Testing and Safety Requirements for Denture Base Resins
This guidance covers denture base resins (Class II devices, regulated under 21 CFR 872.3760) composed of materials such as methyl methacrylate, intended for fabrication of patient-specific denture bases for full or partial dentures. It includes five types of polymers/materials: heat-polymerizable, autopolymerizable, thermoplastic, light-activated, and microwave cured materials. The guidance excludes OTC relining/repairing resins, preformed denture teeth, and partially fabricated denture kits.
What You Need to Know? 👇
What is the Safety and Performance Based Pathway for denture base resins?
The Safety and Performance Based Pathway allows 510(k) submitters to demonstrate substantial equivalence using FDA-established performance criteria rather than direct comparison to a predicate device, streamlining the regulatory process for denture base resins.
Which types of denture base polymers are covered by this FDA guidance?
The guidance covers five types: Type 1 (heat-polymerizable), Type 2 (autopolymerizable), Type 3 (thermoplastic), Type 4 (light-activated), and Type 5 (microwave cured) materials, as defined in ISO 20795-1.
What are the key mechanical performance criteria for denture base resins?
Key criteria include ultimate flexural strength (≥60-65 MPa), flexural modulus (≥1500-2000 MPa), stress intensity factor (≥1.9 MPa•m1/2), fracture work (≥900 J/m2), and limits for residual monomer, water sorption, and solubility.
What additional considerations apply to 3D printed denture base resins?
3D printed resins require validation of the complete workflow system, build parameters, dimensional accuracy verification, anisotropy testing across different print orientations, and documentation of material reuse processes and manufacturing consistency.
What biocompatibility testing is required for denture base resins?
Devices must be evaluated for cytotoxicity, sensitization, and irritation/intracutaneous reactivity as surface devices with permanent mucosal membrane contact >30 days, following ISO 10993-1 and ISO 7405 standards.
Can manufacturers use existing biocompatibility data instead of new testing?
Yes, if the device uses identical raw materials and manufacturing processes as a predicate device with same tissue contact, existing data may establish substantial equivalence without new testing, provided proper documentation is submitted.
What You Need to Do 👇
Recommended Actions
- Determine if device falls within scope of guidance
- Conduct all required mechanical testing according to ISO 20795-1
- Perform biocompatibility evaluation per ISO 10993-1
- For 3D printed resins, validate manufacturing process and document additional requirements
- Prepare Declaration of Conformity (DoC) for mechanical tests
- Submit complete test reports for biocompatibility unless DoC is appropriate
- Document all manufacturing processes and controls
- Prepare appropriate labeling including user instructions
- Consider Pre-Submission if additional testing beyond guidance is needed
- Prepare 510(k) submission following Safety and Performance Based Pathway requirements
Key Considerations
Non-clinical testing
- Ultimate flexural strength testing according to ISO 20795-1
- Flexural modulus testing according to ISO 20795-1
- Stress intensity factor testing according to ISO 20795-1
- Fracture work testing according to ISO 20795-1
- Residual monomer testing according to ISO 20795-1
- Water sorption testing according to ISO 20795-1
- Water solubility testing according to ISO 20795-1
Labelling
- Instructions for end-user if fabricated at point-of-care
- Identification of compatible bonding agents
- Instructions for relining or repair if applicable
Biocompatibility
- Cytotoxicity testing
- Sensitization testing
- Irritation or Intracutaneous Reactivity testing
Safety
- Compliance with ISO 20795-1 performance criteria for mechanical properties
- Water sorption ≤ 32 μg/mm³
- Water solubility requirements based on polymer type
Other considerations
For additively manufactured (3D printed) denture resins:
- Identification of validated workflow and systems
- Printing parameters documentation
- Build volume placement specifications
- Leftover material reuse process validation
- Dimensional measurements verification
- Additional performance testing considering anisotropy
Relevant Guidances 🔗
- Safety and Performance Based Pathway for 510k Substantial Equivalence Demonstration
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Recommended Format and Content for Non-Clinical Bench Performance Testing in Medical Device Premarket Submissions
- Content and Decision-Making Process for 510k Submissions: Determining Substantial Equivalence
Related references and norms 📂
- ISO 20795-1: Dentistry – Base polymers – Part 1: Denture base polymers
- 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