Denture Base Resins - Performance Criteria for Safety and Performance Based Pathway: Guidance for Industry and Food and Drug Administration Staff

Administrative guidance, not enacted legislation. This captured publisher edition preserves the listed document and attachments; later developments are not independently consolidated.

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Denture Base Resins – Performance
Criteria for Safety and Performance
Based Pathway
Guidance for Industry and
Food and Drug Administration Staff
Document issued on April 13, 2022.
The draft of this document was issued on August 30, 2021.
For questions about this document, contact OHT1/DHT1B: Division of Dental and ENT Devices
at 301-796-5620.
U.S. Department of Health and Human Services
Food and Drug Administration
Center for Devices and Radiological Health

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Preface
Public Comment
You may submit electronic comments and suggestions at any time for Agency consideration to
https://www.regulations.gov. Submit written comments to the Dockets Management Staff, Food
and Drug Administration, 5630 Fishers Lane, Room 1061, (HFA-305), Rockville, MD 20852.
Identify all comments with the docket number FDA-2021-D-0603. Comments may not be acted
upon by the Agency until the document is next revised or updated.
Additional Copies
Additional copies are available from the Internet. You may also send an email request to CDRH-
Guidance@fda.hhs.gov to receive a copy of the guidance. Please include the document number
20001 and complete title of the guidance in the request.

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1
Denture Base Resins – Performance
Criteria for Safety and Performance
Based Pathway
Guidance for Industry and
Food and Drug Administration Staff
This guidance represents the current thinking of the Food and Drug Administration (FDA or
Agency) on this topic. It does not establish any rights for any person and is not binding on
FDA or the public. You can use an alternative approach if it satisfies the requirements of the
applicable statutes and regulations. To discuss an alternative approach, contact the FDA staff
or Office responsible for this guidance as listed on the title page.
I. Introduction
This guidance provides performance criteria for denture base resins in support of the Safety and
Performance Based Pathway.1 Under this framework, submitters (you) planning to submit a
510(k) using the Safety and Performance Based Pathway for denture base resins will have the
option to use the performance criteria proposed in this guidance to support substantial
equivalence, rather than a direct comparison of the performance of the subject device to that of a
predicate device.
For the current edition of the FDA-recognized consensus standard(s) referenced in this
document, see the FDA Recognized Consensus Standards Database.2 For more information
regarding use of consensus standards in regulatory submissions, please refer to the FDA
guidance titled Appropriate Use of Voluntary Consensus Standards in Premarket Submissions
for Medical Devices.3
The contents of this document do not have the force and effect of law and are not meant to bind
the public in any way, unless specifically incorporated into a contract. This document is intended
only to provide clarity to the public regarding existing requirements under the law. FDA
guidance documents, including this guidance, should be viewed only as recommendations, unless
1 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/safety-and-performance-
based-pathway
2 Available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfStandards/search.cfm
3 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/appropriate-use-
voluntary-consensus-standards-premarket-submissions-medical-devices

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specific regulatory or statutory requirements are cited. The use of the word should in Agency
guidance means that something is suggested or recommended, but not required.
II. Scope/Device Description
Devices that are the subject this guidance are denture base resins. These devices are Class II and
are regulated under 21 CFR 872.3760, Denture relining, repairing, or rebasing resin, with the
product code EBI.
Intended Use/Indications for Use:
The prosthetic devices that fall within the scope of this guidance are for denture rebasing resin
composed of materials such as methyl methacrylate, intended to reline a denture surface that
contacts tissue, to repair a fractured denture, or to form a new denture base. These devices are
not available for over-the-counter (OTC) use.
These devices are intended for the fabrication of patient-specific denture bases for full or partial
dentures. The scope of this guidance does not include resins for OTC relining or repairing
denture bases, preformed denture teeth, or partially fabricated denture kits which are classified
elsewhere (see 21 CFR 872.3560, 872.3570, 872.3580, 872.3590 and 872.3600, respectively).
The following types and classes of polymers/materials (Types 1-5) are within the scope of this
guidance and are defined in the FDA-recognized consensus standard ISO 20795-1 Dentistry –
Base polymers – Part 1: Denture base polymers:
· Type 1: Heat-polymerizable materials
o Class 1: Powder and liquid
o Class 2: Plastic cake
· Type 2: Autopolymerizable materials
o Class 1: Powder and liquid
o Class 2: Powder and liquid for pour-type resins
· Type 3: Thermoplastic blank or powder
· Type 4: Light-activated materials
· Type 5: Microwave cured materials
Device Design Characteristics:
The performance criteria in this guidance are applicable to the classes of resins (Types 1-5).
Additively Manufactured Denture Resins:
For additively manufactured (3D printed) denture resins, we recommend that you reference
FDA’s guidance Technical Considerations for Additive Manufactured Medical Devices.4
additional information, not specifically addressed in ISO 20795-1, should be included in a
premarket submission. This includes:
4 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/technical-considerations-
additive-manufactured-medical-devices

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· identification of each workflow and system(s) (e.g., the specific scanner, software,
printer, cure unit, etc., employed) that is validated together for interoperability for
fabricating the device;
· identification of a compatible, legally marketed bonding agent needed to affix the device
to preformed denture teeth;
· if applicable, identification of a legally marketed resin for repairing the device and
instructions if in need of relining or repair;
· printing parameters (e.g., addition of support material, slicing, build path, instantaneous
power of energy delivery system, environmental conditions, etc.);
· as additive manufacturing allows different print directions within the build space relative
to the device/part orientation and/or to print more than one device/part simultaneously at
different build plate locations, identification of the build volume placement (e.g.,
acceptable part orientation, build plate location, and other parametric considerations) and
build repeatability manufacturing process information validated under your acceptance
activities to ensure reproducibility and consistency within a build cycle and across print
run lots;
· if applicable, leftover material reuse process for the validated additive manufacturing
method. This may include, but is not be limited to, a limit for number of print runs for
using leftover reused material, limit to percent of leftover reused material (for example
1:1 mixture of virgin and leftover reused materials), recycling processes such as filtering
leftover material, or monitoring for changes in chemistry, water content, etc.;
· instructions for the end user (if fabricated at point-of-care, e.g., dental laboratory or
office), including information on setup and on-site validation, reuse of leftover resin
material between print runs, and cleaning after final device printing;
· a verification and validation report of dimensional measurements demonstrating that the
physical output of the system for fabricating the device meets design input specifications
for critical dimensions within pre-specified tolerances for the device type and intended
use to demonstrate consistency and reproducibility between build cycles made on
samples from multiple build cycles; and
· performance testing considerations for additively manufactured devices (see Section III
below).
FDA may determine, on a case-by-case basis, that additional data are necessary to evaluate
whether the device is appropriate for the Safety and Performance Based Pathway. In situations
where you determine that additional testing outside of those identified in this guidance are
necessary to determine whether the device is appropriate for the Safety and Performance Based
Pathway, we would encourage you to submit a Pre-Submission5 to engage in discussion with
FDA prior to submission of the 510(k).
III. Testing Performance Criteria
If your device is appropriate for submission through the Safety and Performance Based Pathway,
and you choose to use that option, we do not expect you to provide direct comparison testing
5 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/requests-feedback-and-
meetings-medical-device-submissions-q-submission-program

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against a legally marketed predicate device to demonstrate substantially equivalent performance
characteristics. To ensure that the performance criteria outlined in this guidance remain
contemporary and take into account relevant data from recent clearances, FDA recommends that
you provide a results summary for all tests evaluated in addition to the other submission
information (e.g., Declaration of Conformity (DoC)) recommended below for each test or
evaluation. Consistent with FDA policy for all 510(k) submissions, for all 510(k) submissions
under the Safety and Performance Based Pathway, FDA may request and review underlying data
demonstrating that a new device meets the FDA-identified performance criteria and testing
methodology, as necessary. Unless otherwise identified in the sections below, test information
such as results summary, test protocols, or complete test reports should be submitted as part of
the 510(k) as described in FDA’s guidance Safety and Performance Based Pathway.6 For
additional information regarding the submission of non-clinical bench testing information, refer
to FDA’s guidance Recommended Content and Format of Non-Clinical Bench Performance
Testing Information in Premarket Submissions.7
Mechanical Bench Testing
1. Test name: Ultimate flexural strength
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria:
Types 1, 3, 4, and 5 polymers: ≥ 65 MPa
Type 2 polymers: ≥ 60 MPa
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
2. Test name: Flexural modulus
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria:
Types 1, 3, 4, and 5 polymers: ≥ 2000 MPa
Type 2 polymers: ≥ 1500 MPa
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
3. Test name: Stress intensity factor
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria: Types 1-5 polymers: ≥ 1.9 MPa • m1/2
6 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/safety-and-performance-
based-pathway
7 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/recommended-content-
and-format-non-clinical-bench-performance-testing-information-premarket

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Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
4. Test name: Fracture work
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria: Types 1-5 polymers: ≥ 900 J/m2
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
5. Test name: Residual monomer
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria:
Types 1, 3, 4, and 5 polymers: ≤ 2.2% mass fraction of methyl methacrylate
Type 2 polymers: ≤ 4.5% mass faction of methyl methacrylate
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
6. Test name: Water sorption
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria: Types 1-5 polymers: ≤ 32 μg/mm3
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
7. Test name: Water solubility
Methodology: FDA-recognized version ISO 20795-1 Dentistry – Base polymers – Part
1: Denture base polymers
Performance Criteria:
Types 1, 3, 4, and 5 polymers: ≤ 1.6 μg/mm3
Type 2 polymers: ≤ 8 μg/mm3
Performance Criteria Source: FDA-recognized version ISO 20795-1 (2013) Dentistry
– Base polymers – Part 1: Denture base polymers
Submission Information: DoC
Additive Manufacturing Testing Considerations
The performance criteria above also apply to additively manufactured denture base resins.
The following tests are based on a loading force directionally applied to the devices and the
evaluation of resulting failure modes:

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· ultimate flexural strength;
· flexural modulus;
· stress intensity factor; and
· fracture work.
Therefore, performance testing for additively manufactured devices should additionally account
for the layer-by-layer process of additive manufacturing where the imparted directionality from
the printing process (i.e., anisotropy) may affect the final device properties. You should assess
the variability of mechanical performance under loading across the multiple device
configurations available based on the build volume placement (e.g., part orientation, build plate
location, and other parametric considerations) and leftover material reuse parameters, as
described in Section II. For these four bulleted mechanical bench tests above, we recommend
you provide testing that evaluates clinically relevant worst-case scenarios for build orientation
based on available print directions (e.g., x, y, or z-axis), build plate locations (e.g., center vs.
corner), and leftover material reuse procedures (if applicable) to show the final printed device
properties remain within pre-specified ranges. The number of test runs or build cycles will be
dependent on your printing strategy and worst-case analysis.
For the following three tests, the layer-by-layer process of additive manufacturing is not
expected to affect test result variability and a loading force is not directionally applied:
· residual monomer;
· water sorption; and
· water solubility.
Therefore, only one test run or build cycle for each test is needed using any available device
configuration within the confines of the validated manufacturing process considerations of build
volume placement (e.g., part orientation, build plate location, and other parametric
considerations) and leftover material reuse parameters, as described in Section II.
Biocompatibility Evaluation
To identify the biocompatibility endpoints to include as part of your biocompatibility evaluation
you should use Attachment A of the FDA guidance Use of International Standard ISO 10993-1,
Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk
management process,8 referred to in the rest of this document as the FDA Biocompatibility
Guidance for brevity. FDA considers the devices covered by this guidance to be categorized as
Surface Devices in contact with mucosal membrane with a permanent contact duration of >30
days and you should assess the endpoints below per Attachment A of the FDA Biocompatibility
Guidance.
· Cytotoxicity
· Sensitization
8 Available at https://www.fda.gov/regulatory-information/search-fda-guidance-documents/use-international-
standard-iso-10993-1-biological-evaluation-medical-devices-part-1-evaluation-and

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· Irritation or Intracutaneous Reactivity
Rationale in Lieu of Testing: If the subject device is manufactured from the identical raw
materials using identical manufacturing processes as a predicate device with the same type and
duration of tissue contact, and any changes in geometry are not expected to impact the biological
response, this is typically sufficient to establish substantially equivalent biocompatibility, if
documentation such as that outlined in Attachment F of the FDA Biocompatibility Guidance is
also provided.
Testing: If you determined that testing is needed to address some or all of the identified
endpoints, FDA recommends that complete test reports be provided for all tests performed unless
a declaration of conformity without supplemental information can be appropriately provided, as
discussed in Attachment E of the FDA Biocompatibility Guidance. Any test-specific positive,
negative, and/or reagent controls should perform as expected, and protocol deviations should be
thoroughly described and justified; however, note that certain protocol deviations may invalidate
comparison to the performance criteria listed below, resulting in the need for submission of a
Traditional, Special, or Abbreviated 510(k).
8. Test name: Biocompatibility endpoints (identified from FDA Biocompatibility
Guidance)
Methodology: FDA currently-recognized versions of biocompatibility consensus
standards
· ISO 10993-1 Biological evaluation of medical devices – Part 1: Evaluation and
testing within a risk management process
· ISO 7405 Dentistry – Evaluation of biocompatibility of medical devices used in
dentistry (this standard is an application of ISO 10993-1 to dental devices)
Performance Criteria: All direct contacting components of the device and device-
specific instruments should be determined to have an acceptable biological response.
Performance Criteria Source: The FDA Biocompatibility Guidance
Additional Considerations: For any biocompatibility test samples with an adverse
biological response, the biocompatibility evaluation should explain why the level of
toxicity seen is acceptable. Some comparison testing against a legally marketed predicate
may be necessary (and is considered acceptable under the Safety and Performance Based
Pathway) to support such a rationale as explained in the FDA Biocompatibility Guidance.
For standard biocompatibility test methods that include comparison device control
samples, the legally marketed comparison device control samples should perform as
expected.
Submission Information: Refer to FDA Biocompatibility Guidance