IP Law Daily, PATENT—D.N.M.: Patents involving hi-tech endodontic files are valid; infringement issues remain, (Jun 25, 2020)

By David Yucht, J.D.

An issue also existed as to whether a dental device company was "willfully blind" to the existence of its competitor’s previously registered patents.

A federal judge in New Mexico denied motions for summary judgment of noninfringement of patents directed to dental instruments filed by defendants Edge Endo, LLC and US Endodontics, LLC (together Edge) in an action brought by plaintiffs Dentsply Sirona Inc. and Tulsa Dental Products LLC (together Dentsply). The court also found that disputed material facts precluded determining whether any infringement by the defendants was willful. Additionally, the court granted Dentsply’s motion for partial summary judgment establishing that the term "a shank configured for attachment to a motor" must be applied according to its plain meaning and Endo may not assert a non-infringement defense as to that claim element (Dentsply Sirona Inc. v. Edge Endo, LLC, June 23, 2020, Bataillon, J.).

Dentsply Sirona Inc. has sold its ProTaper Next endodontic files since January 2013. Dentsply complained that Edge Endos, LLC promoted a product known as Edge Taper Encore which Dentsply alleged was identical to Dentsply’s product. Dentsply asserted that in promoting the Edge Taper Encore, Edge infringed four patents which covered advances in the technology used in endodontic files: "Swaggering Endodontic Instruments," U.S. Patent No. 8,932,056 (the ’056 patent), "Endodontic Instruments with Offset Centers of Mass," U.S. Patent No. 9,351,803 (the ’803 patent), "Swaggering Endodontic Instruments," U.S. Patent No. 8,882,504 (the ’504 patent), and "Instruments for Drilling Dental Root Canals," U.S. Patent No. 9,801,696 (the ’696 patent). Dentsply sued for infringement. Edge and Dentsply both moved for summary judgment.

Summary judgment of non-infringement of the ’696 patent. The court denied Endo’s motion for summary judgment of non-infringement of the ’696 patent. Dentsply contended that Edge's Edge Taper Encore X1 endodontic file infringed claims of the ’696 patent either literally or under the doctrine of equivalents. Edge’s ’696 patent related to an instrument for drilling dental root canals. A key element of its competitor’s pre-existing patented device is that its center of mass is located on its axis of rotation. The court noted that to prevail on its claim of literal infringement, Dentsply needed to show that every cross-section in the "first portion" claimed in the ‘696 patent had its center of mass coinciding with the axis of rotation. Dentsply argued that there was sufficient evidence of literal infringement, based on its expert’s opinion, admissions of Edge personnel and physical samples.

Additionally, Dentsply argued that the Edge Taper Encore was functionally equivalent to its Pro Taper Next. The court found that there was substantial evidence that would permit a jury to determine that Edge Taper Encore X1 had a first portion that was centered on the axis of rotation, and that it therefore literally infringed Dentsply claims, or in the alternative, it infringed under the doctrine of equivalents. There was significant disagreement as to the size of the measured deviations from the axis of rotation of each company’s product. Dentsply contended that it was up to a jury to determine how close was close enough to be considered infringing. Regarding the doctrine of equivalents, Dentsply argued that a jury could reasonably conclude that a portion near the tip of the Edge Taper Encore X1 was supposed to be centered and it infringed under the doctrine of equivalents because the deviations between the two files were insubstantial and did not materially affect performance.

Willful infringement. The court also denied Endo’s motion for summary judgment concerning willfulness. To establish willful infringement, it must be shown that the alleged infringer had pre-suit knowledge of the asserted patents. Enhanced damages due to willful infringement may be given for egregious cases. Endo contended there was no evidence of knowledge of any patents-in-suit prior to the filing of this lawsuit. The court found sufficient facts at issue to allow this claim to go to trial. There was an issue concerning when Endo knew or should have known about the pre-existing patent. Also at issue was whether Endo was "willfully blind" to the existence of these patents and whether it continued to infringe these patents during the pendency of this lawsuit.

Dentsply motion for partial summary judgment. Dentsply’s motion for partial summary judgment was granted as to the term "a shank configured for attachment to a motor," and Endo was precluded from asserting a non-infringement defense as to that claim element. The court noted that by reading the word "directly" into the claim element: "a shank configured for attachment to a motor," Endo was proposing a new claim construction which had not been previously raised. The court agreed with Dentsply that Endo failed to provide evidence that this term should be construed in a manner contrary to its ordinary meaning, or contrary to the patent specifications. Consequently, the court granted Dentsply’s motion for summary judgment that the Edge Taper Encore infringed the asserted claims of the ’504, ’056 and ’803 patents.

Dentsply patent claims not invalid. The court granted Dentsply’s motion for partial summary judgment that various patent claims were not invalid. The court found that Endo’s defenses were legally deficient and that reasonable jurors could not find invalidity by clear and convincing evidence. Dentsply’s claims were not obvious nor would a person of ordinary skill in the art have had a reasonable expectation of success in creating them. In addition, Endo offered no motivation as to why a person would combine these prior art teachings to arrive at the claimed invention. Endo’s expert witness admitted that he had not mapped out how this could be done and had not personally ever made these modifications. None of the references he relied on explained how his proposed method could be used to produce a file like Dentsply’s product.

The court also found that the evidence regarding combining these multiple designs into a single instrument was not sufficiently explained by Endo. Endo’s reasons for its combination were nonexistent. "Hindsight reconstruction" was insufficient.

This case is No. 1:17-cv-01041-JFB-SCY.

Attorneys: Eric D. Blatt (Rothwell Figg Ernst & Manbeck PC) for Dentsply Sirona Inc. and Tulsa Dental Products LLC d/b/a Dentsply Sirona Endodontics. Abhishek Bapna (Patterson Belknap Webb & Tyler LLP) for Edge Endo, LLC and Us Endodontics LLC.

Companies: Dentsply Sirona Inc.; Tulsa Dental Products LLC d/b/a Dentsply Sirona Endodontics; Edge Endo; LLC; Us Endodontics LLC

Cases: Patent GCNNews NewMexicoNews