a flexural modulus greater than 150,000 psi, and soft outer layers made of an elastomer like polyurethane. Petitioner contended that Tadros taught or rendered obvious every limitation of independent claims 1 and 20 except for the specific mechanical properties of the soft layer (elongation at break >200% and a specified hardness range). Kalili, which disclosed a two-layer dental appliance, was cited for its teaching of using a specific thermoplastic polyurethane (TPU) elastomer, TEXIN 990R, as a soft layer. The Texin 990R product sheet confirmed that this material possessed the exact mechanical properties required by the challenged claims.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the teachings because both Tadros and Kalili addressed the same technical problem: creating improved multilayer dental aligners. A POSITA would have been motivated to use the specific TEXIN 990R material praised in Kalili for its "outstanding" properties (e.g., toughness, flexibility, structural memory) for the soft elastomeric layers in the three-layer appliance of Tadros to improve its performance.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because Kalili disclosed using TEXIN 990R for the same purpose—a soft layer in a dental aligner—yielding predictable results.

Ground 2: Obviousness over Tadros, Kalili, Texin 990R, and Wen - Claims 3, 5, 11, and 19 are obvious over Tadros in view of Kalili, Texin 990R, and further in view of Wen.

  • Prior Art Relied Upon: Tadros (Application # 2005/0100853), Kalili (Application # 2011/0020761), Texin 990R (a 2002 product information sheet), and Wen (WO 2006/096558).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination in Ground 1 to address claims requiring multiple sub-layers (e.g., a hard layer comprising at least two layers). Wen was introduced for its teaching that replacing a single thick polymer layer with multiple thinner layers of the same material improves the thermoforming process. Specifically, Wen taught that thinner layers conform more easily to tooth models and improve interlayer bonding, especially between materials with disparate properties.
    • Motivation to Combine: A POSITA would have been motivated to apply Wen’s teachings to the base combination of Tadros and Kalili. To gain the known benefits of improved tooth conformity and interlayer bonding described by Wen, a POSITA would replace the single hard central layer in the Tadros appliance with two or more thinner layers of the same material.
    • Expectation of Success: The expectation of success was high, as Wen provided a general principle for improving the fabrication of multilayer appliances that was directly applicable to the structure disclosed in Tadros.

Ground 3: Obviousness over Kalili, Porter, Wen, and Texin 990R - Claims 1-12, 15, and 18-22 are obvious over Kalili in view of Porter, Wen, and further in view of Texin 990R.

  • Prior Art Relied Upon: Kalili (Application # 2011/0020761), Porter (a 2007 article in Plastics Technology magazine), 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 challenge the claims based on a "soft-hard-hard" configuration that the Patent Owner allegedly asserted in co-pending litigation. The base reference, Kalili, disclosed a two-layer (soft-hard) appliance using a polycarbonate hard layer. Porter taught replacing polycarbonate, which contains harmful BPA, with Tritan copolyester—a safer, more durable, BPA-free alternative with similar mechanical properties. Wen, as in Ground 2, taught splitting a single hard layer into multiple thinner hard layers. The combination of Kalili, Porter, and Wen resulted in a three-layer "soft-hard-hard" appliance where the hard layers are Tritan copolyester and the soft layer is the TEXIN 990R material disclosed in Kalili.
    • Motivation to Combine: A POSITA would combine these references for clear reasons. First, a POSITA would replace the polycarbonate in Kalili's appliance with the Tritan copolyester from Porter to improve product safety (avoiding BPA) and durability, a known design choice in the field. Second, a POSITA would apply Wen's teaching to split the single hard Tritan layer into two thinner layers to gain the known manufacturing benefits of better conformity and adhesion.
    • Expectation of Success: There was a high expectation of success. Porter explicitly presented Tritan as a desirable replacement for polycarbonate, and Wen's teachings on using thinner layers were a well-understood technique to improve thermoforming outcomes.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should not exercise its discretion to deny institution. To address potential denial under the Fintiv factors, Petitioner stipulated that if an IPR is instituted for the ’613 patent, it will not pursue in the parallel district court case any invalidity ground that was raised or could have been reasonably raised in the petition.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-22 of the ’613 patent as unpatentable under 35 U.S.C. §103.