Rennou™ Varnish is indicated for the relief of tooth hypersensitivity through the mechanical occlusion of dentinal tubules.
Device Story
Rennou™ Varnish is a professional-use, fluoride-free, rosin-based cavity varnish applied by clinicians to prepared tooth surfaces. The device consists of a flavored compound containing natural rosin, ethanol, xylitol, theobromine, calcium acetate, and sodium hydrogen phosphate. Upon application, the ethanol evaporates, leaving a rosin-based film that mechanically occludes open dentinal tubules to provide relief from tooth hypersensitivity. The varnish is supplied in unit-dose trays with applicators. By creating a physical barrier and facilitating mineral deposition, the device prevents restorative material penetration and reduces sensitivity. Clinical benefit is derived from the mechanical occlusion of tubules, verified via SEM analysis. The device is intended for use in a clinical setting by dental professionals.
Clinical Evidence
Bench testing only. Laboratory studies on molars and dentin specimens confirmed effective tubule occlusion, deep penetration, and smooth surface finish via SEM analysis. Biocompatibility testing per ISO 10993-5 and USP <87> demonstrated acceptable safety profiles.
Technological Characteristics
Rosin-based varnish; components include natural rosin, ethanol, xylitol, theobromine, calcium acetate, and sodium hydrogen phosphate. Form factor: unit-dose tray with applicator. Principle: mechanical occlusion of dentinal tubules via film formation. Biocompatibility: ISO 10993-5 and USP <87> compliant.
Indications for Use
Indicated for the relief of tooth hypersensitivity in patients requiring professional dental application for the mechanical occlusion of dentinal tubules.
Regulatory Classification
Identification
Cavity varnish is a device that consists of a compound intended to coat a prepared cavity of a tooth before insertion of restorative materials. The device is intended to prevent penetration of restorative materials, such as amalgam, into the dentinal tissue.
Special Controls
*Classification.* Class II (special controls). The device, when it is an external cleaning solution, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 872.9.
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FDA U.S. FOOD & DRUG ADMINISTRATION
May 27, 2025
Theodent, LLC
Andrew Fuselier
General Manager
1441 Canal Street
New Orleans, LA 70112
Re: K243777
Trade/Device Name: Rennou™ Varnish (3% / Spearmint); Rennou™ Varnish (3% / Strawberry); Rennou™ Varnish (3% / Cherry); Rennou™ Varnish (3% / Bubble Gum)
Regulation Number: 21 CFR 872.3260
Regulation Name: Cavity Varnish
Regulatory Class: Class II
Product Code: LBH
Dated: May 14, 2025
Received: May 15, 2025
Dear Andrew Fuselier:
We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
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K243777 - Andrew Fuselier
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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-
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K243777 - Andrew Fuselier
Page 3
assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
MICHAEL E. ADJODHA -S
Michael E. Adjodha, MChE, RAC, CQIA
Assistant Director
DHT1B: Division of Dental and ENT Devices
OHT1: Office of Ophthalmic, Anesthesia, Respiratory, ENT, and Dental Devices
Office of Product Evaluation and Quality
Center for Devices and Radiological Health
Enclosure
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FORM FDA 3881 (6/20)
Page 1 of 1
PSC Publishing Services (301) 443-6740
EF
| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 06/30/2023 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K1243777 | |
| Device Name Rennou™ Varnish (3% / Spearmint); Rennou™ Varnish (3% / Strawberry); Rennou™ Varnish (3% / Cherry); Rennou™ Varnish (3% / Bubble Gum) | |
| Indications for Use (Describe) Rennou™ Varnish is indicated for the relief of tooth hypersensitivity through the mechanical occlusion of dentinal tubules. | |
| Type of Use (Select one or both, as applicable) ☑ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |
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# RENNOU™ VARNISH 510(K) SUMMARY
## 1. SUBMITTER INFORMATION
Name: Theodent, LLC
Address: 1441 Canal Street
New Orleans, Louisiana 70112
Phone: (504) 264-5050 (504) 264-1885
Email: fuselier@theo-corp.com andrew@theo-corp.com
Contact: Joseph Fuselier Andrew Fuselier
Preparation Date: May 27, 2025
## 2. SUBMITTED DEVICE
Name of Device: Rennou™ Varnish
Classification Name: Cavity Varnish
Primary Product Code: 21 CFR 872.3260
Classification: Class II
Predicate Device: Colgate® Prevident Varnish (K132109)
## 3. DEVICE DESCRIPTION AND TECHNOLOGICAL CHARACTERISTICS
Rennou™ Varnish is a cavity varnish intended for professional use as a topical application on prepared tooth surfaces. This fluoride-free varnish creates a rosin-based film that prevents penetration of restorative material into the dentinal tissue and provides relief of tooth hypersensitivity by occluding open dentinal tubules. Unit-dose varnish and applicator are packaged together in individual thin, sealed trays. Rennou™ Varnish is only applied by a professional clinician.
Rennou™ Varnish is a topically applied flavored (Spearmint, etc.) compound comprised of natural rosin, ethanol, xylitol, and Rennou™ (a combination of theobromine, calcium acetate, and sodium hydrogen phosphate). The major components are rosin and ethanol, which, when delivered together, efficiently promote a fast-drying film on the tooth surface. The varnish is sweetened with xylitol.
1441 Canal Street, New Orleans, Louisiana 70112, United States
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4. INDICATIONS FOR USE
Rennou™ Varnish is indicated for the relief of tooth hypersensitivity through the mechanical occlusion of dentinal tubules.
5. TESTING SUMMARY
Comprehensive laboratory studies evaluated Rennou™ Varnish for performance and biocompatibility. Enamel protection and dentinal hypersensitivity tests on molars and dentin specimens showed effective tubule occlusion, deep penetration, and a smooth surface finish, confirmed by SEM analysis. Cytotoxicity testing per ISO 10993-5 and USP <87> showed acceptable biocompatibility, with Rennou™ Varnish exhibiting a slightly more favorable safety profile when tested directly against the primary predicate device. Additional testing was deemed unnecessary given the device's use of well-established rosin-based varnish technology in the market, documented safety of novel ingredients in dental applications, and substantial equivalence to predicates in both intended use and technological characteristics. The comprehensive risk analysis revealed no new questions of safety or effectiveness, as the device operates through the same mechanical principles as predicates while demonstrating a favorable safety profile, especially for children.
| | Rennou™ Varnish | Colgate Prevident Varnish | Colgate Desensitizing Mouthwash | Remedent NV Remesense | Ultradent Flor-Opal Varnish | Novamin Oralief Toothpaste | Comments |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Device | Submitted Device | Primary Predicate | Reference Device | Reference Device | Reference Device | Reference Device | Reference devices were included to highlight the various approved cavity varnishes containing novel ingredients for occlusion benefit. |
| 510(k) number | K243777 | K132109 | K140481 | K082594 | K080249 | K080228 | |
| Indication for use(abbreviated) | Treatment of dental hypersensitivity | Treatment of dental hypersensitivity | Treatment of dental hypersensitivity | Treatment of dental hypersensitivity | Treatment of dental hypersensitivity | Treatment of dental hypersensitivity | Indications for Use are consistent amongst all devices. |
| Product Design | Cavity varnish | Cavity varnish | Mouthwash | Foam Strips | Cavity Varnish | Toothpaste | While product designs differ amongst the devices, our product design is the same as the primary predicate device. |
| Chemical Composition | Rosin, Ethanol, Xylitol, Theobromine, Calcium Acetate, Sodium Hydrogen Phosphate, Flavor | Rosin, Ethanol, Xylitol, Sodium Fluoride, Hexadecane Phosphate, Citric Acid, Polysorbate 80, Sucralose, Flavor | Water, Glycerin, Sorbitol, Propylene Glycol, Tetrapotassium Pyrophosphate, PEG-40 Hydrogenated Castor Oil, L-Arginine, PVM/MA Copolymer, Polysorbate 20, Tetrasodium Pyrophosphate, Flavor, Benzyl Alcohol, Sodium Fluoride, Menthol, | Glycerin, Water, Dipotassium Oxalate, Flavor, EDTA, Methylparaben, Citric Acid and Saccharin | Rosin, Ethanol, Xylitol, Sodium Fluoride, Hexadecane Phosphate, Citric Acid, Polysorbate 80, Sucralose, Flavor | Calcium Sodium Phosphosilicate, Glycerin, Amorphous Silica, PEG-400, Titanium Dioxide, Sodium Lauryl Sulfate, Flavor, Carbomer, Potassium Acesulfame | Our chemical composition uses a rosin-based formulation for a mechanical occlusion of dentinal tubules, and also includes a novel ingredient to assist in the occlusion, just as the other cleared devices do. |
1441 Canal Street, New Orleans, Louisiana 70112, United States
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| | | | Sodium Saccharin, Citric Acid, Methylisothiazolinone, CI 42051, CI 17200 | | | | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| **Technological Characteristics** | Provides prolonged contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Provides prolonged contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Provides contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Provides contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Provides prolonged contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Provides contact of ingredients with tooth surface; forms protective barrier; releases minerals to enhance tooth structure. | Technologically, our submitted device has the same characteristics as the primary predicate and other reference devices. |
| **Biocompatibility** | Yes | Yes | Yes | Yes | Yes | Yes | Any differences between the subject and predicate/reference devices do not raise new safety concerns, as the materials and design are biocompatible and meet established safety standards validated through prior FDA evaluations. |
## 6. COMPARISON TO PREDICATE DEVICES
The table above summarizes how Rennou™ Varnish is substantially equivalent to the predicate devices in indication for use, product design, composition of material, technological characteristics, and biocompatibility.
## 7. CONCLUSION
In summary, this submission presents compelling evidence demonstrating that Rennou™ Varnish is substantially equivalent in both safety and effectiveness to its predicate devices. Rigorous testing has shown that Rennou™ Varnish occludes dentinal tubules at a level that meets or exceeds comparable products currently in clinical use. Strict adherence to ISO 10993-5 biocompatibility standards confirms that Rennou™ Varnish is safe when applied as directed by dental professionals.
The technological difference between Rennou™ Varnish and predicate varnishes resides in the formulation. Rennou™ varnish incorporates theobromine and calcium phosphate salts for occlusion benefits. Published scientific literature demonstrates that these ingredients can facilitate mineral deposition on the tooth surface, including the occlusion of dentin tubules. Many predicate cavity varnishes, such as Colgate’s Desensitizing Mouthwash with arginine or Novamin’s bioglass-containing toothpaste, are similar to the Rennou Varnish in that they contain such ingredients for this purpose.
Critically, this product maintains the established indications for use without introducing any new or unforeseen risks, thus preserving the status quo. The data provided in this submission robustly supports the conclusion that Rennou™ Varnish satisfies all criteria for substantial equivalence, ensuring its safe and effective integration into dental practice.
1441 Canal Street, New Orleans, Louisiana 70112, United States
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.