Dentsply Sirona Inc v. Osseo Imaging LLC

1. Case Identification

• Case #: IPR2025-00771
• Patent #: 6,381,301
• Filed: March 26, 2025
• Petitioner(s): Dentsply Sirona Inc.
• Patent Owner(s): Osseo Imaging, LLC.
• Challenged Claims: 1-8 and 10-20

2. Patent Overview

• Title: Dental and Orthopedic Densitometry Modeling System and Method
• Brief Description: The ’301 patent discloses systems and methods for tomographically modeling the density of dental and orthopedic structures. The invention purports to apply known computed tomography (CT) and densitometry techniques to dental applications for diagnosing conditions and monitoring prostheses.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1-8 - Claims 1-8 are obvious over Arai in view of Cann.

• Prior Art Relied Upon: Arai (Patent 6,118,842) and Cann ("Precise Measurement of Vertebral Mineral Content Using Computed Tomography," a 1980 journal article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Arai, which discloses a dental X-ray imaging apparatus capable of performing CT scans, teaches all the structural elements of independent claim 1. Arai’s system includes a controller with a microprocessor and memory (“controlling means 170”), an input device (“input means 174”), positioning motors, and X-ray equipment (source and sensor). Petitioner contended that Arai’s system is inherently capable of generating quantitative data (CT numbers) related to bone density. Dependent claims 2-4 and 6 were argued to be anticipated by Arai's disclosure of three-axis movement, an A/D converter, a merger device inherent to CT processing, and a pre-programmed scan path.
  • Motivation to Combine: Petitioner asserted that Cann teaches using quantitative CT, including dual-energy scans and calibration with phantoms, to precisely measure bone mineral density. A person of ordinary skill in the art (POSA) would combine Arai's dental CT system with Cann’s quantitative densitometry methods to achieve more accurate and precise density models, a known goal in the field. This combination would make Arai's system more versatile for dental diagnosis, a purpose Arai itself suggests. The ’301 patent’s admissions regarding the known benefits of dual-energy scanning for densitometry further supported this motivation for claims 5, 7, and 8.
  • Expectation of Success: A POSA would have had a reasonable expectation of success in this combination. The use of CT for densitometry was well-established by the patent’s priority date (nearly 20 years after Cann’s publication), and the required modifications, such as adding a calibration phantom, were minimal and well-understood.

Ground 2: Anticipation and Obviousness of Claims 1-6 - Claims 1-6 are anticipated by Pelc or, in the alternative, obvious over Pelc in view of Cann.

• Prior Art Relied Upon: Pelc (WO 94/10908) and Cann.

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Pelc anticipates claims 1-6. Pelc discloses a "Compact C-Arm Tomographic Bone Scanning System" for evaluating bone density and morphology. Petitioner mapped each element of independent claim 1 directly to Pelc’s system: the "electronic computer" is the controller with inherent memory; the "mass storage device" provides means for storing pre-existing models; the "operator console" with a keyboard is the input device; the C-arm and gantry motors are the positioning motors; the radiation source and detector are the X-ray equipment; the CRT display is the output device; and the system’s digital nature implies an A/D converter. Pelc's system, which performs CT scans for bone evaluation, was argued to be inherently quantitative.
  • Motivation to Combine (for obviousness alternative): In the event Pelc was found not to be inherently quantitative, Petitioner argued it would be obvious to combine Pelc with Cann. A POSA would have been motivated to apply Cann’s explicit teachings on quantitative CT densitometry to Pelc’s bone scanning system to obtain more accurate densitometry models, as both references relate to tomographic evaluation of bone density.
  • Expectation of Success: A POSA would have expected success in combining Pelc and Cann, given the established use of quantitative CT for densitometry and the minimal modifications required to implement Cann's phantom-based calibration methods in a system like Pelc.

• Additional Grounds: Petitioner asserted additional obviousness challenges for method claims 10-20 based on Arai and Pelc. These grounds added references like Xu (Patent 6,363,163) and Milestone (WO 98/36683) for their teachings on comparing current and pre-existing medical scans, and Rothman (a 1998 treatise) for its teachings on specific dental applications of CT, such as detecting caries and fractures.

4. Key Claim Construction Positions

• "Tomographically modeling/tomographic model(s)" (Claims 1, 10, 20): Petitioner adopted a construction from a prior district court proceeding: "Merging information from multiple tomographic scans of an object to produce a representation of the subject/said representation depicting quantitative density differences of the object scanned, which is created by the microprocessor in the controller using densitometry from at least one focal plane." Petitioner emphasized the court's finding that "quantitative" does not require a specific bone mineral density (BMD) calculation but that any quantitative densitometric calculation would suffice, such as standard CT numbers.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under Fintiv is inappropriate. It was asserted that the co-pending district court litigation is at a very early stage, as no answer had been filed and no trial date or other substantive deadlines had been set.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-8 and 10-20 of the ’301 patent as unpatentable.