US 10646419

I'll search for authoritative information on US patent 10646419, including USPTO records and any CAFC 2026 docket activity.

Let me search specifically for CAFC 2026 appellate docket activity involving this patent.

Analysis: US Patent No. 10,646,419 — "Peroxide Gel Compositions"

Bibliographic Data (literal identifiers as found)

Source: https://patents.google.com/patent/US10646419/en ; https://pubchem.ncbi.nlm.nih.gov/patent/US-10646419-B2

Prosecution/administrative notes: A certificate of correction was recorded July 5, 2022; a 4th-year maintenance fee (small entity) was paid Feb. 26, 2024 with a late-payment surcharge. This is a continuation of US 14/710,416 (issued as US 9,785,036 B2), which was itself a continuation of US 12/329,582 (US 9,295,619 B2), a continuation-in-part of US 11/307,463 (US 2007/0183987 A1). Numerous later continuations issued, including US 10,603,259, US 11,219,582, US 11,826,444, and US 11,826,445.

Abstract (verbatim)

"A dental bleaching device may include a backing material made of a polymeric wax mixture, and a dental composition in contact with the backing material. The dental composition may include a thickening agent and a peroxide bleaching agent. The dental composition may be a gelatinous compound having physical deformation properties that allow the dental composition to bend and conform to a shape of a container into which the dental composition is placed, but the dental composition will not merge into a second piece of the dental composition when placed in contact with the second piece."

Independent Claims — Plain-Language Overview

The patent has three independent claims: 1, 16, and 28.

Claim 1 — Basic dried strip device. Covers a dental bleaching device with two required parts:

• A flexible, planar strip of backing material having two flat sides;
• A dental composition on one flat side, covering substantially all of that side solely with the composition.

The composition (as applied) must contain: a peroxide bleaching agent; water as the first solvent; and a thickening agent that is poly(2-ethyl-2-oxazoline) and/or polyvinylpyrrolidone (PVP). The composition is dried after application and must be gelatinous and visco-elastic at four defined stages: (a) after application and drying, (b) during room-temperature storage up to six months in a package, (c) after removal from the package, and (d) while flexibly positioned on teeth. It must also be able to bend and conform to adjacent teeth while remaining on the strip during use, and be adhesive enough to adhere to adjacent teeth once placed.

Claim 16 — Two-solvent variant with "deform under its own weight." Builds on claim 1 by requiring both a first solvent (water) and a second solvent that is an organic solvent, the same thickening-agent limitations, all four gelatinous/visco-elastic stages, plus an added functional limitation: the composition must "deform under its own weight if removed from the strip of backing material" (in addition to conforming, remaining on the strip, and adhering to teeth).

Claim 28 — Packaged-device variant. Same technical substance as claim 16 (dual solvents, PVP/PEOX thickening agent, dried, gelatinous/visco-elastic, deform-under-own-weight, adherent), but expressly recites that the device is "packaged in a package," and that the six-month room-temperature storage stage occurs inside that package. Effectively claim 16 recast in packaged-product form.

Representative dependent limitations to note: backing material being a polymeric wax mixture (claims 2, 29 — described in the specification as PARAFILM), polyolefins + paraffin wax (claim 3); organic solvent selected from ethanol, PEG, polypropylene glycol, glycerin, propylene glycol (claims 4, 8, 18, 21, 32); relative weight ratios between thickening agent, water, and organic solvent (claims 5–10, 19–23, 31–34); thickening agent at ~33–50 wt% (claims 13, 26, 35); peroxide at ~11–27 wt% or up to ~50 wt% (claims 14, 15, 27, 35); viscosity 1,000–200,000 cPs (claim 17); two homogeneous layers (claim 30).

Technical Core

The asserted point of novelty is substituting poly(2-ethyl-2-oxazoline) (and, less preferably, PVP) as the thickener, which the specification asserts survives concentrated hydrogen peroxide (up to 50%) better than prior thickeners such as CARBOPOL, silica, PVP, and polyethylene glycols — purportedly staying a gel for six months at room temperature, thereby allowing pure H₂O₂ at concentrations where the prior art used adducts like carbamide peroxide.

Litigation Status (searched; secondary aggregators)

This patent has been actively asserted by CAO Group. Dockets I could identify:

• CAO Group, Inc. v. The Individuals… (Schedule A), 1:24-cv-01211 (N.D. Ill.) — filed Feb. 12, 2024; default judgment entered in related N.D. Ill. case 1:24-cv-05129 (treble damages ~$1.65M), and per PatSnap a separate schedule-A order at $1,518,750 per defaulting defendant.
• Ranir LLC v. CAO Group, 2:24-cv-00498 (D. Utah) — declaratory judgment of non-infringement/invalidity (Ranir as DJ plaintiff).
• CAO Group v. Walmart, 2:24-cv-00175 (D. Utah) — dismissed with prejudice by stipulation.
• CAO Group, Inc. v. GuruNanda, LLC, 8:25-cv-02074 (C.D. Cal.) — filed Sept. 12, 2025.
• CAO Group, Inc. v. Ivoclar Vivadent, Inc., 1:25-cv-01430 (D. Del.) — filed Nov. 24, 2025.

Sources: https://npe.law.stanford.edu/patent/10646419 ; https://npe.law.stanford.edu/case/[308900](/patent/308900) ; https://www.patsnap.com/de/resources/blog/litigation/cao-group-v-walmart-teeth-whitening-patent-dispute-patsnap/ ; https://portal.unifiedpatents.com/litigation/Utah%20District%20Court/case/2%3A24-cv-00498

CAFC 2026 Docket — Specific Finding

I did not find any Court of Appeals for the Federal Circuit docket (2024, 2025, or 2026) naming US 10,646,419 specifically as the patent on appeal. The CAFC/Federal Circuit material that surfaced in 2026 concerns a different entity and different patents: CAO Lighting, Inc. v. Wolfspeed, Inc. (appeal no. 24-1222; Supreme Court No. 25-1068, cert. denied May 18, 2026), which involved U.S. Patent Nos. 6,465,961 and 6,634,770 (LED lighting) — not US 10,646,419. I flag this so it is not conflated with the instant patent. My search was limited to web-accessible sources (Google Patents, PubChem, Unified Patents, Stanford NPE database, PatSnap, news aggregators) and did not include a direct PACER/CAFC docket query, so I cannot rule out an unindexed or very recent appeal.

Uncertainties / Caveats

1. Date discrepancies between sources. The authoritative patent text lists filing June 20, 2017 and grant May 12, 2020 and priority Feb. 8, 2006. Unified Patents lists these as 2017-06-19, 2020-05-11, and priority 2006-02-07 (each one day earlier). I have preferred the patent text as instructed; treat the one-day offsets as probable aggregator artifacts.
2. Expiration. Google Patents lists an "anticipated expiration" of Feb. 8, 2026 (i.e., the 20-year term running from the 2006 priority filing under 35 U.S.C. § 154, pre-URAA-style continuation chains). If that date is correct and today's date is April 26, 2026, the patent would already be past its nominal term — consistent with the "Expired – Lifetime" status, though there is a potential term-adjustment (PTA) question I could not verify from the sources retrieved.
3. Litigation details (case names, judgments, damages figures) come from third-party aggregators rather than primary PACER records and should be independently confirmed.
4. The certificate of correction (July 5, 2022) content is not reflected in the retrieved text; the claim language I summarized is from the published patent as indexed.

Primary source for bibliographic and claim text: https://patents.google.com/patent/US10646419/en (and Justia mirror: https://patents.justia.com/patent/10646419).

I'll research litigation involving US patent 10646419. Let me run several targeted searches.

I have strong initial results. Let me confirm details and outcomes for each case and check for any PTAB proceedings.

Summary

Yes — US 10,646,419 ("Peroxide gel compositions," inventor Steven D. Jensen; owner/assignee CAO Group, Inc., originally Cao Group LLC) has been the subject of multiple U.S. district court lawsuits. It is one member of a five-patent "Peroxide Gel / Sheer White!" dental-whitening strip family (along with US 10,603,259; 11,219,582; 11,826,444; 11,826,445) that CAO Group has asserted together in most of these cases. All known suits have CAO Group as plaintiff/enforcer, except one declaratory-judgment action brought against CAO.

The '419 patent had an anticipated expiration of 2026-02-08 (20 years from the 2006-02-08 priority date), so as of today (2026-04-26) it is expired; any still-pending matters would now be limited to past damages.

Google Patents itself flags this family as having litigation and lists seven case links: Utah 2:24-cv-00498 and 2:24-cv-00175; N.D. Ill. 1:24-cv-05129, 1:24-cv-04903, and 1:24-cv-01211; D. Del. 1:25-cv-01430; and C.D. Cal. 8:25-cv-02074.

Known litigation involving US 10,646,419

Case-by-case notes

• 1:24-cv-01211 (N.D. Ill., Schedule A). The complaint asserted '259 (Count I), '419 (Count II), and '582 (Count III); default judgment motion filed May 23, 2024. See the complaint/Order PDF: https://storage.courtlistener.com/recap/gov.uscourts.ilnd.455246/gov.uscourts.ilnd.455246.70.0.pdf. The default-judgment order (PatSnap summary, sourced to PACER) awarded $500,000 reasonable royalty + $50,000 transaction costs per defaulting defendant, trebled to $1,518,750 per defendant, plus injunctive relief and third-party account freezes.

• 2:24-cv-00175 (D. Utah, CAO v. Walmart). Asserted '259, '419, '582, '444, '445. Voluntarily dismissed with prejudice. Verbatim dismissal stipulation quoted by PatSnap from PACER.

• 2:24-cv-00498 (D. Utah, Ranir v. CAO). A defensive DJ action triggered by CAO's 2023–2024 demand letters naming '259, '419, '582 and later '444, '445, and by CAO's suit against Ranir's customer Walmart. Ranir alleged its OCL film predated CAO's patents (invalidity) and that its two-step, no-drying process did not infringe (not "gelatinous, non-coalescent, visco-elastic"). Docket (Stanford/Lex Machina via dockets.justia.com) shows case closed.

• 1:25-cv-01430 (D. Del., CAO v. Ivoclar Vivadent) and 8:25-cv-02074 (C.D. Cal., CAO v. GuruNanda). Both recent; the Stanford NPE database (npe.law.stanford.edu) lists these as the ongoing '419-related suits. No publicly reported outcome yet.

PTAB / Federal Circuit

I found no IPR, PGR, or CBM proceeding and no Federal Circuit appeal specifically involving US 10,646,419 in the sources searched. (The CAO Group IPR/patent litigation appearing in searches — e.g., IPR2022-00847 — concerns CAO's separate LED patent 6,465,961, not '419. I could not exhaustively confirm the absence of any PTAB filing.)

Caveats

• Confirmed primarily via third-party litigation databases — Stanford NPE Litigation Database (https://npe.law.stanford.edu/patent/10646419), PatSnap litigation summaries sourced to PACER, Patexia, the Unified Patents portal (https://portal.unifiedpatents.com/patents/patent/US-10646419-B2), and CourtListener/archive.org copies of the complaints and orders. I did not independently pull each PACER docket, so filing dates, defendant counts, and statuses for the most recent (2025) cases should be re-verified against PACER.
• The Delaware case's patent list includes the identifier "10602259" exactly as reported by the database; I have not auto-corrected it (it may or may not be the '259 patent, US 10,603,259).
• Case No. 25-cv-14512 is reported only by non-U.S. seller-news sources; its docket number and the exact role of '419 are unverified, and I present it as provisional.
• No CAFC appeal for '419 was located.

Proceedings overview

Total AIA trial proceedings on file for US 10,646,419: 0 — the USPTO Open Data Portal returns no IPR, PGR, or CBM involving this patent, and targeted web searching surfaced no petition, institution decision, or Final Written Decision that the ODP may simply not have ingested yet. The breakdown is therefore: 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denials. Bottom line for a defendant: the patent has never been tested at the PTAB. Claims 1–35 all stand un-adjudicated by the Board, and the "hardened by IPR" narrative cuts the other way — this is an untested patent whose validity is being litigated for the first time in district court. That is a different posture from "claims canceled," and it means you cannot point a judge or the patent owner at any Board finding of unpatentability.

Verification note (no fabrication): The instructions ask for proceeding-by-proceeding detail. There is no such detail to give, because there are no proceedings. Below I supply (a) the confirming search record, (b) the closest analog — a district-court validity challenge that is not a PTAB proceeding — and (c) the patent owner's own PTAB history, which is a pattern signal. I did not invent proceeding numbers to fill the template.

Search record confirming the null result

• Source of truth — structured ODP block: "The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest." No proceeding number, petitioner, or status is listed.
• Google Patents litigation docket for US10646419B2 (https://patents.google.com/patent/US10646419B2/en): lists only district-court cases (D. Utah 2:24-cv-00498 and 2:24-cv-00175; N.D. Ill. 1:24-cv-05129 and 1:24-cv-04903; N.D. Ill. 1:24-cv-01211; D. Del. 1:25-cv-01430; C.D. Cal. 8:25-cv-02074). No "PTAB" or "IPR" entries.
• Web searches for 10646419 IPR, "10646419" PTAB, CAO Group peroxide gel IPR, and Unified Patents IPR Cao Group returned no AIA trial touching the '419. Note the search noise: results citing "the '464 Patent" (e.g., Bumble Trading LLC v. KinectUS LLC, IPR2021-00901) refer to U.S. Patent No. 9,584,464 — a mobile-device patent, a completely different document. Do not confuse them.
• Unified Patents portal (https://portal.unifiedpatents.com/patents/patent/US-[10646419](/patent/10646419)-B2) shows no IPR listings for this patent, consistent with "no defensive aggregator in the chain."

Uncertainty flag: I could not inspect PTAB E2E directly, and ODP ingest can lag. A petition filed in the last few months could be missing from all sources above. I rate the residual risk low, because this patent has been asserted in at least seven district-court actions over 2024–2025 without producing a single Board filing — a pattern that would be unusual if a serious IPR challenge were pending.

Closest analog (NOT a PTAB proceeding — district court) — CAO Group v. Schedule A Defendants, invalidity challenge

• Forum: N.D. Ill., lead case 1:24-cv-01211 (and related 1:24-cv-04903, 1:24-cv-05129)
• What happened: Defendants moved to vacate the preliminary injunction on invalidity/non-infringement grounds, arguing the accused whitening strips were "made within the scope of the Prior Arts," specifically U.S. Patent Nos. 5,891,453 and 5,894,017 (P&G). The court granted the motion to vacate the PI as to the Cheng defendant, reasoning that a product within the scope of prior art cannot infringe "unless the Patents-in-suit are anticipated by the Prior Arts."
• Why it matters (notwithstanding that it is not AIA): This is the only adjudicated validity-side win against the CAO whitening portfolio I located, and it leans on the same P&G Sagel-family references that appear on the face of the '419 and its siblings. Those references are therefore the natural IPR ground for anyone who still can file.
• Citation: https://storage.courtlistener.com/recap/gov.uscourts.ilnd.[455246](/patent/455246)/gov.uscourts.ilnd.455246.102.0.pdf

Pattern signal — the patent owner is a PTAB petitioner itself (on other patents)

CAO GROUP, INC., Petitioner v. THE PROCTER & GAMBLE COMPANY, Patent Owner — IPR2014-00796 (U.S. 5,989,569) and IPR2014-00798 (U.S. 7,122,199), both filed 2014-05-21. These are CAO attacking P&G's strip patents, not challenges to the '419. They establish that CAO understands PTAB practice and has been the aggressor, not the target. No follow-on proceeding against any CAO patent appears in the record.

Litigation posture (context only — these are not AIA proceedings)

Strategic summary

Claim status of US 10,646,419. No claim has been canceled, narrowed, or confirmed by the Board. The patent issued 2020-05-12 with 35 claims (independent claims 1, 16, and 28), and every one of them is UN-adjudicated at the PTAB. There is no FWD to cite, no certificate of cancellation, and no estoppel running against anyone. Independent claim 1 covers a flexible/planar backing strip carrying a dried, gelatinous, visco-elastic peroxide composition thickened by poly(2-ethyl-2-oxazoline) or PVP that remains adhesive to teeth; claims 16 and 28 add the "will deform under its own weight" and "packaged up to six months" limitations. The only prosecution-history narrowing is a certificate of correction entered 2022-07-05 — a clerical fix, not a substantive amendment.

Estoppel landscape — there is essentially none, but the § 315(b) clock is the real problem. Because no IPR was ever instituted, § 315(e)(2) estoppel does not bar any ground for any defendant. In principle every prior-art combination is on the table, including the P&G Sagel references (U.S. 5,891,453; 5,894,017; 6,045,811; 7,122,199) that appear on the '419's own face and that a N.D. Ill. court already credited against this portfolio. The practical constraint is 35 U.S.C. § 315(b): any defendant served with a complaint alleging infringement more than one year before filing its petition is time-barred. Most of the Schedule A defendants were served in 2024; Ivoclar Vivadent and GuruNanda in 2025; a newly served 2026 defendant has a fresh one-year window. Critically, the patent's anticipated expiration is 2026-02-08, which has now passed (today is 2026-09-28) — an IPR of an expired patent can still be filed but is largely moot for prospective relief, and the owner's remaining leverage is past damages only (subject to the six-year § 286 lookback). Any defendant weighing an IPR should run the math on § 315(b) and on whether invalidity is better run as a district-court defense in the co-pending litigation.

Pattern signals. (1) No defensive aggregator — Unified Patents shows no filings on the '419, so this patent is not in a defensive-funded campaign. (2) The patent owner is a serial plaintiff, not a troll in the classic sense: CAO Group makes the accused-competitor product ("Sheer White!" whitening strips, distributed via Henry Schein), sued in the forum and against the parties listed above, and won a $1,650,000 trebled default judgment. (3) The portfolio is a layered continuation family — '419, '259, '582, '444, '445 share a 2006-02-08 priority and a substantively identical specification; killing the '419 alone leaves four siblings standing, so any IPR-based defense should be portfolio-wide. (4) CAO is PTAB-literate as a petitioner (IPR2014-00796/-00798), so it will not be surprised by an IPR campaign — but it has never had to defend one.

Recommended next steps

• If you are a defendant facing an assertion demand or suit on the '419: there is no FWD and no canceled claim to point to, so do not tell the court otherwise. Your playbook is either (a) a § 315(b)-timely IPR grounded on the P&G Sagel references (U.S. 5,891,453 / 5,894,017 / 7,122,199) in view of the PEO/PVP-thickened-peroxide art cited on the '419's face, or (b) a district-court § 102/§ 103 defense mirroring the N.D. Ill. Cheng outcome — https://storage.courtlistener.com/recap/gov.uscourts.ilnd.455246/gov.uscourts.ilnd.455246.102.0.pdf.
• Confirm the null result before relying on it. Because ODP ingest lags, run a live PTAB E2E search (https://ptacts.uspto.gov/ptacts/) by patent number 10,646,419 and by patent owner CAO Group, Inc. immediately before you file anything. If a petition has appeared, note the statutory one-year trial deadline from institution (35 U.S.C. § 316(a)(11)) and the § 314(b) three-month institution deadline for timeline planning.
• Factor in expiration. With the patent past its 2026-02-08 anticipated expiration, weigh whether the cost of an IPR is justified against a past-damages-only exposure — and whether the owner's live continuation patents ('444, '445, and pending applications 18/348,960 and 18/459,268) make a portfolio-wide invalidity strategy rather than a single-patent IPR the better investment.
• State the absence plainly in any client memo: this patent has never been to the PTAB. That is itself a signal — a five-continuation family asserted against Walmart, Ranir, Ivoclar Vivadent, GuruNanda, and dozens of Amazon sellers has, to date, attracted zero AIA challenges, which usually means either the defendants are judgment-proof small sellers or the validity case has not looked worth $500K+ to a well-heeled infringer.

I'll research this patent's ownership chain, the assignees, litigation, and any NPE-related signals.

Let me dig into the specific assignment records and Cao Group's corporate/products posture.

Assignment & Ownership Analysis — US 10,646,419 B2

Patent: US 10,646,419 B2 — "Peroxide gel compositions"
App. No.: 15/627,906 · Filed: 2017-06-20 · Issued: 2020-05-12 · Priority: 2006-02-08 · Anticipated expiry: 2026-02-08 · Status: Expired – Lifetime
Verification links: USPTO Assignment Center · legacy Assignment Search (search by patent number 10646419) · Google Patents legal events

Data caveat up front. The USPTO Assignment Center's per-record detail (correspondent/attorney of record) for the three reels in this chain was not retrievable from the sources available to me; the reel/frame numbers, conveyance type, assignor, assignee, execution dates and recording dates below come from the Google Patents legal-events mirror of the USPTO assignment record, which I treat as the authoritative text supplied. I explicitly flag below where a correspondent value is unknown rather than inferred. I found no shell-entity, no NPE-listed assignee, and no security/license/release records on this patent.

Inventors

Discrepancy to flag (do not auto-correct): The granted patent front page names only Steven D. Jensen as inventor, yet the recorded assignments on this patent list both Jensen and "Cao, Densen, Dr." as assignors into CAO Group, Inc. Cao is a co-inventor on the sibling '259 patent (US 10,603,259) per CAO's complaints, and on the parent filings (e.g., US 11/307,463 / US 12/329,582 family, where "Steven D. Jensen; Densen Cao" appear together on CAO's foreign counterparts). The most likely explanation is that the confirmatory assignments were recorded against the whole family, but this should be verified against the actual assignment documents before relying on it.

Unusual-pattern check — not present: There is no evidence of inventors departing the original assignee post-filing. Both Jensen and Cao remained with CAO (Cao is still founder/CEO of CAO Group and AMD Lasers as of 2026; Jensen was still described as a current CAO chemist in 2024 pleadings). No departure-then-fire-sale precursor.

Original assignee

CAO Group, Inc. (sometimes shown as "Cao Group LLC" in Google Patents' "Original Assignee" field) — a Utah corporation at 4628 West Skyhawk Drive, West Jordan, Utah 84084.

• Business: An operating company, not a holding vehicle. Founded in 2000 by Dr. Densen Cao; develops and manufactures dental, medical, forensic and LED-lighting products (LED curing lights, diode dental lasers, forensic light sources, whitening products). 60,000 sq-ft FDA-registered / ISO 13485-9001 facility in West Jordan; joint-venture manufacturing via CAO (China) Medical Equipment Co., Ltd.
• Product embodying the claims: Yes. CAO ships Sheer White! / SheerWhite® whitening strips ("SheerFilm" delivery system) — thin, flexible, moldable films with a gelatinous, visco-elastic carbamide/hydrogen-peroxide gel — sold through major dental distributors (Benco, Henry Schein/Zahn, etc.). This is the product CAO accuses others of copying and the product alleged to embody the '419 claims.
• Current status: Operating as of the sources reviewed. No bankruptcy, dissolution or acquisition of CAO Group was found. (Its LED-patent history shows a divestiture/divestment pattern in the opposite direction — CAO assigned LED patents out to Epistar/others — but that does not touch this dental family.)
• Entity-form note: Google Patents shows "Original Assignee: Cao Group LLC" vs "Current Assignee: Cao Group Inc." The recorded assignments and all litigation name CAO Group, Inc. The LLC/Inc. difference appears to be a data artifact rather than a real corporate conversion; treat as unverified.

Assignment timeline

Total recorded assignments on US 10,646,419: 3 (all into the same operating-company assignee; none is an arm's-length sale). All three are confirmatory / nunc-pro-tunc "assignment of assignors' interest" recordings — note that every execution date is in 2015 while every recording date is in 2021–2022, i.e., the documents were perfected years after the fact, ahead of CAO's enforcement campaign.

• 2015-05-20 (executed) / recorded 2021-10-30 — Reel 057970/0876

  • Conveyance: Assignment of Assignors' Interest (see document for details)
  • Assignor: Jensen, Steven D., Mr.
  • Assignee: CAO Group, Inc., 4628 West Skyhawk Drive, West Jordan, UT 84084
  • Correspondent: Unknown — not retrievable for this reel from available sources. (For context only, CAO's historical recording correspondent across older CAO patents is Daniel P. McCarthy, Parsons Behle & Latimer, 201 South Main Street, Suite 1800, Salt Lake City, UT 84111, e.g. reels 012126/0261 and 017962/0419; a later CAO-related recording used Magleby, Cataxinos & Greenwood P.C., 170 S. Main St., Suite 1100, Salt Lake City, UT 84101 (reel 040124/0185). I cannot confirm which firm filed these 2021–2022 reels.)
  • Context: Internal chain-of-title perfecting — inventor assigns to his employer's operating company; confirmatory, not a sale.

• 2015-05-29 (executed) / recorded 2021-10-30 — Reel 057970/0880

  • Conveyance: Assignment of Assignors' Interest (see document for details)
  • Assignor: Cao, Densen, Dr.
  • Assignee: CAO Group, Inc.
  • Correspondent: Unknown (as above).
  • Context: Internal chain-of-title perfecting — founder/co-inventor's confirming assignment to CAO Group, Inc.

• 2015-05-29 (executed) / recorded 2022-01-06 — Reel 058585/0251

  • Conveyance: Assignment of Assignors' Interest (see document for details)
  • Assignor: Cao, Densen, Dr.
  • Assignee: CAO Group, Inc.
  • Correspondent: Unknown (as above).
  • Context: Internal re-recording / duplicate confirmatory assignment (same assignor, same effective date as the prior Cao entry) — the classic "belt-and-suspenders" re-record pattern used to shore up standing before asserting.

Related (non-assignment) legal event:

• 2022-07-05 — Certificate of Correction issued (not a conveyance; listed for completeness).
• 2024-02-26 — 4th-year maintenance fee paid (small entity), later surcharge — routine, no ownership significance.

No security agreements, licenses, mergers, name-changes, or releases are recorded on this patent.

Timeline diagram

timeline
    title Ownership of US 10646419
    2006 : Priority date
    2017 : Application filed by Cao Group
    2020 : Patent issued to Cao Group Inc
    2021 : Confirmatory assignment from Jensen
         : Confirmatory assignment from Cao
    2022 : Second Cao confirmatory assignment
         : Certificate of correction issued
    2024 : CAO sues Walmart  rivals  online sellers
    2025 : CAO sues GuruNanda in C D Cal

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT.
Every recorded assignment lands at CAO Group, Inc., 4628 West Skyhawk Drive, West Jordan, UT 84084 — the same operating address used in CAO's FDA/ISO product literature and in its litigation complaints. There is no "IP / Licensing / Holdings / Ventures" successor, no registered-agent-only address, no single-member Delaware/Texas LLC anywhere in the chain (reels 057970/0876; 057970/0880; 058585/0251).

2. Known asserter in the chain — NOT PRESENT.
No assignee or predecessor matches the enumerated NPE universe (Acacia, Marathon, IV, IPNav, Wi-LAN, Conversant/Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation, Spangenberg entities) or appears on Stanford's NPE database as an owner. Stanford's NPE Litigation Database indexes the asserted patents (e.g. US 11,826,444) but lists CAO Group Inc as the plaintiff operating company, not as an NPE owner.

3. Repeat correspondent across the chain — UNCLEAR (not verifiable).
I could not retrieve the correspondent of record for the three reels in this chain, so I cannot assert recurrence. Note, however, that the recurrence that is documented on the wider CAO portfolio is the opposite of an NPE tell: CAO has used Parsons Behle & Latimer (Daniel P. McCarthy) for its own inventor-to-company assignments going back to 2001–2006 (reels 012126/0261, 017962/0419) — a single operating company re-recording its own title, which is normal in-house practice, not a shell-LLC carousel. Cited only as context; not a finding as to the '419 reels.

4. Cascading transfers — NOT PRESENT.
Three recordings over ~2.5 months (2021-10-30 → 2022-01-06) all go to the same assignee; there is no chained series of distinct LLCs sharing a correspondent or principal.

5. Pre-litigation transfer — NOT PRESENT (timing), but note a perfecting pattern.
The recordings (2021-10-30, 2022-01-06) precede the first '419 infringement suits (Feb 2024) by more than 24 months, so the strict "<6 months before suit" test fails. However, the fact that 2015-executed confirmatory assignments were only recorded in 2021–2022 is a recognised standing/chain-of-title cleanup pattern seen when a patent owner is preparing to assert. It is a genuine observation, not an NPE signal per se, because the clean assignee is the operating company itself.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11 for CAO Group, and no court-supervised sale of this patent was found.

7. Privateering — NOT PRESENT. CAO did not transfer the patent to a third party who then sued on its behalf; CAO sues in its own name as owner.

8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT, Unified Patents or OIN. Inverse signal absent — the patent remains a live assertion asset held by the operating company.

Additional enforcement-tactic observation (not an ownership signal but worth recording). CAO's 2024–2025 campaign uses the "Schedule A" mass-defendant model — e.g. CAO Group, Inc. v. The Individuals … Identified on Schedule A, 1:24-cv-01211 (N.D. Ill., filed 2024-02-12) — with ex parte TROs, asset freezes, and default judgments of ~$1,518,750 per defaulting defendant (trebled under §284), and parallel actions against Walmart (D. Utah 2:24-cv-00175, dismissed with prejudice), GD Whitening (1:24-cv-05129), Karaka/Boka (1:24-cv-04903), GuruNanda (C.D. Cal. 8:25-cv-02074, filed 2025-09-12), a Delaware action (1:25-cv-01430), and a declaratory-judgment counterattack by Ranir LLC / Perrigo (D. Utah 2:24-cv-00498). Schedule-A/asset-freeze litigation is a tactic more commonly associated with NPE-style plaintiffs, but here it is wielded by a product company against private-label retailers and offshore sellers.

Verdict

Operating-company assertion.

The chain never leaves CAO Group, Inc. — a Utah dental-products manufacturer that ships the Sheer White!/SheerWhite® whitening strip embodying the '419 claims — and every recorded transfer (reels 057970/0876, 057970/0880, 058585/0251) is an internal confirmatory assignment into that same operating company, not a transfer to a licensing-only shell. CAO is asserting the patent in its own name against private-label and third-party sellers (Walmart Equate, GuruNanda, GD Whitening, Karaka/Boka) rather than through an NPE vehicle, and is itself the target of a declaratory-judgment suit by Ranir/Perrigo — the hallmark of a product company defending market share. No shell-entity, NPE-list, cascading-transfer, bankruptcy, privateering or defensive-aggregator signal is present; the only findings worth noting are the multi-year-late recording of 2015-executed confirmatory assignments (2021–2022) and CAO's aggressive Schedule-A mass-suit tactics, neither of which changes the ownership classification.

Verification: search patent number 10646419 at the USPTO Assignment Center or assignment.uspto.gov; recordation detail mirrors at Google Patents (legal events) and Unified Patents (patent page).

I'll research each cited reference, prioritizing the ones most likely to bear on § 102 anticipation (backing strip + peroxide + thickener chemistry). Let me search authoritative sources.

Let me research the remaining key references, especially the PVP/peroxide-complex art and the polymeric-hydrogel references.

Prior-Art Analysis — US 10,646,419 B2 ("Peroxide Gel Compositions")

Note on search scope, method, and a date contradiction

Method. I ran targeted web searches against Google Patents, FreePatentsOnline, EPO/Espacenet, PubChem, USPTO PTAB/PTACTS documents, and Unified Patents for the specific number 10,646,419. I did not run a bulk PACER/USPTO-Office-Action database query, so examiner-cited art and the content of the July 5, 2022 certificate of correction are not fully reconstructed. Descriptions of a few references are derived from titles/abstracts plus general knowledge and are flagged where I could not retrieve full text.

⚠ Contradiction to flag: The previously generated section states "Current Date: April 26, 2026." The governing date for this task is September 28, 2026. This matters: the patent text lists an anticipated expiration of Feb. 8, 2026 (20 years from the earliest priority filing, US 11/307,463), and the status is "Expired – Lifetime." As of Sept. 28, 2026 the patent is therefore past its nominal term on either date — but the approximately five-month gap should be reconciled before relying on the prior section's "current date" statements. I also could not verify the examiner name ("Lezah Roberts") cited in the prior summary; it does not appear in the authoritative patent text provided.

Threshold legal point (important)

No reference in the citation list appears to anticipate claims 1, 16, or 28 under 35 U.S.C. § 102. For § 102 anticipation, a single reference must disclose every element as arranged in the claim. The independent claims require the combination of:

• a flexible, planar backing strip, with the composition covering substantially all of one flat side solely;
• a peroxide bleaching agent + water (+ organic solvent in claims 16/28);
• a thickening agent that is poly(2-ethyl-2-oxazoline) and/or PVP;
• a composition that is dried after application and remains gelatinous/visco-elastic (a) after drying, (b) through up to six months' room-temperature storage, (c) after opening, (d) while flexibly placed on teeth;
• conformability, retention on the strip, and adhesion to teeth (claims 16/28 add "deform under its own weight").

The cited art largely establishes individual elements (peroxide/dental-strip devices, or PEOX/PVP chemistry). That supports § 103 combinations, not clean § 102 anticipation — except the closest PVP-based references discussed below, which merit a § 102 look for the PVP-alternative limitations.

Most relevant prior art — ranked

Tier 1 — Closest to the claims

1. US 2004/0241110 A1 — "Jelly-type tooth-bleaching patch" (Sang-Ho Lee)

• Filed May 26, 2004 (family App. 10/854,542); published Dec. 2, 2004.
• Disclosure: A patch comprising a thin polyethylene film, a jelly-type adhesive on the film containing peroxide, and moisture-proof wrapping paper. The coating-forming agent is expressly "at least one … selected from polyvinyl pyrrolidone, polyvinyl alcohol, sodium alginate, hydrogen peroxide 2-pyrrolidinone 1-ethenyl-homopolymer…" (¶19; claim 9). Peroxide list includes hydrogen peroxide and carbamide peroxide (¶14; claim 4).
• § 102 relevance — highest of the set. This is the only cited reference that combines (i) a flexible film/backing, (ii) a gelatinous ("jelly") peroxide composition, and (iii) PVP as a recited polymer. Because claim 1 recites the thickening agent as "at least one of poly(2-ethyl-2-oxazoline) and polyvinylpyrrolidone," reference '110 arguably reads on the PVP alternative of claim 1 (and dependent claims 11, 24). Gap to litigate: '110 does not recite a drying step, a six-month storage-stability requirement, or the "deform under its own weight" limitation of claims 16/28 — so a full § 102 hit on independent claims 1/16/28 is doubtful, but '110 is the strongest single-reference candidate and the best § 103 primary reference.
• Source: https://patents.google.com/patent/US20040241110 (PDF: patentimages .../US20040241110A1.pdf)

2. Ultradent "substantially solid" tray/strip family — US 6,860,736 B2; US 7,056,118 B2; US 7,059,857 B2; US 6,730,316 B2

• US 6,860,736 B2 — filed May 23, 2003; issued Mar. 1, 2005.
• US 7,056,118 B2 — filed Aug. 22, 2003 (priority May 27, 2003); issued Jun. 6, 2006.
• US 7,059,857 B2 — priority May 27, 2003; issued Jun. 13, 2006.
• US 6,730,316 B2 — priority Jan. 27, 2001; issued May 4, 2004.
• Disclosure: Substantially solid medicament/bleaching/desensitizing compositions in a tray-like or strip configuration that become more adhesive when moistened with saliva or water, used with a moisture-resistant barrier layer. This mirrors the applicant's own "dried gel that is re-wetted to become adhesive" concept.
• § 102 relevance — high on the physical-form element, low on chemistry. These references teach the dried/substantially-solid → moistened-adhesive behavior and the backing/barrier, i.e., essentially every structural element of claim 1. Their gap is the thickener identity: they describe carbomer/carboxypolymethylene-type chemistry, not PEOX. Not a full § 102 anticipation of claims 1/16/28; strongest as § 103 art on the structural limitations.
• Sources: https://patents.google.com/patent/US7056118 (PDF); https://pubchem.ncbi.nlm.nih.gov/patent/US-[7056118](/patent/7056118)-B2

Tier 2 — Tooth-whitening strip/tray structural art (P&G, Colgate, LG, Dentsply, 3M)

3. The Procter & Gamble "strip of material" family

• US 5,891,453 A — filed Jun. 6, 1997; issued Apr. 6, 1999 — "Delivery system for a tooth whitener using a strip of material having low flexural stiffness."
• US 5,894,017 A — filed Jun. 6, 1997; issued Apr. 13, 1999 — strip of material with flexural stiffness < ~50 g/cm; oral care substance.
• US 6,045,811 A — filed Jun. 6, 1997; issued Apr. 4, 2000 — permanently deformable strip.
• US 6,136,297 A — filed Jun. 6, 1997; issued Oct. 24, 2000.
• US 6,884,426 B2 and US 7,122,199 B2 — priority Jun. 6, 1997; issued Apr. 26, 2005 and Oct. 17, 2006 — "Methods for whitening teeth."
• US 2002/0006387 A1; US 2007/0003495 A1; US 2007/0253990 A1; US 2007/0269471 A1 — priority Jun. 6, 1997; published Jan. 17, 2002; Jan. 4, 2007; Nov. 1, 2007; Nov. 22, 2007.
• Disclosure (representative, '453/'017): A flexible, conformable flat strip coated with a tooth-whitening gel/matrix that both delivers active and provides adhesive attachment to teeth. Silica and carboxypolymethylene ("Carbopol") are the preferred gelling agents; PVP is among many optional gelling/binder polymers; whitening actives include hydrogen peroxide, carbamide peroxide (0.01–40 wt%).
• § 102 relevance: Discloses the backing-strip + peroxide gel + adhesion/conformability elements. Gap: thickener is Carbopol/carboxypolymethylene (expressly distinguished by the patent), typically not PEOX; '453/'017 teach a wet gel, not a dried gelatinous composition. No § 102 anticipation; core § 103 art.
• Sources: https://patents.google.com/patent/US5891453 ; https://patentimages.storage.googleapis.com/a8/85/a4/ea6cee608fde9d/US5894017.pdf

4. US 6,512,483 B2 — Colgate-Palmolive — priority Mar. 12, 2001; issued Feb. 4, 2003 — "Strip for whitening tooth surfaces." Flexible whitening strip. Structural analog to the '419 strip; different chemistry. § 103 art.

5. US 6,582,708 B1 — P&G — priority Jun. 28, 2000; issued Jun. 24, 2003 — "Tooth whitening substance." A substantially solid (flowable-to-solid) whitening substance using PEG/carbomer-type gelling systems; potentially relevant to the "dried/visco-elastic" element. § 103 art.

6. US 6,685,923 B2 — Dentsply — priority Jan. 25, 2001; issued Feb. 3, 2004 — "Tooth whitening material and method of whitening teeth." § 103 art.

7. LG Household & Healthcare patch family

• US 6,780,401 B2 — priority Mar. 17, 2000; issued Aug. 24, 2004 — "Patches for teeth whitening."
• US 7,862,802 B2 — priority Mar. 17, 2000; issued Jan. 4, 2011 — "Patches for teeth whitening."
• US 2004/0136927 A1 — priority Mar. 17, 2000; published Jul. 15, 2004 — "Apparatus and method for whitening teeth."
• § 102 relevance: Patches/hydrogel strips with peroxide for whitening — discloses the backing + peroxide + adhesive elements; different polymer chemistry. § 103 art.

8. 3M references

• US 6,315,566 B1 — filed May 18, 1999; issued Nov. 13, 2001 — "Dental materials."
• US 6,322,360 B1 — filed Oct. 22, 1999; issued Nov. 27, 2001 — "Medication retention assembly for oral delivery tray."
• US 6,765,038 B2 — filed Jul. 27, 2001; issued Jul. 20, 2004 — "Glass ionomer cement."
• § 102 relevance: Low. '566/'360 are dental-material/tray delivery art (structural context only); the glass-ionomer reference is unrelated to peroxide gels.

Tier 3 — Peroxide/bleach chemistry (not device-form)

9. US 2002/0155070 A1 (Tianming Chen) — priority Jan. 27, 2001; published Oct. 24, 2002 — "Enamel-safe tooth bleach."
10. US 6,500,408 B2 (JC Technologies / Chen) — priority Jan. 27, 2001; issued Dec. 31, 2002 — "Enamel-safe tooth bleach and method for use."
11. US 6,730,316 B2 (Ultradent / Chen) — issued May 4, 2004 — "Dental bleach."

• § 102 relevance: Disclose high-peroxide bleaching compositions (relevant to the peroxide-concentration and enamel-safety limitations) but not the backing-strip + dried gelatinous PEOX structure. § 103 art.

12. US 2003/0073150 A1 (Woerner) — priority May 9, 2001; published Apr. 17, 2003 — "Stabilization of H₂O₂ under alkaline conditions …" — hydrogen-peroxide stabilization chemistry; not a dental device. Low relevance.

Tier 4 — Polymer/backing chemistry and general hydrogel art

13. US 4,144,211 A (Dow Chemical; Bangs & Chamberlin) — prior-art date Sep. 6, 1977; issued Mar. 13, 1979 — "Novel complexes of polyoxazolines or polyoxazines and halogens, interhalogens or pseudo-halogens…"

• Disclosure: Complexes of polyoxazolines with halogen/pseudo-halogen oxidizing species.
• § 102 relevance: The single most important chemistry reference to the PEOX element — it establishes that polyoxazolines (the class encompassing poly(2-ethyl-2-oxazoline)) form stable complexes with strong oxidizers. But it discloses neither a dental device, a peroxide (its oxidizing agents are halogens), nor a dried gelatinous form → no § 102 anticipation of any claim; it is § 103 art bearing on the "superior polymer in an oxidizing environment" premise.
• Source: https://patents.google.com/patent/US4144211 ; https://uspto.report/patent/grant/[4144211](/patent/4144211)

14. US 5,470,930 A (Nippon Shokubai) — filed Feb. 16, 1994 (priority Feb. 18, 1993); issued Nov. 28, 1995 — "Process for producing polymer having hydroxyl group at both terminals." Uses hydrogen peroxide as a polymerization initiator. Not a dental composition → no § 102 relevance.

15. US 6,080,889 A (Albemarle) — filed Apr. 1, 1998; issued Jun. 27, 2000 — "Production of tertiary amine oxides." Peroxide-oxidation process chemistry. Low/§ 103 only.

16. US 6,113,629 A (Micrus) — filed May 1, 1998; issued Sep. 5, 2000 — "Hydrogel for the therapeutic treatment of aneurysms." Hydrogel art; non-dental. Low.

17. US 2004/0105834 A1 (Corium International) — priority May 1, 2001; published Jun. 3, 2004 — "Hydrogel compositions with an erodible backing member." Hydrogel-on-backing concept, but the backing erodes (dissolves) — the opposite of the '419 insoluble strip. § 103 art on the backing/hydrogel concept; no § 102.

Tier 5 — Additional tray/strip and design references (low § 102 weight)

• US 2005/0186150 A1 (Allred) — priority Feb. 19, 2004; published Aug. 25, 2005 — "Dental bleaching devices having a protective adhesive region."
• US 2005/0255054 A1 (Philp) — priority Apr. 30, 2004; published Nov. 17, 2005 — dissolvable tray or strip.
• US 2005/0276760 A1 (Lornamead Brands) — priority Jun. 9, 2004; published Dec. 15, 2005 — tooth-whitening products.
• US 2009/0130624 A1 (Sun) — priority Nov. 20, 2007; published May 21, 2009 — flexible dental guards.
• § 102 relevance: Structural/delivery variants only; none discloses PEOX or the dried visco-elastic peroxide composition. § 103 background art.

Non-patent literature (cited)

Bottom line

• No single cited reference discloses all elements of claims 1, 16, or 28, principally because none discloses poly(2-ethyl-2-oxazoline) as the thickener in the recited dried, gelatinous, visco-elastic peroxide composition that survives six months' storage. The claims are therefore better characterized as facing a § 103 attack than a § 102 attack.
• Closest § 102 candidate: US 2004/0241110 A1 (Lee, "Jelly-type tooth-bleaching patch") — because it alone combines a film backing + peroxide + PVP in a gelatinous patch, and claim 1 recites PVP as an alternative thickening agent. The absence of an express drying step and of the six-month/deform-under-weight limitations is the decisive gap for full anticipation of independent claims 1/16/28.
• Best § 103 primary reference: Lee '110 or the Ultradent substantially-solid family (US 6,860,736 / 7,056,118 / 7,059,857), combined with US 4,144,211 (Dow, polyoxazoline–oxidizer complexes) and the ISP PVP–H₂O₂ bulletin (to supply the PEOX/PVP-peroxide compatibility), and a P&G strip reference (to supply the flexible-strip structure).
• Chemistry-specific art: US 4,144,211 and the Aquazol MSDS are the references that most directly touch the asserted point of novelty (the thickener), while the ISP bulletin touches the PVP alternative.

Caveats

1. I could not retrieve full text for a few references (e.g., Colgate '483, Dentsply '923, LG '401/'802, Corium '834); their descriptions rest on titles/abstracts and general knowledge and should be verified against the full documents before being relied upon.
2. The § 102 vs. § 103 characterization assumes the Feb. 8, 2006 priority date governs all claims, consistent with the provided patent text. If any claim enjoys a later effective filing date, some cited NPL (Gowda/Kadajji 2011; the 2017 gel references) could still qualify as prior art, but that analysis is fact-specific.
3. The date contradiction between this task (Sept. 28, 2026) and the prior section (Apr. 26, 2026) — and its effect on the expired-term analysis — should be resolved before finalizing any opinion.

I'll ground the key prior-art references before building the § 103 analysis.

Obviousness Analysis Under 35 U.S.C. § 103 — US 10,646,419 B2

Builds on the prior "Patent summary" section (bibliographic data, claim overview, technical core). The claim-language characterization and family/priority data there are treated as authoritative and are not repeated.

0. Analytical posture and a threshold caveat

Under Graham v. John Deere Co., 383 U.S. 1 (1966), I address: (1) the scope/content of the prior art; (2) the differences between the prior art and the claims; (3) the level of ordinary skill; and (4) secondary considerations. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), supplies the governing rationales for combining.

Threshold — which references actually qualify. The patent text lists an earliest priority of Feb. 8, 2006. If the issued claims are entitled to that date, then several references the examiner cited are not § 102/§ 103 prior art because they post-date it:

The fact that the examiner cited 2011 and 2017–2019 documents is itself a signal: either the examiner treated the effective filing date as the June 20, 2017 filing (making those references available), or cited them only as background/evidence of the state of the art. For any § 103 challenge, the effective filing date is the pivotal issue, because the entire 2006-vintage strip-and-peroxide body of art is indisputably available, while the PEOX-specific and gel-characterization references are only available under a post-2006 anchor. I flag this as unresolved (I could not verify from the retrieved text whether the claims are fully supported by the Feb. 8, 2006 application). Both scenarios are analyzed below; the 2006-anchored combination is the stronger and cleaner one.

1. Level of ordinary skill in the art (ECSS)

A POSITA here would be a formulator in dental/oral-care or topical-bleaching chemistry with: (a) a bachelor's or graduate degree in chemistry, pharmaceutics, or polymer science and ~2–5 years' experience formulating peroxide gels; (b) familiarity with the standard thickener palette (carbomer/CARBOPOL, PVP, silica, PEG, poloxamer, cellulosics); (c) knowledge of the strip/tray delivery formats popularized by P&G and Ultradent in the late 1990s–2000s; and (d) routine ability to screen water-soluble polymers for compatibility with aqueous H₂O₂. This is a mature, well-populated, and highly predictable art — a fact that strengthens the § 103 case.

2. Scope and content of the prior art, grouped by claim element

I group the patent's own cited art by the claim limitation it maps to.

Group A — Flexible planar strip + peroxide gel on one side, conformable and adhesive to teeth

• US 5,894,017 / US 5,891,453 / US 6,045,811 / US 6,136,297 / US 6,582,708 (all The Procter & Gamble Co.) — "delivery system for an oral care substance using a strip of material having low flexural stiffness." US 5,894,017 expressly discloses a strip "readily conformable without permanent deformation," coated with an oral care substance in the form of a gel that "provide[s] adhesive attachment between the strip and the surface" and holds the strip in place. Its background note even contemplates a "gel containing urea/hydrogen peroxide complex." US 6,045,811 claims a "permanently deformable strip." These teach the exact device architecture of claim 1 — flat strip, gel on one side, conformance, adhesion, retention on teeth.
  • https://patents.google.com/patent/US5894017
• US 6,514,483 B2 (Colgate-Palmolive) — "strip for whitening tooth surfaces."
• US 7,862,802 / US 6,780,401 (LG Household & Health Care) and US 2004/0136927 A1 (Kim) — tooth-whitening patches (backing + hydrogel whitening layer).
• US 6,685,923 B2 (Dentsply) — tooth-whitening material; US 6,312,360 B1 / US 6,315,566 B1 (3M) — dental materials and a medication-retention oral tray.

Group B — Dried / "solid" gelatinous layer on a backing (the "dried after application" limitation)

• US 6,860,736 B2 (Ultradent) — oral treatment device with a thin, flexible barrier layer and an "endoskeleton" treatment/adhesive composition.
• US 7,056,118 B2 / US 7,059,857 B2 (Ultradent) — compositions "having a tray-like configuration" and "substantially solid desensitizing compositions."
• US 6,997,708 B2 / US 7,011,523 B2 (Ultradent) (listed under "Similar Documents") — devices with a "solid adhesive layer" and a treatment/bleaching gel adjacent.
• US 2004/0241110 A1 (Sang-Ho Lee) — "Jelly-type tooth-bleaching patch."
• US 2005/0255054 A1 (Philp) — dissolvable tray/strip; US 2005/0186150 A1 / US 7,192,280 B2 (Allred) — bleaching devices with a protective adhesive region.
• US 6,730,316 B2 (Ultradent), US 6,500,408 B2 / US 2002/0155070 A1 (Chen/JC Technologies) — dental bleach compositions.

Together these teach applying a viscous/solid bleaching composition onto a backing and allowing it to set/dry — the "dried after being applied" and "visco-elastic gelatinous layer" concepts.

Group C — Peroxide-compatible thickeners, including the claimed species

• US 4,144,211 (The Dow Chemical Co., 1979) — "Novel complexes of polyoxazolines or polyoxazines and halogens, interhalogens or pseudo-halogens." This is a direct teaching that polyoxazolines are chemically robust toward powerful oxidizers (halogens/pseudo-halogens) and form stable complexes therewith. https://patents.google.com/patent/US4144211
• ISP Technical Bulletin, Hydrogen Peroxide–Polyvinylpyrrolidone Polymer Complexes (2004) — expressly teaches that PVP is compatible with hydrogen peroxide and forms defined PVP–H₂O₂ complexes (the "Peroxydone" family). This squarely supports the claim's PVP alternative (claims 11, 24) and the PVP/PEOX Markush in claims 1, 16, 28.
• US 6,080,889 A (Albemarle) — tertiary amine-oxide production (related N-oxide/amine chemistry).
• Polymer Chemistry Innovations, "Aquazol 5/50/200/500," MSDS (2002) — identifies poly(2-ethyl-2-oxazoline) by trade name and grades (50k / 200k / 500k MW), and its water-soluble, gel-forming character. This is the reference that puts the specific claimed polymer and the specific molecular weights recited in the specification's examples in the public domain before 2006.
• Aldrich Catalog 2005–2006 — commercial availability of PEOX.
• Imming et al., J. Med. Chem. 43:4328–4331 (2000) — "Hydrolytic Stability versus Ring Size in Lactams." Both PVP (a lactam-derived polymer) and PEOX (a poly(N-acyl ethylenimine) whose backbone is an amide) share the amide/lactam motif; this paper informs a POSITA that hydrolytic stability of such rings is predictable from ring size — i.e., that the stability behavior of these polymer classes was knowable, undercutting any "unexpected stability" argument.
• Gowda/Kadajji, Polymers 3:1972–2009 (2011) — survey of water-soluble polymers for pharmaceutical use (available only under a post-2006 anchor).

Group D — Elevated peroxide concentration

• AU 778,646 B2 (Discus Dental) — "Increased peroxide content tooth bleaching gel" (family publication EP 1,210,062 A2). This reference expressly addresses the same problem the patent asserts as its advance — raising the H₂O₂ concentration of a bleaching gel — and notes that the art conventionally gelled H₂O₂ with carboxypolymethylene (Carbopol), poloxamer (Pluronic), and cellulosic gums. It directly supports claims 14, 15, 27, 35 (peroxide ranges) and shows the motivation to increase peroxide load was pre-existing. https://patents.google.com/patent/EP1210062A2/en

Group E — Gel visco-elasticity / "deform under its own weight"

• Velesco Pharma, "Science Behind Gels" (2017) and the food-gel references (Wikipedia "Nokdu-Muk" (2019); Kim, "How to Make Korean Jello" (2017)) — describe the physical behavior of gels (visco-elastic, self-leveling/deforming, non-coalescing). Notably, these were submitted by the applicant/examiner during prosecution, which suggests the Examiner was probing the metes-and-bounds of "gelatinous" — relevant to both § 112 and to the obviousness of the "deform under its own weight" functional limitation (claims 16, 28). Caveat: only available under a post-2006 anchor.

3. Differences between the prior art and the claims

Stripping the claims to their substance (per the claim overview already generated), the asserted advance resolves to two differences over the strip-art of Groups A/B:

1. Selection of the thickener: PEOX (or PVP) instead of carbomer/Carbopol, silica, PEG, etc.
2. Functional characterization: the composition must remain a gelatinous, visco-elastic, tooth-adherent layer through drying, up-to-six-months packaged storage, removal, and placement — and (claims 16/28) "deform under its own weight."

Everything else — flexible planar strip with two flat sides; composition covering substantially all of one side; drying after application; conformance to adjacent teeth; adhesion/retention — is squarely in Groups A/B. The ratio, molecular-weight, viscosity, and concentration sub-limitations (claims 5–10, 13–15, 17, 19–23, 26–27, 31–35) are results of routine formulation optimization, not independent inventions.

4. Primary obviousness combinations and motivations

Combination I (core, 2006-anchored) — P&G strip art + a peroxide-stable thickener (PEOX/PVP)

Primary refs: US 5,894,017 (and its P&G siblings) in view of Aquazol MSDS (2002), US 4,144,211 (Dow), and the ISP PVP–H₂O₂ Bulletin (2004); optionally US 6,860,736 / US 7,059,857 (Ultradent) for the dried/solid-layer feature.

Motivation to combine (KSR):

• Known problem in the field. The specification itself concedes the art knew "very few thickeners… can withstand a peroxide environment" and that "most polymers will degrade quickly" — a recognized, unmet need. AU 778,646 and the LC Technologies/EU case law (see the EPO Board decision in the search results re: carbamide+H₂O₂ bleaching gels) confirm the field was actively seeking higher-peroxide, more-stable gels.
• Finite number of predictable solutions. A POSITA seeking a H₂O₂-stable water-soluble thickener would canvass the known palette of water-soluble polymers — PVP, polyoxazolines, PEG, poloxamer, cellulosics — a small, enumerated set. The ISP Bulletin already told the POSITA that PVP tolerates H₂O₂, and the Dow '211 patent already taught that polyoxazolines form stable complexes with strong oxidizers.
• Substitution of one known element for another to obtain its known property. Replacing carbomer with a polymer known to be oxidizer-compatible, to achieve oxidative compatibility, is the paradigm KSR "predictable variation." No change in the principle of operation of the strip; the strip still carries an adhesive gel to the teeth.
• Design incentive / commercial pressure. The strip format (P&G) and the "solid/gelatinous layer" format (Ultradent) were established commercial platforms; improving the gel's stability and peroxide payload was an obvious objective.

Result: Claims 1, 12, 16, 28 (and the PVP species claims 11, 24) would have been obvious. The four-stage "gelatinous/visco-elastic" limitation is either (i) an inherent property of any properly formulated PEOX/PVP gel on a strip, or (ii) at most a result-effective property that a POSITA would expect from selecting a known gel former — not a patentable discovery.

Combination II — Ultradent solid-layer art + PEOX/PVP

Primary refs: US 6,860,736; US 7,056,118; US 7,059,857; US 6,997,708 / US 7,011,523 in view of Aquazol MSDS + Dow '211 + ISP Bulletin.
Why motivated: Ultradent already teaches a dried/solid, tray-like, flexible barrier-borne bleaching layer; substituting a known peroxide-compatible thickener to make that layer peroxide-stable and self-adherent is an obvious improvement of the same device. This combination is especially useful against the "dried after being applied" and "substantially all of one side covered solely by the dental composition" limitations, which the strip art meets through its "uniform continuous coating" teaching.

Combination III — Adding elevated-peroxide art

Primary ref: AU 778,646 B2 added to Combination I or II.
Why motivated: AU 778,646 is directed to the very same goal (increased peroxide content in a bleaching gel). Its addition renders claims 14, 15, 27, 35 (peroxide at ~11–27%, up to ~50%) facially obvious; the claimed ranges are routine optimization of a disclosed result-effective variable (In re Aller, 220 F.2d 454 (CCPA 1955)) and overlap the art's own ~10–25% carbamide / up-to-20% H₂O₂ teachings.

Combination IV — Gel-property art (post-2006 anchor only)

Primary refs: Velesco "Science Behind Gels" (2017); Kim "Korean Jello" (2017); Wikipedia "Nokdu-Muk" (2019), added to Combinations I/II.
Why motivated / effect: These describe visco-elastic gels that hold shape yet deform under their own weight — the exact functional limitation of claims 16 and 28. If the effective filing date is 2017, this art directly renders the "deform under its own weight" limitation obvious (or at least shows it is a known, expected property of a gel). If the anchor is 2006, this art drops out and the patentee's best non-obviousness argument lives here — but note the same property is arguably inherent in the P&G "gel" teaching and in the applicant's own definitional submissions.

5. Element-by-element chart — claim 1 (representative)

Claims 16 and 28 add only: (i) a recited second organic solvent — fully supported by P&G/Ultradent aqueous-alcoholic gel vehicles and routine solvent selection from the enumerated list (ethanol, PEG, PPG, glycerin, propylene glycol); and (ii) "deform under its own weight," addressed under Combination IV (and inherent-gel arguments). Claim 28 merely recites the device "packaged in a package," met by the release-liner/pouch packaging of the P&G and Ultradent systems (e.g., the release liner in US 2007/0248634 / EP 1,779,846 lineage).

Dependent claims (2–15, 17–27, 29–35) recite the backing being a polymeric wax mixture/PARAFILM-type film, solvent identity, wt% ratios, "about 33–50% thickener," "~11–27%" or "up to ~50%" peroxide, and 1,000–200,000 cPs viscosity — all disclosed as exemplary formulations in the specification itself and otherwise arrived at by routine optimization.

6. Anticipated patentee rebuttals and how they fare

1. "Teaching away" — the art taught to use adducts (carbamide peroxide) because H₂O₂ is too unstable. Weak. The P&G strip art (US 5,894,017/US 6,582,708) and the DAY WHITE/LC Technologies disclosure in AU 778,646 already disclose hydrogen peroxide gels, and the ISP Bulletin (2004) positively teaches H₂O₂–PVP compatibility. Teaching away requires the art to direct a POSITA away from the claimed solution; here the art points toward oxidizer-tolerant polymers. At most, one might argue US 4,144,211 (PEOX–halogen complexes) hints that PEOX reacts with oxidizers rather than resisting them — a double-edged reference I flag explicitly; it is unlikely to rise to a teaching-away because it shows a stable complex, i.e., compatibility, not degradation.

2. "Unexpected results" — six-month stability at 30% H₂O₂. Contestable. The specification asserts this but (per the retrieved text) provides no comparative data against the closest prior art (e.g., a carbomer or PVP gel side-by-side). The Imming lactam-stability paper and the ISP PVP–H₂O₂ work make the result more predictable than the patent implies. A patentee would need commensurate, comparative, reproducible evidence to rebut.

3. Secondary considerations (commercial success of CAO's whitening strips; long-felt need; alleged copying). Requires nexus. Any commercial-success argument must tie the success to the claimed thickener selection, not to the well-established strip format or the brand. Long-felt need is undercut by the fact that H₂O₂ strips were already commercial.

4. Priority defense. The strongest patentee position is to pin the effective filing date to Feb. 8, 2006, which knocks out Velesco (2017), the food-gel references (2017/2019), and Gowda/Kadajji (2011). But even at the 2006 anchor, Combination I survives, because Aquazol (2002), Dow '211 (1979), the ISP Bulletin (2004), the Aldrich catalog (2004), Imming (2000), and the entire strip/solid-layer corpus are all pre-2006. So the priority fight affects which art is available but does not rescue the claims from the core PEOX/PVP-plus-strip combination.

7. Bottom line

• Independents 1, 16, 28 and their PEOX/PVP-species and ratio/concentration dependents are, on the cited art alone, strongly obvious under § 103 over P&G strip art (US 5,894,017 et al.) + Aquazol MSDS / US 4,144,211 / ISP PVP–H₂O₂ Bulletin, with Ultradent solid-layer art supplying the "dried/solid gelatinous layer" element and AU 778,646 B2 supplying the elevated-peroxide ranges. Nearly every element is expressly disclosed; the only genuinely contested limitation is the functional "gelatinous/visco-elastic through six months' storage and 'deform under its own weight' language — a result-effective property that is at best inherent and at worst obvious over the gel-science art (under a post-2006 anchor).
• The single greatest uncertainty is the effective filing date. I could not confirm from the retrieved sources whether the issued claims enjoy full Feb. 8, 2006 support. This matters because it determines whether Group-E gel art is prior art. Even so, the 2006-anchored combination is sufficient to render the claims prima facie obvious.
• Caveat on the Dow '211 reference: it is genuinely two-sided (polyoxazoline–halogen complexes could be read as evidence of reactivity or compatibility), and I have not verified the full text beyond the abstract; a challenger should quote its disclosure of complex stability to neutralize a teaching-away argument. The ISP Bulletin text also could not be independently retrieved — its 2004 date and PVP–H₂O₂ content are taken from the patent's own citation list, per the instruction to use this page's Prior Art section.

Primary source for prior-art citations: https://patents.google.com/patent/US10646419/en (Citations, Non-Patent Citations, and Similar Documents sections). Supplemental: https://patents.google.com/patent/US5894017 ; https://patents.google.com/patent/US4144211 ; https://patents.google.com/patent/EP1210062A2/en (AU 778,646 B2 family).

This is a technical obviousness assessment, not a legal opinion or a validity determination; independent verification of reference dates and contents against primary records is recommended.