Ascentcare Dental Products Inc v. Solmetex LLC

1. Case Identification

• Case #: IPR2025-01065
• Patent #: 11,826,217
• Filed: June 6, 2025
• Petitioner(s): Ascentcare Dental Products, Inc.
• Patent Owner(s): Solmetex, LLC
• Challenged Claims: 1-11, 13-23

2. Patent Overview

• Title: DENTAL MOUTHPIECE
• Brief Description: The ’217 patent describes a dental isolation mouthpiece used to retract a patient's cheek and tongue while removing fluids and debris from the oral cavity during dental procedures. The device features a main body with anterior and posterior walls defining an interior space, a suction connector, a cheek retractor, and partial "intervening walls" with alternating crests and troughs that extend from the edges of the main body.

3. Grounds for Unpatentability

Ground 1: Obviousness over Nguyen in view of Black - Claims 1-11, 13-23 are obvious over Nguyen in view of Black.

• Prior Art Relied Upon: Nguyen (Patent 8,911,232) and Black (Patent 8,029,280).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Nguyen, invented by the same lead inventor as the ’217 patent, discloses a nearly identical dental mouthpiece. Nguyen teaches all major structural elements of independent claims 1 and 17, including the main body, anterior and posterior walls, suction connector, and cheek retractor. The critical distinction is that Nguyen’s mouthpiece features fully enclosed superior and inferior sidewalls, whereas the ’217 patent claims two partial, unconnected "intervening walls" that extend only "partially across" the interior space. Black discloses a similar dental isolation mouthpiece with an open-sided design. The proposed combination modifies Nguyen’s enclosed sidewalls to be open-sided, as taught by Black.
  • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine the teachings for three primary reasons. First, modifying Nguyen to have open sides, as taught by Black, would improve suction and aspiration of fluids and debris. Second, Nguyen’s enclosed "pocket" design is difficult to clean, and since the device is taught as reusable and autoclavable, creating open sides would make it predictably easier to clean. Third, the enclosed flexible sidewalls of Nguyen cause the inner anterior wall to buckle and crease when the device is bent in a patient's mouth, which can narrow or block suction channels; an open-sided design would prevent this buckling.
  • Expectation of Success: A POSITA would have had a high expectation of success because the modification involves a simple, known technique (creating open sides) applied to a known device (Nguyen) to achieve predictable results. Petitioner contended that a POSITA could achieve the claimed invention simply by cutting Nguyen’s existing sidewalls down the middle. This simple cut would inherently create two partial intervening walls, and the circular perforations already present in Nguyen's sidewalls, when bisected, would form the claimed "alternating crests and troughs."

Ground 2: Obviousness over Nguyen, Black, and Hirsch - Claims 8 and 19 are obvious over Nguyen in view of Black and Hirsch.

• Prior Art Relied Upon: Nguyen (Patent 8,911,232), Black (Patent 8,029,280), and Hirsch (Patent 9,532,858).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addresses dependent claims 8 and 19, which add the limitation of a "bite block integrated to the suction connector portion" that provides crush resistance. Petitioner argued that while Nguyen teaches a detachable mouth prop (bite block), it may not be considered "integrated." Hirsch, however, explicitly teaches a bite piece that is integrated into its suction connector section.
  • Motivation to Combine: If Nguyen’s detachable bite block is not considered "integrated," a POSITA would have found it obvious to make it integral with the main body. Hirsch provides the teaching for an integrated bite block. Making the component integral is an obvious engineering choice to create a one-piece construction, which reduces manufacturing complexity and eliminates the risk of a detachable part being lost or swallowed.

• Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 3) against claims 17-23 over Nguyen in view of Hirsch. This ground relied on a similar rationale to Ground 1, arguing a POSITA would have been motivated to modify Nguyen's enclosed sidewalls to be open-sided as taught by Hirsch to improve suction and cleanability.

4. Key Claim Construction Positions

• Petitioner argued for a specific construction of the term "partially across the distance of the interior space" as meaning "only partly, and not entirely, across the distance of the interior space."
• This construction was asserted as critical to the invalidity analysis. Petitioner contended that during prosecution of the ’217 patent, the Patent Owner distinguished the claims from prior art (specifically, a device like Nguyen) by emphasizing that the prior art sidewalls spanned the entire distance between the anterior and posterior walls, whereas the claimed invention's walls only extended partially.

5. Key Technical Contentions (Beyond Claim Construction)

• A central technical argument was that the enclosed sidewall design of the primary reference, Nguyen, has a functional flaw. Petitioner argued that because the mouthpiece is made of flexible material, bending forces within a patient’s mouth would cause the inner (anterior) wall of Nguyen to buckle and collapse inward, creasing at its weakest points.
• This buckling would physically obstruct or narrow the suction channels within the mouthpiece, degrading its primary function. Petitioner contended a POSITA would recognize this flaw and be motivated to adopt an open-sided design (from Black or Hirsch) to allow the anterior and posterior walls to bend independently, thus preventing buckling and maintaining clear suction pathways.

6. Arguments Regarding Discretionary Denial

• Petitioner noted that, pursuant to PTAB guidance, it was omitting any preemptive arguments against discretionary denial under §314(a) or §325(d). Petitioner stated its intent to present any such arguments in an Opposition Brief should the Patent Owner file a Discretionary Denial Brief.

7. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-11 and 13-23 of the ’217 patent as unpatentable under 35 U.S.C. §103.