The LW Retraction Cap is intended for use with a dental implant to provide support for prosthetic restorations such as crowns, bridges, or overdentures.
Device Story
LW Retraction Cap is a dental component used to protect LW Solid and LW Vis abutments within the oral cavity. It is a temporary device used for up to 30 days. The device is provided non-sterile and must be sterilized by the clinician before use. It functions as a protective cover for the abutment during the healing or restorative process. The healthcare provider selects the appropriate size based on the compatible abutment and places it over the abutment in the clinic. By protecting the abutment, it facilitates the prosthetic restoration process, ultimately benefiting the patient by maintaining the integrity of the implant site during the transition to final restoration.
Clinical Evidence
No clinical data. Bench testing only. Testing included end-user sterilization validation per ISO 17665-1/2, biocompatibility (cytotoxicity) per ISO 10993-5, and performance testing for appearance and dimensions to ensure proper fit with compatible abutments.
Technological Characteristics
Material: POM (Polyoxymethylene) per ASTM F1855. Form factor: Cap/cover for dental abutments. Dimensions: Diameters 5.0-8.7 mm, Lengths 5.5-8.5 mm. Connectivity: None. Sterilization: Non-sterile, validated for end-user moist heat sterilization.
Indications for Use
Indicated for use with dental implants to support prosthetic restorations including crowns, bridges, or overdentures in patients requiring dental implant abutment protection.
Regulatory Classification
Identification
An endosseous dental implant abutment is a premanufactured prosthetic component directly connected to the endosseous dental implant and is intended for use as an aid in prosthetic rehabilitation.
Special Controls
*Classification.* Class II (special controls). The guidance document entitled “Class II Special Controls Guidance Document: Root-Form Endosseous Dental Implants and Endosseous Dental Implant Abutments” will serve as the special control. (See § 872.1(e) for the availability of this guidance document.)
{0}------------------------------------------------
Image /page/0/Picture/0 description: The image contains the logos of the Department of Health & Human Services and the Food and Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo includes the text "U.S. Food & Drug Administration" in blue letters.
9-14-23
Ossvis Co., Ltd. % April Lee Consultant Withus Group Inc. 106 Superior Irvine, California 92620
Re: K231079
Trade/Device Name: LW Retraction Cap Regulation Number: 21 CFR 872.3630 Regulation Name: Endosseous Dental Implant Abutment Regulatory Class: Class II Product Code: NHA Dated: August 11, 2023 Received: August 11, 2023
Dear April Lee:
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.
{1}------------------------------------------------
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 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-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 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.
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 medical devices and radiation-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.
Sherrill Lathrop Blitzer
for Andrew Steen 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) K231079
Device Name
LW Retraction Cap
Indications for Use (Describe)
The LW Retaction Cap is intended for use with a dental implant to provide support for prosthetic restorations such as crowns, bridges, or overdentures.
Type of Use (Select one or both, as applicable)
> Prescription Use (Part 21 CFR 801 Subpart D)
### 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."
Form Approved: OMB No. 0910-0120 Expiration Date: 06/30/2023 See PRA Statement below.
{3}------------------------------------------------
## 510(k) Summary
## Submitter
Ossvis Co., Ltd. Young Jae Kim 7F and B1, 38, Burim-ro 170beon-gil, Dongan-gu, Anyang-si, Gyeonggi-do, Republic of Korea Email: yjk@ossvis.com Tel. +82-31-360-0082 Fax. +82-31-360-0058
## Device Information
- Trade Name: LW Retraction Cap
- Common Name: Endosseous Dental Implant Abutment
- Classification Name: Abutment, Implant, Dental, Endosseous
- Product Code: NHA
- Panel: Dental
- Regulation Number: 21 CFR 872.3630
- Device Class: Class II
- . Date Prepared: 09/12/2023
## Predicate Devices:
The subject device is substantially equivalent to the following predicate devices:
- K161689, OSSTEM Implant System Abutment by OSSTEM Implant Co., Ltd. .
## Indication for Use:
The LW Retraction Cap is intended for use with a dental implant to provide support for prosthetic restorations such as crowns, bridges, or overdentures.
## Device Description:
The LW Retraction Cap is a component of the LW Implant System (K223924), and it is used with the LW Solid Abutment and LW Vis Abutment of the LW Implant System.
| Name | Uses | Surface Treatment |
|-------------------|---------------------------------------------------------------------------------|-------------------|
| LW Retraction Cap | Used to protect the LW Solid Abutment and LW Vis<br>Abutment in the oral cavity | N/A |
The LW Retraction Cap is made of POM(Polyoxymethylene(ASTM F1855)) and provided nonsterile, which is required to be sterilized by the end-user before use.
The dimensions of subject device are as following:
| No | Device Name | Dimension |
|----|-------------------|---------------------------------------------------------------------------|
| 1 | LW Retraction Cap | Ø 5.0, 6.0, 6.1, 6.7, 7.2, 7.7, 8.2, 8.7 mm<br>(D) x 5.5, 7.0, 8.5 mm (L) |
## Materials:
- LW Retraction Cap is fabricated from POM(Polyoxymethylene) of ASTM F1855 .
### Official Correspondent Withus Group Inc. April Lee 106 Superior, Irvine, CA 92620 USA Email: withus6664@gmail.com Phone: 1-909-274-9971 Fax: 1-909-460-8122
{4}------------------------------------------------
## Summaries of Technological Characteristics & Substantial Equivalence Discussion
### LW Retraction Cap
| | Subject Device | Predicate Device |
|-----------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 510(k) # | K231079 | K161689 |
| Device Name | LW Retraction Cap | OSSTEM Implant System - Abutment |
| Abutment Name | LW Retraction Cap | Rigid Retraction Cap |
| Manufacturer | Ossvis Co., Ltd. | OSSTEM Implant Co., Ltd. |
| Product Code | NHA | NHA |
| Regulation | 21 CFR 872.3630 | 21 CFR 872.3630 |
| Appearance | Image: LW Retraction Cap | Image: OSSTEM Implant System - Abutment |
| Indications for<br>Use Statement | The LW Retraction Cap is intended for use with a<br>dental implant to provide support for prosthetic<br>restorations such as crowns, bridges, or<br>overdentures. | The OSSTEM Implant System - Abutment is intended<br>for use with a dental implant to provide support for<br>prosthetic restorations such as crowns, bridges, or<br>overdentures. |
| Uses | Used to protect the LW Solid Abutment and LW Vis<br>Abutment in the oral cavity | Used for the protection of the Rigid Abutment on the<br>oral cavity |
| Diameter (mm) | 5.0, 6.0, 6.1, 6.7, 7.2, 7.7, 8.2, 8.7 | 4.8, 6.0, 6.6, 7.7, 8.7 |
| Length (mm) | 5.5, 7.0, 8.5 | 5.5, 7.0, 8.5 |
| Material | POM (Polyoxymethylene)<br>(ASTM F1855) | POM (Polyoxymethylene)<br>(ASTM F1855) |
| Sterilization | N/A | N/A |
| Surface treatment | N/A | N/A |
| Maximum<br>duration for<br>clinical use | 30 days | Unknown |
| Substantial Equivalence Discussion | | |
The LW Retraction Cap has the same indication for use, material, design feature, surface treatment, and sterilization as the primary predicate.
The difference between the subject and primary predicate is difference does not raise any serious issues in performance or safety because it is used temporarily in the oral cavity and the size fits its compatible abutment considering the intended use of the device. Therefore, the subject device is substantial equivalence to the predicate device.
{5}------------------------------------------------
## Non-Clinical Test Data
The following non-clinical tests were conducted to prove the safety and performance of the LW Retraction Cap.
#### . End User Sterilization Validation
The subject device is delivered non-sterile and is intended to be sterilized by the end user. The recommended sterilization conditions have been validated by performing the end-user sterilization validation according to ISO 17665-1 "Sterilization of health care products – Moist heat – part 1: Requirements for the development, validation, and routine control of a sterilization process for medical devices" and ISO 17665-2 "Sterilization of health care products – Moist heat – part 2: Guidance on the application of ISO 17665-1 ". The worst-case scenario was considered in the test, and the results showed equivalency to the predicate device.
#### . Biocompatibility Tests
Cytotoxicity Testing was performed according to ISO 10993-5 and to the FDA Guidance document, "Use of International Standard ISO 10993-1, 'Biological evaluation of medical devices- Part 1: Evaluation and testing within a risk management process', Guidance for Industry and Food and Drug Administration Staff".
#### Performance Tests .
Tests for appearance and dimensions were performed to evaluate the performance of the LW Retraction Cap. The test results satisfied the acceptance criteria and support that the device will fit its compatible abutment and function properly as its intended use, which is to cover and protect an abutment.
The non-clinical testing results have met the acceptance criteria and demonstrated the substantial equivalence with the predicate device.
## Conclusion
The documentation submitted in this premarket notification demonstrates the LW Retraction Cap is substantially equivalent to the primary predicate device.
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.