Align Technology Inc v. 3Shape AS

1. Case Identification

• Case #: IPR2021-01312
• Patent #: 10,905,333
• Filed: July 30, 2021
• Petitioner(s): Align Technology, Inc.
• Patent Owner(s): 3Shape A/S
• Challenged Claims: 1, 3, 5, 7-8, 20-21, 23, 25, 27-28, and 38

2. Patent Overview

• Title: 3D Intraoral Scanner Measuring Fluorescence
• Brief Description: The ’333 patent discloses an intraoral scanning system that uses two different light wavelengths to create a digital 3D model of a patient's teeth. One wavelength is used to capture 3D surface topography, while the second is used to collect data corresponding to cariogenic (caries-causing) regions of a tooth.

3. Grounds for Unpatentability

Ground 1: Obviousness over Oota and Liang - Claims 1, 3, 5, 8, 20-21, 23, 25, 28, and 38 are obvious over [Oota](https://ai-lab.exparte.com/case/ptab/IPR2021-01312/doc/1006) in view of [Liang](https://ai-lab.exparte.com/case/ptab/IPR2021-01312/doc/1007).

• Prior Art Relied Upon: Oota (Application # 2010/0253773) and Liang (Application # 2008/0063998).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Oota taught a 3D intraoral scanner that used two light sources with different wavelengths to distinguish between different dental regions (e.g., enamel, dentin) based on surface reflectivity. Oota’s system generated a 3D representation from this data. Liang taught a system specifically for detecting cariogenic regions by using fluorescence, explaining that healthy and demineralized enamel exhibit different fluorescence under certain light wavelengths. The combination allegedly met the limitations of independent claims 1 and 21 by incorporating Liang’s fluorescence-based caries detection method into Oota’s foundational 3D scanning system.
  • Motivation to Combine: A POSITA would combine these references to improve Oota's general-purpose dental scanner with the specific, known benefits of Liang’s fluorescence-based caries detection. Oota itself suggested its principles could be applied to detect unhealthy regions, and there was significant interest in the art for improved caries detection. This combination would predictably enhance the diagnostic capabilities of Oota’s scanner.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because both Oota and Liang described similar optical systems using light sources, sensors, and processors to analyze optical responses from teeth. Integrating Liang’s known fluorescence detection filters and processing into Oota’s existing multi-wavelength scanner architecture was presented as a straightforward adaptation.

Ground 2: Obviousness over Babayoff - Claims 1, 3, 5, 7-8, 20-21, 23, 25, 27-28, and 38 are obvious over [Babayoff](https://ai-lab.exparte.com/case/ptab/IPR2021-01312/doc/1008).

• Prior Art Relied Upon: Babayoff (Patent 7,698,068).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was argued under a broader claim construction that does not require fluorescence. Petitioner asserted that Babayoff disclosed a 3D intraoral scanner that captured a color 3D representation of teeth by sequentially illuminating them with different colored lights (e.g., red, green, blue) and mapping the resulting 2D color image onto the 3D model. Petitioner contended that a POSITA would have understood that the color data in Babayoff’s system inherently provides information about cariogenic regions, as caries are known to cause tooth discoloration. Therefore, Babayoff’s system was already configured for displaying a digital representation of a cariogenic region (the color data) and a digital 3D representation of the tooth.
  • Motivation to Combine (Implicit Rationale): The argument was not a combination but an assertion that using Babayoff’s color scanning system for caries detection was an obvious, inherent application. The motivation was to use the available color information for its known diagnostic value in identifying discolored, cariogenic areas on a tooth, a straightforward application of the disclosed technology.
  • Expectation of Success: Success was expected as it merely involved interpreting the color data already produced by the Babayoff system, a technique well-established in the field of visual dental examinations.

Ground 3: Obviousness over Babayoff and Everett - Claims 1, 3, 5, 7-8, 20-21, 23, 25, 27-28, and 38 are obvious over Babayoff in view of [Everett](https://ai-lab.exparte.com/case/ptab/IPR2021-01312/doc/1009).

• Prior Art Relied Upon: Babayoff (Patent 7,698,068) and Everett (Patent 6,522,407).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon Babayoff’s 3D color scanner and proposed combining it with Everett. Everett taught an optical method for detecting caries by using polarized light, based on the principle that cariogenic regions depolarize incident light more than healthy tissue does. Petitioner argued that Babayoff’s system already used polarizers. The combination involved modifying Babayoff’s system to specifically measure the degree of depolarization as taught by Everett, thereby creating a system that records data for cariogenic regions.
  • Motivation to Combine: A POSITA would combine Babayoff and Everett to enhance the caries detection capabilities of Babayoff's scanner with a more sophisticated optical technique than simple color analysis. Everett’s method provided a quantitative way to detect demineralization, potentially identifying caries at earlier stages. This offered a clear advantage over relying solely on visual color differences.
  • Expectation of Success: A POSITA would expect success because Babayoff’s system already included the necessary core components, including polarizers. Implementing Everett’s teachings would involve straightforward modifications, such as adding a beamsplitter or rotating a polarizer to measure different polarization states, which were well-understood optical techniques.

4. Key Claim Construction Positions

• Petitioner highlighted a central dispute from parallel litigation regarding whether the claims require the detection of fluorescence.
• “Cariogenic region of the tooth”: Petitioner proposed a narrow construction requiring detection based on "emitted fluorescence." Patent Owner proposed a broader construction of "a region of the tooth with either tooth decay or characteristics... promoting tooth decay," not limited to fluorescence. Petitioner argued the claims were invalid even under the Patent Owner’s broader construction.
• “a second light source”: Similarly, Petitioner argued this should be construed as a source "used to excite a fluorescent material," while the Patent Owner argued for its plain and ordinary meaning. The petition proceeded by applying the broader construction.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) based on Fintiv factors was unwarranted.
• It was asserted that the parallel district court litigation was in its early stages, with no trial date set and discovery not yet begun. Petitioner noted its diligence in filing well before the statutory deadline and agreed not to pursue any instituted grounds in the parallel litigation, reducing concerns of duplicative efforts. The strength of the asserted grounds was also presented as a factor weighing heavily in favor of institution.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1, 3, 5, 7-8, 20-21, 23, 25, 27-28, and 38 of the ’333 patent as unpatentable.