Pipstek LLC v. Biolase Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Pipstek, LLC (Delaware)
  • Defendant: Biolase, Inc. (Delaware)
  • Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
• Case Identification: 1:23-cv-00011, D. Del., 01/04/2023
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has a continuous and systematic presence in the district, sells infringing products there, and commits acts of patent infringement in the district.
• Core Dispute: Plaintiff alleges that Defendant’s Waterlase products infringe patents related to methods for cleaning root canals using laser-induced photoacoustic waves.
• Technical Context: The technology concerns the use of "subablative" laser energy to create pressure waves in a fluid, which disintegrate and remove biological tissue from complex root canal systems without causing significant thermal damage to the tooth.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with written notice of infringement for both asserted patents on or about November 28, 2022, approximately five weeks before filing the lawsuit.

Case Timeline

Date	Event
2006-08-24	Earliest Priority Date for ’993 and ’239 Patents
2022-06-07	U.S. Patent No. 11,350,993 Issues
2022-08-30	U.S. Patent No. 11,426,239 Issues
2022-11-28	Defendant allegedly receives written notice of infringement
2023-01-04	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,350,993 - "Dental and Medical Treatments and Procedures", Issued June 7, 2022

The Invention Explained

• Problem Addressed: The patent describes the limitations of conventional root canal procedures, noting that mechanical files can weaken the tooth and fail to clean complex, branching lateral canals, while chemical treatments may be ineffective at penetrating the entire system (’993 Patent, col. 1:43-col. 2:29). It further identifies that prior art laser-based approaches often rely on high-energy ablation, which can cause destructive thermal damage to the tooth and surrounding tissue (’993 Patent, col. 2:42-60).
• The Patented Solution: The invention is a method that uses a pulsed laser with a specially designed fiber optic tip submerged in a fluid inside the root canal. Instead of using high heat to ablate tissue, the laser's energy creates rapid, localized heating in the fluid that generates a "photoacoustic" pressure wave (’993 Patent, col. 7:26-44). These pressure waves propagate through the fluid to disintegrate and dislodge pulp tissue throughout the main and lateral canals without generating significant heat, thereby avoiding thermal damage to the dentin (’993 Patent, col. 12:28-46).
• Technical Importance: This "subablative" photoacoustic approach provided a method to clean intricate root canal anatomies more thoroughly and less invasively than was possible with traditional files or high-energy ablative lasers (’993 Patent, col. 3:7-14).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶13).
• Claim 1 is a method for cleaning a root canal, the essential elements of which include:
  • Performing a first treatment cycle that involves providing an optical fiber with a "tapered tip" and specific cladding geometry, submerging it in a "first treatment liquid," and operating an "ErCrYSGG laser source" at specified power and pulse duration parameters.
  • Directing the laser beam "laterally outwardly" into the liquid to generate "photoacoustic waves" sufficient to clean the canal and remove material.
  • Performing a second treatment cycle with a "second treatment liquid" that repeats the laser operation steps.
• The complaint does not explicitly reserve the right to assert dependent claims, though this may be raised later in the litigation.

---

U.S. Patent No. 11,426,239 - "Dental and Medical Treatments and Procedures", Issued August 30, 2022

The Invention Explained

• Problem Addressed: The '239 Patent addresses the same technical problems as the '993 Patent: the inability of conventional endodontic files and ablative lasers to effectively and safely clean the entire root canal system, including hard-to-reach lateral canals (’239 Patent, col. 1:43-col. 2:67).
• The Patented Solution: The solution is again a method using a pulsed laser to generate photoacoustic waves within a treatment liquid to disintegrate tissue. This patent similarly focuses on achieving this cleaning effect through pressure waves rather than destructive thermal energy, thereby preserving the tooth's structure (’239 Patent, col. 7:26-44, col. 12:28-46).
• Technical Importance: As with the '993 Patent, this technology represents a minimally invasive approach to endodontic treatment designed to improve cleaning efficacy and reduce the risk of treatment failure associated with prior methods (’239 Patent, col. 3:7-14).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶21).
• Claim 1 of the '239 Patent is a method for cleaning a root canal, the essential elements of which include:
  • Delivering a treatment liquid into the root canal.
  • Inserting the tip of an optical fiber, where the tip is a "conical tip that emits at least a portion of laser light laterally outwardly."
  • Operating a laser source at a power level of at least 0.5 W and a wavelength of at least 1500 nm.
  • Pulsing the laser light and directing it "laterally outwardly" to create "photoacoustic waves" with sufficient vibrational energy to remove organic material from a wall of the root canal.
  • Withdrawing the tip from the root canal.
• The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

• The complaint identifies "Waterlase products" as the accused instrumentalities (Compl. ¶13, ¶21).

Functionality and Market Context

• The complaint alleges that the accused Waterlase products are laser systems marketed, sold, and offered for sale by Defendant for use in dental procedures (Compl. ¶13, ¶21). The core functionality at issue is the use of these laser systems by end-users, such as dentists, to perform root canal treatments. The complaint alleges that Defendant provides instructions, literature, and information on its webpages that direct customers and end-users to operate the Waterlase products in a manner that infringes the asserted patents (Compl. ¶13, ¶21).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint. The complaint references exemplary claim charts as Exhibits 3 and 4, but these exhibits are not included in the filing. The infringement theory is therefore summarized in prose based on the complaint's narrative allegations.

For both the ’993 Patent and the ’239 Patent, the complaint alleges that Defendant induces and contributes to the infringement of at least method Claim 1 of each patent (Compl. ¶13, ¶14, ¶21, ¶22). The theory of infringement is that end-users of Defendant's Waterlase products directly infringe the method claims by performing root canal procedures as instructed by Defendant. The complaint alleges that Defendant's marketing materials, user manuals, and webpages (referenced as Exhibits 5-9) instruct users to perform the steps of the claimed methods, including using the laser system with a fluid to clean root canals (Compl. ¶13, ¶21).

• Identified Points of Contention:
  • Technical Questions: A primary technical question will be whether the accused Waterlase products, when operated according to Defendant's instructions, actually generate "photoacoustic waves" as that term is used in the patents, or if they operate via a different physical mechanism, such as thermal ablation. The patents distinguish their "subablative" invention from prior art ablative lasers, which relied on high heat (’993 Patent, col. 2:42-53). Evidence will be required to show that the accused products meet the specific power, pulse, and temperature-related limitations of the claims (e.g., operating without "thermally damaging the dentin").
  • Scope Questions: Do the tips supplied with the Waterlase products meet the "tapered tip" and "conical tip" limitations of the claims? The patents describe this tip geometry as a key feature for generating a more effective, laterally-directed photoacoustic wave (’993 Patent, col. 8:6-11). The infringement analysis will depend on the physical characteristics of the accused tips and how they compare to the claims and the patent's description.

V. Key Claim Terms for Construction

• The Term: "photoacoustic waves"

• Context and Importance: This term describes the core physical mechanism of the invention and is central to distinguishing the claimed method from prior art thermal/ablative techniques. The infringement and validity analyses will hinge on whether the energy produced by the accused devices, and the prior art, falls within the scope of this term.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes the effect as sound or pressure waves generated when laser energy causes rapid, local heating and expansion of fluid molecules (’993 Patent, col. 7:26-34). This could support a reading that encompasses any pressure wave created by laser-fluid interaction.
  • Evidence for a Narrower Interpretation: The specification repeatedly qualifies the invention as "subablative" and emphasizes that it works "without generation of any significant heat" and avoids elevating the tooth's temperature by more than about 5° C. (’993 Patent, Abstract; col. 21:51-55). This extensive distinction from thermal effects could support a narrower construction that excludes processes where heat and ablation are significant or dominant effects.

• The Term: "tapered tip" / "conical tip"

• Context and Importance: This structural limitation appears in the independent claims of both patents and is described in the specification as important for achieving the desired lateral energy dispersion. Practitioners may focus on this term because infringement will require a direct structural mapping of the accused device tips onto this language.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification describes a wide range of possible geometries, including a taper angle between 10 and 90 degrees, and notes the tip may be "beveled" (’993 Patent, col. 6:58-60). This could support a broad definition covering various non-flat tip shapes.
  • Evidence for a Narrower Interpretation: The specification attributes a specific function to the taper: to disperse laser energy "laterally outwardly" and create a larger, "omnidirectional" wave, in contrast to a standard tip that directs energy linearly (’993 Patent, col. 9:11-25; col. 11:51-64). This functional language may support a narrower construction limited to tips that achieve this specific wave propagation pattern.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is based on Defendant allegedly providing marketing materials, instructions, and webpages that knowingly instruct and encourage end-users to perform the patented methods with the Waterlase products (Compl. ¶13, ¶21). Contributory infringement is based on allegations that the Waterlase products are a material part of the invention, are not staple articles of commerce, and are known by Defendant to be especially adapted for infringing use (Compl. ¶14, ¶22).
• Willful Infringement: The complaint alleges willful infringement based on Defendant’s continued infringing activities after receiving written notice of the patents on or about November 28, 2022. This establishes a claim of pre-suit knowledge (Compl. ¶16, ¶24).

VII. Analyst’s Conclusion: Key Questions for the Case

• A central issue will be one of technical operation: does the accused Waterlase system, when used as instructed, function primarily via the "subablative" generation of photoacoustic waves as claimed, or does it rely on the thermal, ablative effects that the patents position themselves against? The case will likely involve competing expert testimony on the physics of the laser-tissue interaction.
• A key legal question will be one of claim scope: can the term "photoacoustic waves," as defined in the context of a "subablative" process that avoids significant heat, be construed to read on the operation of the accused devices? The court's interpretation of this and other terms like "tapered tip" will be dispositive for infringement.
• A critical factual question for indirect infringement will be intent: assuming direct infringement by dentists is established, what specific evidence shows that Biolase's instructions and marketing materials actively encouraged performing every step of the claimed methods, thereby demonstrating the specific intent required for inducement?