PTAB

PGR2025-00058

Ascentcare Dental Products Inc v. Solmetex LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Dental Mouthpiece
  • Brief Description: The ’948 patent discloses a dental isolation mouthpiece used to retract a patient's cheek and tongue while providing continuous suction during dental procedures. The device comprises a main body with flexible anterior and posterior walls, a suction connector portion, and a cheek retractor portion.

3. Grounds for Unpatentability

Ground 1: Obviousness over Nguyen in view of Black - Claims 1-14, 17-24, and 28 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 argued that Nguyen, a patent by the same inventor, discloses a nearly identical dental mouthpiece that meets most limitations of the challenged claims. However, Nguyen teaches fully enclosed superior and inferior sidewalls that connect the anterior and posterior walls, spanning the entire distance between them. Black teaches a dental aspirator with open sidewalls. Petitioner contended that the key claimed feature—an "intervening wall" that extends only "partially across the distance" between the main walls—is achieved by the obvious modification of cutting Nguyen's fully enclosed sidewalls, as suggested by Black's open-sided design.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Nguyen and Black to solve known problems with Nguyen’s enclosed design. Black teaches that open sidewalls provide advantages like improved suction and greater flexibility. Petitioner argued a POSITA would recognize that Nguyen's enclosed, flexible walls could buckle within a patient's mouth, narrowing or blocking suction channels. Opening the sidewalls, as taught by Black, would prevent this buckling, improve fluid aspiration, and make the reusable device significantly easier to clean.
    • Expectation of Success: A POSITA would have a high expectation of success because the modification is a straightforward application of a known technique (open sides from Black) to a known device (Nguyen) to achieve the predictable results of improved suction and cleanability. The simplicity of cutting the existing sidewalls would yield the claimed open-sided structure without requiring a complete redesign.

Ground 2: Obviousness over Nguyen in view of Hirsch - Claims 1-3 and 5-31 are obvious over Nguyen in view of Hirsch.

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

  • Core Argument for this Ground:

    • Prior Art Mapping: Similar to the combination with Black, this ground asserted it would have been obvious to modify Nguyen's fully enclosed sidewalls based on Hirsch's teachings. Hirsch discloses a dental retractor with open sides and V-shaped grooves on its wall edges that function as both fluid inlets and an anti-collapse structure. Modifying Nguyen by replacing its enclosed sidewalls with a structure like that taught in Hirsch would result in the claimed invention.
    • Motivation to Combine: A POSITA would be motivated to combine the references to improve suction and make the device easier to clean, consistent with the motivations for using Black. Petitioner argued that a POSITA would understand that simply removing Nguyen's sidewalls would necessitate adding an anti-collapse structure at the edges to prevent the walls from sealing under suction. Hirsch's grooved wall provides a known, effective solution for both maintaining an open structure and allowing fluid intake along the edges.
    • Expectation of Success: Success was expected because this modification represents a simple substitution of one known element (Nguyen's enclosed sidewall) for another known element with predictable properties (Hirsch's grooved, open wall). This substitution would predictably obtain the benefits of an open-sided design while maintaining necessary structural integrity.

  • Additional Grounds: Petitioner asserted further obviousness challenges, including that claim 4 is obvious over Nguyen in view of Hirsch and Black, and that claims 15-16, 25-27, and 29-31 are obvious over the combination of Nguyen, Black, and Hirsch, with Hirsch teaching a longitudinal spine for enhanced cheek retraction. Petitioner also challenged claims 20-31 as invalid under 35 U.S.C. § 112 for lack of written description and indefiniteness, and claim 18 for indefiniteness.

4. Key Claim Construction Positions

  • "partially across the distance between the first wall and the second wall": Petitioner argued this term's plain and ordinary meaning, supported by the patent's specification and its prosecution history, is "only partly, and not entirely." This construction was asserted as critical for distinguishing the claims from the primary prior art reference, Nguyen, which discloses sidewalls spanning the entire distance between its anterior and posterior walls. This distinction formed a core basis of the obviousness arguments.

5. Relief Requested

  • Petitioner requests institution of post-grant review and cancellation of claims 1-31 of the ’948 patent as unpatentable.