Ascentcare Dental Products Inc v. Solmetex LLC

1. Case Identification

• Case #: IPR2025-01059
• Patent #: 11,744,686
• Filed: May 28, 2025
• Petitioner(s): Ascentcare Dental Products, Inc.
• Patent Owner(s): Solmetex, LLC
• Challenged Claims: 12-21

2. Patent Overview

• Title: Interoral Device
• Brief Description: The ’686 patent discloses a dental isolation mouthpiece designed to retract a patient's tongue and cheek while simultaneously evacuating fluids and debris from the oral cavity. The device features a main body with two walls forming an interior space, a suction connector, and a cheek retractor.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 12-15, 17-18, and 20-21 over Park, Baughan, and Johnson

• Prior Art Relied Upon: Park (Korean Patent No. KR10-1082826), Baughan (Patent 3,101,543), and Johnson (Patent 4,017,975).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Park, the primary reference, disclosed all elements of independent claim 12 except for the "bridge structure" with protrusions. Park taught an enclosed dental mouthpiece made of flexible silicone with a main body comprising first and second walls, a connecting wall, a suction connector with an interlocking cutout, and a cheek retractor. The key distinction was that Park was silent on internal anti-collapse structures. Baughan taught a saliva ejector with projecting, spaced-apart discs that prevent a flexible outer sleeve from collapsing onto a suction tube, with the discs forming a wave-like shape. Johnson taught forming integral projections on a flat surface of a dental apparatus via injection molding.
  • Motivation to Combine: Petitioner contended that a person of ordinary skill in the art (POSITA) would recognize that Park’s flexible, enclosed mouthpiece would be susceptible to collapsing under suction, which would block fluid flow. To solve this predictable problem, a POSITA would combine Park’s mouthpiece with the known anti-collapse solution from Baughan, modifying Baughan's projecting discs into protrusions on an interior wall of Park’s device. Johnson demonstrated the well-known method of making such projections integral with the device through injection molding, which was an obvious design choice.
  • Expectation of Success: A POSITA would have a high expectation of success, as adding simple mechanical spacers (from Baughan) to prevent the walls of a flexible chamber (from Park) from collapsing is a straightforward application of known principles to achieve a predictable result.

Ground 2: Obviousness of Claims 16 and 19 over Park, Baughan, Johnson, and Hirsch

• Prior Art Relied Upon: Park (Korean Patent No. KR10-1082826), Baughan (Patent 3,101,543), Johnson (Patent 4,017,975), and Hirsch (Application # 2003/0134253).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1 to address the "stability bar" limitation recited in dependent claims 16 and 19. While Park depicted a line along its longitudinal axis that could be a stability bar, Petitioner argued that Hirsch explicitly taught this feature. Hirsch disclosed a dental isolation mouthpiece with a "spine" running down its longitudinal axis to provide additional rigidity, resiliency, and assist in light dispersion.
  • Motivation to Combine: A POSITA would be motivated to add Hirsch's spine to the Park/Baughan/Johnson combination for the known benefits of increasing rigidity and resilience. This added stiffness would further prevent the device from collapsing under suction and would also help in retracting cheek tissue more effectively. Since both Park and Hirsch disclosed similar dental mouthpieces for the same purpose, incorporating this feature was a simple combination of known elements.
  • Expectation of Success: A POSITA would expect success in adding a reinforcing spine to a flexible mouthpiece, as this is a common and predictable method for improving the structural integrity of such devices.

4. Key Claim Construction Positions

• Petitioner argued that Patent Owner has asserted overly broad constructions for key terms during infringement contentions, deviating from the patent’s specification.
• For example, Patent Owner allegedly construed "connecting wall" to include a bite block, even though the patent describes the bite block (mouth prop) as a separate and detachable element from the main body.
• Petitioner contended that the claims were invalid under either party’s construction but adopted Patent Owner’s broad constructions for purposes of its invalidity arguments to demonstrate their overbreadth. This position was central to Petitioner's narrative that Patent Owner improperly broadened claim scope during prosecution to capture Petitioner's competing product.

5. Arguments Regarding Discretionary Denial

• Petitioner explicitly stated that it omitted any preemptive arguments against discretionary denial under §325(d) or §314.
• Petitioner noted it would present arguments in an Opposition Brief should Patent Owner file a Discretionary Denial Brief.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and a final written decision cancelling claims 12-21 of the ’686 patent as unpatentable under 35 U.S.C. §103.