APAPRO Desensitizer is a fluoride-free paste that is indicated to provide relief from tooth hypersensitivity resulting from cold, heat, acids, sweets, or contact, through its action of dentin tubule occlusion. APAPRO Desensitizer is intended to be prescribed and applied by dental physicians for use in the Adult Population.
Device Story
APAPRO Desensitizer is a fluoride-free paste containing 20% w/w synthetic hydroxyapatite; applied by dental professionals in a clinical setting. Device functions by physically depositing hydroxyapatite onto tooth surfaces to occlude exposed dentin tubules; acts as a template for further deposition of calcium and phosphate ions to promote crystal integrity. Output is the physical occlusion of tubules, which desensitizes teeth and provides relief from sensitivity triggers. Clinical benefit is the reduction of pain associated with tooth hypersensitivity.
Clinical Evidence
Bench testing only. Non-clinical SEM micrographs compared dentin samples treated with APAPRO Desensitizer against those treated with the predicate (NovaMin). Results showed similar physical occlusion of dentin tubules via hydroxyapatite layer deposition, demonstrating comparable effectiveness.
Technological Characteristics
Fluoride-free paste containing 20% w/w synthetic hydroxyapatite. Mode of action: physical occlusion of dentin tubules via hydroxyapatite deposition. Supplied non-sterile. Biocompatibility assessed per ISO 10993.
Indications for Use
Indicated for adult patients experiencing tooth hypersensitivity due to cold, heat, acids, sweets, or contact.
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.
{0}------------------------------------------------
Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: a symbol on the left and the FDA name and title on the right. The symbol on the left is a stylized representation of a human figure, while the text on the right reads "FDA U.S. FOOD & DRUG ADMINISTRATION" in blue letters.
February 16, 2022
Sangi Co, Ltd % Dave Yungvirt CEO Third Party Review Group, LLC 25 Independence Blvd Warren, New Jersey 07059
Re: K220419
Trade/Device Name: Apapro Desensitizer Regulation Number: 21 CFR 872.3260 Regulation Name: Cavity varnish Regulatory Class: Class II Product Code: LBH Dated: February 7, 2022 Received: February 14, 2022
Dear Dave Yungvirt:
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 (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 located 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.
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
{1}------------------------------------------------
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 of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-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 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/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-device-advice-comprehensive-regulatoryassistance/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, M.ChE. 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
{2}------------------------------------------------
# Indications for Use
510(k) Number (if known) K220419
Device Name APAPRO Desensitizer
Indications for Use (Describe)
APAPRO Desensitizer is a fluoride-free paste that is indicated to provide relief from tooth hypersensitivity resulting from cold, heat, acids, sweets, or contact, through its action of dentin tubule occlusion.
X 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."
{3}------------------------------------------------
### K220419
Image /page/3/Picture/2 description: The image is a logo for SANGI. The logo is a purple square with three horizontal white lines inside. Below the lines, the word "SANGI" is written in white, block letters.
SANGI CO., LTD., 3-11-6 TSUKIJI, CHUO-KU, TOKYO 104-8440, JAPAN TEL. +81 70-2680-2931 FAX. +81 3--3543-3651
Submitter Information:
| Name: | Sangi Co., Ltd. |
|-------------------|-----------------------------------------------|
| Address: | 3-11-6 Tsukiji, Chuo-ku, Tokyo 104-8440 Japan |
| Phone: | +81 70-2680-2931 |
| Facsimile: | +81 3-3543-3651 |
| Contact Person: | Douglas Mercadante |
| Preparation Date: | 12 May 2021 |
- 1. Device Nomenclature:
| Trade Name: | APAPRO Desensitizer |
|----------------------|--------------------------------------------------|
| Common Name: | Tooth Desensitizing Paste |
| Classification Name: | Cavity Varnish (21 CFR 872.326 Product code LBH) |
- 2. Legally Marketed Predicate Device:
| Device Name: | OraliefTM Therapy for Sensitive Teeth |
|----------------|---------------------------------------|
| 510(k) Number: | K040858 |
| Applicant: | NovaMin Technology, Inc. |
- 3. Device Description:
APAPRO Desensitizer is a fluoride-free tooth desensitizing paste that utilizes hydroxyapatite, the main component of teeth, as its active ingredient to relieve tooth sensitivity by physically occluding exposed dentin tubules. The hydroxyapatite deposited into dentin tubules by APAPRO Desensitizer then acts as a template for the further deposition of large amounts of calcium and phosphate ions, promoting crystal integrity and growth.
{4}------------------------------------------------
Sangi Co., Ltd. Traditional 510(k) APAPRO Desensitizer
- 4. Indications for Use
APAPRO Desensitizer is a fluoride-free paste that is indicated to provide relief from tooth hypersensitivity resulting from cold, heat, acids, sweets, or contact, through its action of dentin tubule occlusion.
- 5. Intended Use
APAPRO Desensitizer is a fluoride-free paste that is indicated to provide relief from tooth hypersensitivity resulting from cold, heat, acids, sweets, or contact, through its action of dentin tubule occlusion. APAPRO Desensitizer is intended to be prescribed and applied by dental physicians for use in the Adult Population.
- 6. Technological Characteristics:
Both APAPRO Desensitizer and the selected predicate device Oralief™ Therapy for Sensitive Teeth are intended to be used to treat the same disorder, namely for tooth hypersensitivity, by the same mode of action, which is the deposition of a calcium hydroxyapatite layer onto the tooth surface resulting in the physical occlusion of dentin tubules. The two devices differ in that Oralief The Therapy for Sensitive Teeth uses calcium sodium phosphosilicate (NovaMin®) as its active ingredient, which when introduced to the physiological fluid of the mouth, reacts to form a hydroxycarbonate apatite layer on the teeth, whereas APAPRO Desensitizer introduces synthetic hydroxyapatite directly onto the tooth surface. APAPRO Desensitizer is to be prescribed and applied by a dental professional. Oralief Therapy for Sensitive Teeth is also a home-use device to be prescribed by dental professionals.
- 7. Safety and Performance Data:
The ability of APAPRO Desensitizer to provide relief from tooth hypersensitivity was shown by non-clinical tests demonstrating that it physically occludes exposed dentin tubules. The SEM micrographs of dentin samples with tubules occluded by APAPRO Desensitizer were compared to SEM Micrographs of NovaMintreated dentin samples. The SEM Micrographs of APAPRO Desensitizer and NovaMin-treated samples showed similar occlusion of the dentin tubules, which was achieved in both cases by the deposition of a hydroxyapatite layer onto the surface of the tooth. Thus APAPRO Desensitizer was shown to be as effective as the NovaMin® found in the predicate device in occluding dentin tubules.
| Trait | APAPRO Desensitizer<br>New Device | Oralief™ Therapy for<br>Sensitive Teeth<br>Predicate Device | Equivalence<br>Determination |
|---------------------------|-----------------------------------|-------------------------------------------------------------|------------------------------|
| 510(k) Number | TBD | K040858 | N/A |
| Classification<br>Number | 872.3260 | 872.3260 | Equivalent |
| Product Code | LBH | LBH | Equivalent |
| Product<br>Classification | Class II | Class II | Equivalent |
- 8. Device Comparison Table:
{5}------------------------------------------------
## Sangi Co., Ltd. Traditional 510(k) APAPRO Desensitizer
| Prescription/<br>Over-the-<br>counter use | Prescription | Prescription | Equivalent |
|-----------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------|
| Intended Use | For dental hypersensitivity relief | For dental hypersensitivity relief | Equivalent |
| Indications for<br>Use | Provides rapid and continual relief<br>from tooth hypersensitivity due to<br>cold, heat, acids, sweets, or<br>contact through its action of the<br>occlusion of dentin tubules. | Provides rapid and continual<br>relief from tooth hypersensitivity<br>due to cold, heat, acids, sweets,<br>or contact through its action of<br>the occlusion of dentin tubules. | Equivalent |
| Active<br>Ingredient | 20% w/w Calcium Phosphate<br>(Hydroxyapatite) | 7.5% w/w Calcium Sodium<br>Phosphosilicate (NovaMin®) | Equivalent* |
| Device Action | APAPRO Desensitizer directly<br>occludes dentin tubules by<br>depositing a crystalline calcium<br>phosphate layer on the tooth<br>surface (i.e. hydroxyapatite). | The NovaMin® particles react<br>with the user's saliva to release<br>calcium and phosphate ions,<br>which precipitate onto the tooth<br>surface as a crystalline calcium<br>phosphate layer (i.e.<br>hydroxycarbonate apatite). | Equivalent |
| Material<br>Produced to<br>Occlude<br>Tubules | Hydroxyapatite | Hydroxycarbonate Apatite | Equivalent* |
| Performance | The hydroxyapatite layer occludes<br>exposed dentin tubules, which<br>results in desensitization. | The hydroxycarbonate apatite<br>layer occludes exposed dentin<br>tubules, which results in<br>desensitization. | Equivalent |
| Biocompatibility | Biocompatible, non-antigenic | Biocompatible, non-antigenic | Equivalent |
| Sterility | Supplied non-sterile | Supplied non-sterile | Equivalent |
*Details are provided in Section 12
- 9. Biocompatibility
Biocompatibility tests in accordance with ISO 10993 have been performed on APAPRO Desensitizer. A biological risk assessment, captured in the enclosed Biological Evaluation Report, has also been performed and included in this Traditional 510(k) application package. The biocompatibility assessment indicated that APAPRO Desensitizer has no hazardous effects to the consumer when used as directed in the Adult Population.
- 10. Conclusions:
{6}------------------------------------------------
Sangi Co., Ltd. Traditional 510(k) APAPRO Desensitizer
APAPRO Desensitizer is considered to be substantially equivalent to the legally marketed predicate device, Oralief™ Therapy for Sensitive Teeth. Both products are indicated for the relief of tooth hypersensitivity through the occlusion of dentin tubules. Both products achieve this by producing a calcium hydroxyapatite layer on the tooth surface. Additionally, both products have been shown to have comparable effectiveness with regards to tubule occlusion. No additional safety concerns have been observed when comparing APAPRO Desensitizer to Oralief™ Therapy for Sensitive Teeth.
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.