DCT
1:24-cv-00507
Smart Denture Conversions LLC v. Straumann USA LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Smart Denture Conversions, LLC (North Carolina)
- Defendant: Straumann USA, LLC (Delaware)
- Plaintiff’s Counsel: Richards, Layton & Finger, P.A.; Smith, Anderson, Blount, Dorsett, Mitchell & Jernigan, LLP
- Case Identification: 1:24-cv-00507, D. Del., 04/23/2024
- Venue Allegations: Venue is asserted in the District of Delaware on the basis that Defendant is a Delaware limited liability company and therefore resides in the district.
- Core Dispute: Plaintiff alleges that Defendant’s NeoConvertTM system for converting removable dentures into fixed prostheses infringes a patent related to temporary screw and coping systems used in dental implant procedures.
- Technical Context: The technology concerns systems for attaching dental prostheses to implants, specifically aiming to improve the efficiency and precision of the clinical process where a coping is bonded to a prosthesis.
- Key Procedural History: The complaint does not mention any prior litigation, inter partes review proceedings, or licensing history related to the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2018-10-09 | U.S. Patent No. 11,937,992 Earliest Priority Date |
| 2024-03-26 | U.S. Patent No. 11,937,992 Issued |
| 2024-04-23 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,937,992 - “Screw-Attached Pick-Up Dental Coping System and Methods,” issued March 26, 2024
The Invention Explained
- Problem Addressed: The patent’s background section describes challenges with conventional methods for attaching dental prostheses to implants. Systems requiring "open-tray" impressions to access and unscrew temporary fasteners are described as potentially causing patient discomfort and requiring large, weakening holes to be drilled in the denture (’992 Patent, col. 3:6-14). Other systems, such as snap-on types, may be more expensive or lack the precision of screw-retained systems (’992 Patent, col. 2:36-45).
- The Patented Solution: The invention is a temporary alignment system that facilitates a "closed-tray" pick-up process. It employs a temporary fastener, which may consist of a threaded post and a separable cap, to hold a dental coping against an implant abutment (’992 Patent, col. 4:38-44). After a prosthesis is positioned over the coping and bonded to it, the prosthesis can be removed with a pulling (axial) force. This force is designed to cause the cap to separate from the post, releasing the prosthesis and embedded coping while leaving the post threaded in the abutment for later removal (’992 Patent, col. 4:44-51; Abstract). This process aims to simplify the procedure without compromising the alignment accuracy.
- Technical Importance: The described technology seeks to combine the alignment precision of traditional screw-retained systems with the procedural simplicity and improved patient comfort of a closed-tray impression technique (’992 Patent, col. 4:30-35).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 (Compl. ¶33).
- The essential elements of independent claim 1 include:
- An implant abutment with threads.
- A definitive screw with a head and a threaded post portion.
- A coping with an aperture sized to allow the definitive screw's post to pass through but not its head.
- A temporary screw comprising a proximal head portion and a distal shaft portion with threads in a pattern "shaped differently" from the definitive screw's threads.
- A functional requirement that rotating the temporary screw engages the abutment threads to hold the coping in place, and a subsequent axial "pick-up" force releases both the coping and the temporary screw from the abutment.
III. The Accused Instrumentality
Product Identification
- The accused instrumentality is the Straumann NeoConvertTM system (Compl. ¶23).
Functionality and Market Context
- The complaint alleges the NeoConvertTM system is used to convert removable dentures into fixed prostheses (Compl. ¶23). The alleged process involves using temporary screws to connect copings to abutments, setting the denture over the copings with bonding material, removing the denture to "pick up" the bonded copings, drilling clearance holes, and finally using definitive screws to fix the denture to the abutments (Compl. ¶25). The complaint alleges that Straumann competes directly with the plaintiff, SDC, and that no other manufacturer offers a system that converts dentures into permanent prostheses as quickly (Compl. ¶28). A cross-sectional view provided in the complaint illustrates the alleged interaction between the accused temporary screw, coping, and abutment (Compl. p. 10).
IV. Analysis of Infringement Allegations
’992 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| an implant abutment having threads | The NeoConvert™ system includes threaded abutment options, including the “GM Mini Conical Abutment,” shown in an image from product materials. This image depicts a component with external threads. | ¶35 | col. 12:50-51 |
| a definitive screw having ... a distal post portion having threads configured to engage the threads of the implant abutment | The system includes a definitive screw, the “Neo Mini Conical Abutment Coping Screw 4.1,” which has threads on its distal post portion. An image of this screw is provided. | ¶36 | col. 15:25-30 |
| a coping having ... an aperture wherein the aperture is larger than the distal post portion of the definitive screw and smaller than the proximal head end | The system includes coping options whose apertures are allegedly sized to allow the definitive screw's threaded post to pass through but not its head, consistent with the claim. Images of the "Mini Conical Abutment Coping" are provided. | ¶37 | col. 12:50-52 |
| a temporary screw ... with threads in a pattern that is shaped differently from a pattern of the threads of the definitive screw | The NeoConvertTM system includes a temporary screw, the “Pin Capture NeoConvert,” which allegedly has threads shaped differently from those of the definitive screw. An image of this temporary screw is included. | ¶38 | col. 25:52-55 |
| wherein an axial force in a proximal direction from pick-up processing releases the coping and the temporary screw from the implant abutment | The complaint alleges that the interaction of the accused "Pin Capture NeoConvert" screw, abutments, and copings satisfies this limitation, allowing the denture and copings to be removed. A cross-sectional view illustrates the alleged interaction (Compl. p. 10). | ¶39 | col. 26:1-60 |
- Identified Points of Contention:
- Technical Question: Claim 1 requires the temporary screw's threads to have a "pattern that is shaped differently" from the definitive screw's threads. The complaint provides images of the two accused screws, but whether their thread patterns are meaningfully "different" in a manner that aligns with the patent's teachings may become a central factual dispute requiring expert testimony.
- Scope Question: The final limitation of Claim 1 states that an axial force "releases the coping and the temporary screw from the implant abutment." The patent's primary embodiment, however, describes a temporary screw with a separable cap, where the cap is released with the coping, but the threaded post remains in the abutment for later removal (’992 Patent, col. 13:42-50). This raises the question of whether "releases the...temporary screw" requires complete physical detachment of the entire screw assembly from the abutment, or if the functional release of the coping-retaining portion of the screw is sufficient to meet the limitation.
V. Key Claim Terms for Construction
The Term: "threads in a pattern that is shaped differently from a pattern of the threads of the definitive screw"
- Context and Importance: This term appears to be a point of novelty intended to distinguish the temporary screw from the definitive one. The interpretation of "shaped differently" will be critical, as infringement may turn on whether any distinction between the accused screws' threads is sufficient to meet this limitation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The plain meaning of "shaped differently" is broad and could encompass any non-identical geometric property, including thread pitch, flank angle, or overall profile. The patent specification contemplates various alternative thread designs, such as asymmetric threads, which would fall under this definition (’992 Patent, col. 23:14-23).
- Evidence for a Narrower Interpretation: A party could argue that the term implies a functional difference, not merely an incidental one. The patent also notes that the temporary fastener may engage the same screw threads of the abutment used for the definitive attachment (’992 Patent, col. 4:59-62), which might be used to argue that the "different" shape cannot be one that would prevent this engagement.
The Term: "releases the coping and the temporary screw from the implant abutment"
- Context and Importance: This term defines the invention's core release mechanism. The dispute will likely center on what constitutes a "release" of the "temporary screw." Practitioners may focus on this term because of a potential tension between the claim language and the embodiments described in the specification.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A proponent could argue that "releases" should be interpreted functionally. From this perspective, the "temporary screw" is "released" when its function of holding the coping to the abutment is overcome, allowing the prosthesis to be removed, even if a component of the screw remains physically attached to the abutment.
- Evidence for a Narrower Interpretation: The phrase "releases...from the implant abutment" could be interpreted to require complete physical separation. The patent's main embodiment shows the threaded post of the temporary screw remaining engaged in the abutment after the cap and coping are removed (’992 Patent, FIG. 6). This could support an argument that the embodiment itself does not practice a literal reading of the claim, potentially creating prosecution history estoppel or claim construction issues.
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is based on allegations that Straumann encourages, instructs, and trains dental professionals to use the accused system through advertising, training sessions, and informational brochures (Compl. ¶40). Contributory infringement is alleged on the basis that the temporary screw component (the "Pin Capture NeoConvert") is a material part of the invention and not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶40-41).
- Willful Infringement: The complaint alleges that Straumann's infringement is "knowing, intentional, and willful, at least as of the date this Complaint was filed" (Compl. ¶42). This asserts willfulness based on knowledge gained from the filing of the lawsuit itself, seeking enhanced damages for any post-filing infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
This case presents focused questions of both technical fact and legal interpretation. The outcome may depend on the court's resolution of the following:
- A key evidentiary question will be one of technical comparison: do the threads of the accused NeoConvert™ temporary screw have a "pattern that is shaped differently" from the threads of its corresponding definitive screw? The resolution will likely depend on expert analysis of the physical products.
- A core issue will be one of definitional scope: can the phrase "releases the...temporary screw from the implant abutment" be construed to cover a mechanism where only a portion of the temporary screw separates, while its threaded post remains engaged in the abutment, as depicted in the patent's own primary embodiment? The court’s interpretation of this claim language will be critical to the infringement analysis.