PTAB

IPR2016-00481

3Shape Medical AS v. Sirona Dental Systems GmbH

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Producing a Drill Assistance Device for a Tooth Implant
  • Brief Description: The ’006 patent discloses a method for creating a precise drill assistance device, or surgical template, for dental implants. The method involves taking an X-ray of a patient's jaw, performing a three-dimensional (3D) optical measurement of the visible tooth and jaw surfaces, correlating the two data sets, and using the combined information to determine the optimal position for a pilot hole in the drill template.

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness over Mushabac - Claims 1-5, 9, and 10 are unpatentable under 35 U.S.C. §§ 102/103 over Mushabac.

  • Prior Art Relied Upon: Mushabac (Patent 5,562,448).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Mushabac taught every element of the challenged claims. Mushabac disclosed a method for facilitating dental diagnosis and treatment by generating digitized X-ray data and digitized surface data (from optical or probe-based measurements). It explicitly taught correlating these data sets to produce a composite image showing both internal and external structures. Based on this composite image, Mushabac determined an optimal position for a bore hole and disclosed using a block of acrylic material with a matching hole as a surgical template to guide the drill. For dependent claims, Mushabac taught using computer tomography, identifying occlusal surfaces, using ball-shaped markers for correlation, and fabricating the template from a dimension-stable material.
    • Motivation to Combine (for §103 grounds): As an alternative to anticipation, Petitioner asserted that all claim elements were present in Mushabac, and it would have been obvious to a person of ordinary skill in the art (POSITA) to combine its teachings to arrive at the claimed invention.

Ground 2: Anticipation/Obviousness over Poirier - Claims 1-5, 9, and 10 are unpatentable under 35 U.S.C. §§ 102/103 over Poirier.

  • Prior Art Relied Upon: Poirier (Patent 5,725,376).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Poirier, like Mushabac, independently taught the entire claimed method. Poirier disclosed manufacturing a dental implant drill guide by obtaining a medical image (X-ray) of the jawbone and imaging the gum surface to create a 3D computer graphics model. The method involved integrating all images, referencing them to one another, and allowing a surgeon to select the optimal implant drill hole positions using the model. Poirier further disclosed fabricating the drill template from a dimension-stable material using a CNC device and using radio-opaque spheres as markers to correlate the different image data sets.
    • Motivation to Combine (for §103 grounds): In the alternative to anticipation, Petitioner argued that any minor differences between Poirier's disclosures and the claim limitations would have been obvious modifications for a POSITA.

Ground 3: Obviousness over Bannuscher in view of Massen - Claims 1-5 are obvious over Bannuscher in view of Massen.

  • Prior Art Relied Upon: Bannuscher (German Application DE 195 10 294) and Massen (Patent 5,372,502).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Bannuscher provided the primary framework for the claimed method. Bannuscher taught preparing a surgical template by combining X-ray diagnostics with a 3D geometric model of the mouth and jaw. However, Bannuscher created its 3D model from physical impressions and plaster casts. Massen supplied the missing element by teaching a direct 3D optical measuring probe for surveying teeth to obtain digital data for a 3D model without needing a physical impression.
    • Motivation to Combine: A POSITA would combine these references to improve the accuracy and efficiency of Bannuscher's method. Replacing Bannuscher’s manual, multi-step process of creating a plaster model with Massen’s direct, automated optical scanning was a predictable solution to create a more precise 3D model for surgical planning.
    • Expectation of Success: Because both references addressed the same problem of creating 3D dental models for surgical planning, a POSITA would have had a high expectation of success in integrating Massen’s superior data acquisition technique into Bannuscher’s established planning workflow.

  • Additional Grounds: Petitioner asserted that claims 6-8 are obvious over the primary references (Poirier, Mushabac, or Bannuscher/Massen) in view of secondary references including Verstreken, Truppe, or Weese. These secondary references were cited to teach the conversion of 3D optical data into a "pseudo-X-ray picture" and superimposing it on the actual X-ray image from multiple directions, as required by the dependent claims.

4. Key Claim Construction Positions

  • Petitioner argued that the term "pseudo-X-ray picture" in claims 6-8 had no accepted meaning in the art. For the purpose of the IPR, Petitioner proposed that the term should be construed as "a representation of measured data records of the three-dimensional optical measuring that can be superimposed with an X-ray picture." This construction was critical to mapping the teachings of references like Verstreken, which disclosed converting 3D data into 2D reslices for superimposition, onto the claim language.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-10 of the ’006 patent as unpatentable.