Flexible Block is a circular solid (disc) or rectangular solid (block) made from polyamide through high-temperature injection molding, and is used in a CAD/CAM milling machine for production of dental plates, bite plates, frame-works, clasps, personal trays, appliances, occlusal night guards. These blocks are available in a variety of shapes and sizes for different milling systems and in a variety of dental shades.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study information for the Flexible Block device, based on the provided FDA 510(k) summary:

This device is a material (dental polymer blanks) used in a CAD/CAM milling machine to create dental restorations, not a diagnostic AI device. Therefore, many of the typical AI acceptance criteria and study components (like expert ground truth, adjudication, MRMC studies, standalone algorithm performance, and training set details) are not applicable. The "acceptance criteria" here refer to the product's physical, chemical, and biological properties meeting established standards for similar dental materials.

1. A table of acceptance criteria and the reported device performance

Comparison Item / Acceptance Criteria	New Device (Flexible Block) Performance	Predicate Device (Perflex Biosens K150454)
Material Composition	Polyamide	Super polyamide, thermoplastic compound
Tensile strength (based on ASTM D638)	≥ 30 Mpa (The document states "Tensile strength: ≥30Mpa" as a reported property, implying this is the performance and implicitly the acceptance criteria for this specific property based on comparison to the predicate and relevant standards)	(Not explicitly stated for predicate in table, but overall comparison indicates compliance with relevant standards)
Elongation at break (based on ASTM D638)	≥ 40% (Similar to tensile strength, this is a reported property implying acceptance criteria)	(Not explicitly stated for predicate)
Water absorption (based on ASTM D570)	≤ 5% (Similar to tensile strength, this is a reported property implying acceptance criteria)	(Not explicitly stated for predicate)
Impact strength (based on ASTM D256)	≥ 20 KJ/m² (Similar to tensile strength, this is a reported property implying acceptance criteria)	(Not explicitly stated for predicate)
Flexural strength (based on ASTM D790)	≥ 30 Mpa (Similar to tensile strength, this is a reported property implying acceptance criteria)	(Not explicitly stated for predicate)
Flexural modulus (based on ASTM D790)	≥ 1000 Mpa (Similar to tensile strength, this is a reported property implying acceptance criteria)	(Not explicitly stated for predicate)
Biocompatibility (ISO 10993 standards) - Non genotoxicity (ISO 10993-3) - Non cytotoxicity (ISO 10993-5) - Non sensitization or irritation (ISO 10993-10) - Non systemic toxicity (ISO 10993-11)	Met (Biocompatibility tests performed and "satisfy the ISO 10993 standards," including systemic toxicity, skin irritation, skin sensitization, in vitro cytotoxicity, in vitro mammalian cell TK gene mutation test, in vitro mammalian chromosome aberration test, and bacterial reverse mutation study)	NA (Predicate "Flexible Block" stated as "NA" for specific 10993 tests in the comparison table, but overall assumed biocompatible as a marketed device.)
Regulatory Classifications	Class II	Class II
Indications for Use	Similar (Intended for making dental plates, bite plates, frame-works, clasps, personal trays, appliances, occlusal splints and night guards.)	Similar (for making dental plates, bite plates, frame-works, clasps, personal trays, appliances, occlusal splints and night guards)
Contraindications	Same	Same
Labeling	Similar	Similar
Target Population	Dental patients	Dental patients
Anatomical Site	On teeth	On teeth
Where Used	Hospital, dental clinic, and relevant places	Hospital, dental clinic, and relevant places
Human Factors	Dental professional	Dental professional
Design	Circular solid (disc) or rectangular solid (block) of polyamide.	Circular solid (disc) or rectangular solid (block) of super polyamide and thermoplastic compound.
Cautions	Similar	Similar
Standards Met	Same (implicitly, by meeting specific ASTM and ISO standards)	Same (implicitly, by meeting specific ASTM and ISO standards)
Sterility	Non-sterile	Non-sterile
Chemical Safety	Similar	Similar

Study to prove acceptance criteria:

The study performed was a series of bench tests to evaluate the physical, chemical, and biological properties of the Flexible Block device.

2. Sample size used for the test set and the data provenance

Sample Size: Not explicitly stated in terms of number of blocks tested for each physical property. However, it mentions "We selected our Flexible Block (Model: monolayer; Specification: 98×20mm; Shade: Clear) as the representative in biocompatibility tests," implying a single representative model was used for biocompatibility.
Data Provenance: The tests were conducted by the manufacturer, Shandong Huge Dental Material Corporation, based in China ("No. 68 Shanhai Road, Donggang District Rizhao City, Shandong 276800 China"). This is a retrospective evaluation of a newly manufactured material against established standards.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

Not Applicable. For a material device, "ground truth" is established by adherence to physical, chemical, and biological standards (e.g., ASTM, ISO). There are no human "experts" establishing ground truth in the context of diagnostic performance here. The "experts" would be the personnel in the testing laboratories who perform the tests according to the specified standards.

4. Adjudication method for the test set

Not Applicable. There is no adjudication method in the context of evaluating a material against objective physical and chemical standards.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not Applicable. This is a material device, not an AI-enabled diagnostic tool. No MRMC study was performed.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not Applicable. This is a material device, not an algorithm.

7. The type of ground truth used

The "ground truth" for this device is based on established material science standards (e.g., ASTM D638, ASTM D570, ASTM D256, ASTM D790) for physical properties, and international biocompatibility standards (ISO 10993 series) for biological safety.

8. The sample size for the training set

Not Applicable. This is a material device, not a machine learning model. There is no concept of a "training set" in this context. The manufacturing process of the material could be seen as analogous to a "training set" in a very abstract sense (optimizing the material's properties), but it does not use a data-driven training set like AI models.

9. How the ground truth for the training set was established

Not Applicable. As there is no training set for an AI model, there is no ground truth established for it. The development of the material's properties would be based on material science principles and iterative testing against target performance specifications.

Summary

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March 4, 2022

Shandong Huge Dental Material Corporation Maggie Zheng Regulatory Affairs Manager No. 68 Shanhai Road, Donggang District Rizhao City, Shandong 276800 China

Re: K213994

Trade/Device Name: Flexible Block Regulation Number: 21 CFR 872.3760 Regulation Name: Denture Relining, Repairing, Or Rebasing Resin Regulatory Class: Class II Product Code: EBI, MQC Dated: December 15, 2021 Received: December 21, 2021

Dear Maggie Zheng:

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 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

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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,

For 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

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Indications for Use

510(k) Number (if known) K213994

Device Name Flexible Block

Indications for Use (Describe)

Intended for making dental plates, bite plates, frame-works, clasps,personal trays, appliances, occlusal splints and night guards.

Type of Use (Select one or both, as applicable)

X Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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510 (k) Summary K213994

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of 21 C.F.R. 807.92.

1. Date Summary Prepared: Feb. 18, 2022

2. Submitter Information:

Name	Shandong Huge Dental Material Corporation
Address	No. 68 Shanghai Road, Donggang District, Rizhao City, ShandongProvince, 276800, P.R. China
Telephone	086-633-2277268
Fax	086-633-2277298
Contact Person	Ms. Maggie Zheng
Contact Title	Regulatory Affairs Manager
E-mail	zhengxy@hugedent.com

3. Device Name

Trade name: Flexible Block Common name: Dental polymer blanks (discs or blocks) Classification name: Resin, Denture, Relining, Repairing, Rebasing (21 C.F.R. 872.3760) Regulatory Class: II Product Code: EBI, MQC

4. Substantially Equivalent Device

Company Name	Device Name	510 (k) NO.	SubstantiallyEquivalent (SE)Decision Date	Product code
PERFLEX	Perflex Biosens	K150454	05/26/2015	EBI, MQC

This predicate device have not been subject to a design-related recall.

5. Description of Device

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night guards. These blocks are available in a variety of shapes and sizes for different milling systems and in a variety of dental shades.

6. Intended use

Patient populations: Patients need dental restorations in dental therapy.

Target user group: Use by health care professional or dentist.

Indications for use: Intended for making dental plates, frame-works, clasps, personal trays, appliances, occlusal splints and night guards.

7. Summary of Physical and Chemical Properties Tests

Chemical Composition:
The device is made from polyamide.
Technological characteristics:
The device has the same technological characteristics as the predicate device (Perflex Biosens). And the device is similar in sizes, shapes and shades as the predicate devices.
Properties:
The device has comparable physical and chemical properties as the predicate device.
Applications: ●
The device has similar indications for use as the sum of the predicate devices: Intended for making dental plates, bite plates, frame-works, clasps,personal trays, appliances, occlusal splints and night guards by CAD/CAM.

8. Technological Characteristics:

The new device, Flexible Block, has the same design, materials and chemical composition as the predicate device.

Bench tests were performed on the new device including the items listed in the table below. The test results indicated that the new device meets the pass/fail criteria and supports substantial equivalence when compared to the predicate device on physical properties.

Comparison Items	New Device	Predicate Device
	FlexibleBlock	Perflex BiosensK150454
1) RegulatoryClassifications	same	same
2) Indications foruse	similar	similar
3) Contraindications	same	same
4) Composition ofMaterials	Polyamide	super polyamide, thermoplasticcompound

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Comparison Items	New Device				Predicate Device
	Flexible Block				Perflex Biosens
						K150454
5) PhysicalProperties	Physicalparameters	Tensilestrength:≥30Mpa	Elongation atbreak:≥40%	Waterabsorption:≤5%	Impactstrength:≥20KJ/m2		Flexuralstrength:≥30Mpa	Flexuralmodulus:≥1000Mpa
	Inspectionmethodbasis	ASTMD638	ASTMD638	ASTMD570	ASTM D256		ASTMD790	ASTM D790
6) Labeling	similar				similar
7) TargetPopulation	dental patients				dental patients
8) Anatomical Site	on teeth				on teeth
9) Where Used	used in hospital, dental clinic andrelevant places				used in hospital, dental clinic and relevant places
10) Human Factors	dental professional				dental professional
11) Design	Circular solid (disc) or rectangularsolid (block) of polyamide.				Circular solid (disc) or rectangular solid (block) ofsuper polyamide and thermoplastic compound.
12) Cautions	similar				similar
13) Standards Met	same				same
14) Biocompatibility	ISO 10993-3Non genotoxocityISO 10993-5Non cytotoxicityISO 10993-10Non sensitization or irritationISO 10993-11Non systemic toxicity				NA
15) Sterility	Non-sterile				Non-sterile
16) Chemical Safety	similar				similar

The new device has highly similar indications for use as predicate device: both devices are to make dental plate, bite plates, personal trays, appliances, occlusal splints and night guards. The difference between the indications don't raise different questions of safety and effectiveness.

9. Summary of Biocompatibility

The new device, Flexible Block, is substantially equivalent to the predicate devices that have been on the market for years without any clinical adverse events. The formulation of new device does not contain any new or non-conventional chemicals compared to the legally marketed predicate device.

We selected our Flexible Block (Model: monolayer; Specification: 98×20mm; Shade: Clear) as the representative in biocompatibility tests and those biocompatibility test reports can be used in the biological evaluation of Flexible Block.

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Biocompatibility tests were performed to satisfy the ISO 10993 standards. The test items include Systemic Toxicity; Skin Irritation; Skin Sensitization; In Vitro Cytotoxicity; In Vitro Mammalian Cell TK Gene Mutation Test; In Vitro mammalian chromosome aberration test and Bacterial reverse mutation study.

10. Clinical Performance Data

Not applicable. Clinical performance testing has not been performed for the subject device as it has not been marketed in any area.

11. Summary of Substantial Equivalence

As with the comparison shown in substantial equivalence discussion, these devices are same or similar in almost all aspects. The details of physical properties are slightly different, but these two devices are in compliance with the relevant standards.

It can be seen that the minor differences between the new device and the predicate device are not of significance and do not raise questions of safety and effectiveness as compared to the predicate device. We conclude that Flexible Block is substantially equivalent to the predicate device described herein.

Regulation Number and Section

§ 872.3760 Denture relining, repairing, or rebasing resin.

(a)
Identification. A denture relining, repairing, or rebasing resin is a device composed of materials such as methylmethacrylate, intended to reline a denture surface that contacts tissue, to repair a fractured denture, or to form a new denture base. This device is not available for over-the-counter (OTC) use.(b)
Classification. Class II.