Technical Considerations for Dental Ceramics Used in Artificial Teeth and Restorations
This guidance covers dental ceramics regulated under 21 CFR 872.6660 (Porcelain powder) and 21 CFR 872.3920 (Porcelain tooth). It applies to devices consisting of kaolin, felspar, quartz mixtures used in producing artificial teeth, jacket crowns, facings, bridges, and veneers. The guidance specifically addresses Type I (powders, pastes, aerosols) and Type II (other forms) ceramics across five classes based on clinical use.
What You Need to Know? 👇
What is the FDA’s Safety and Performance Based Pathway for dental ceramics?
The Safety and Performance Based Pathway is an optional FDA framework allowing manufacturers to demonstrate substantial equivalence by meeting FDA-identified performance criteria rather than directly comparing their device to a predicate device, providing a less burdensome regulatory approach.
Which dental ceramic devices are covered under this FDA guidance?
This guidance covers Class II dental ceramics regulated under 21 CFR 872.6660 (porcelain powder) and 21 CFR 872.3920 (porcelain tooth), including materials for artificial teeth, crowns, bridges, and veneers. Dental implants and temporary materials are excluded.
What are the key performance tests required for dental ceramics under this pathway?
Six main tests are required: flexural strength, chemical solubility, fracture toughness, radioactivity, linear thermal expansion coefficient, and glass transition temperature. All tests follow FDA-recognized ISO 6872 standards with specific performance criteria based on ceramic classification.
How are dental ceramics classified for performance testing purposes?
Dental ceramics are classified into five classes (Class 1-5) based on ISO 6872 standards, ranging from single-unit anterior prostheses (Class 1) to prostheses involving four or more units (Class 5), with increasingly stringent performance requirements.
What biocompatibility testing is required for dental ceramics?
Required biocompatibility endpoints include cytotoxicity, sensitization, oral mucosa irritation, acute systemic toxicity, subacute/subchronic toxicity, and genotoxicity. Testing follows ISO 10993-1 and ISO 7405 standards for devices with prolonged tissue contact.
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 biocompatibility data may be sufficient with proper documentation per FDA Biocompatibility Guidance Attachment F requirements.
What You Need to Do 👇
Recommended Actions
- Determine the appropriate class (1-5) for your dental ceramic device based on intended use
- Conduct all required mechanical testing according to ISO 6872
- Prepare Declarations of Conformity for mechanical testing results
- Perform biocompatibility evaluation according to ISO 10993-1 and ISO 7405
- Consider using existing biocompatibility data if materials and manufacturing processes are identical to predicate device
- Prepare complete test reports for all biocompatibility testing performed
- Document any deviations from test protocols with proper justification
- Submit results summary for all tests in addition to other required documentation
Key Considerations
Non-clinical testing
- Flexural strength testing according to ISO 6872 with specific minimum values for each class (50-800 MPa)
- Chemical solubility testing with limits between <100 and <2000 µg/cm²
- Fracture toughness testing with minimum values for each class (0.7-5.0 MPa√m)
- Radioactivity testing with limit ≤ 1.0 Bq⋅g−1 of 238U
- Linear thermal expansion coefficient testing (deviation ≤ 0.5 × 10−6 K−1)
- Glass transition temperature testing (deviation ≤ 20°C)
Biocompatibility
- Required testing for external communicating devices with prolonged/permanent contact:
- Cytotoxicity
- Sensitization
- Oral Mucosa Irritation
- Acute Systemic Toxicity
- Subacute/Subchronic Toxicity
- Genotoxicity
Relevant Guidances 🔗
- Use of ISO 10993-1 for Biological Evaluation and Testing of Medical Devices
- Safety and Performance Based Pathway for 510k Substantial Equivalence Demonstration
Related references and norms 📂
- ISO 6872: Dentistry – Ceramic materials
- 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