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.
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:
- 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
Original guidance
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