Overview
EN ISO 23325:2020 - Dentistry: Corrosion resistance of dental amalgam (ISO 23325:2020) specifies how to determine the allowable reduction in mechanical strength of dental amalgam caused by crevice corrosion. The standard defines a laboratory test procedure (an accelerated in vitro protocol) for dental amalgam products that fall within the scope of ISO 24234 or ISO 20749. Its primary aim is to set an acceptable limit for strength loss after corrosion so manufacturers and test laboratories can identify products that meet basic corrosion-resistance requirements.
Key topics and requirements
- Scope and objective: Defines permissible reduction in strength resulting from crevice corrosion and provides a test method to determine compliance. Not intended for ranking products or assessing biological hazards.
- Sampling and test-piece preparation: Requirements for sampling, mould construction, mixing and packing of amalgam to produce representative test specimens.
- Test solution (artificial saliva): Composition and preparation of reagents/stock solutions used to simulate oral conditions during testing.
- Conditioning and corrosion exposure: Controlled conditioning of control and corrosion test-pieces to accelerate crevice corrosion effects in vitro.
- Mechanical testing: Procedures and apparatus for mechanical strength measurement (loading arrangements, force application, fracture) and data treatment to quantify strength reduction.
- Test report: Required reporting elements to document test conditions and results.
- Normative references and definitions: Uses established terminology (e.g., pre‑capsulated product, alloy tablet, dental mercury sachet) and references related standards for equipment, terminology and test media.
Practical applications - who uses this standard
EN ISO 23325:2020 is useful for:
- Dental materials manufacturers - to validate corrosion resistance during product development and quality control of dental amalgam (pre‑capsulated products, tablets, sachets).
- Independent test laboratories - performing standardized corrosion and mechanical tests for certification or supplier claims.
- Regulatory and conformity bodies - assessing whether amalgam products meet accepted corrosion-resistance benchmarks for market approval.
- Procurement and quality assurance teams - specifying test requirements in supplier contracts and batch release protocols.
- Standards committees and researchers - referencing a harmonized test method when comparing materials or developing improved formulations.
Note: EN ISO 23325:2020 uses one of the corrosion procedures from ISO/TS 17988 and recommends separate guidance (e.g., ISO 10993-1, ISO 7405) for biological hazard assessment.
Related standards
Keywords: EN ISO 23325:2020, dental amalgam, corrosion resistance, crevice corrosion, artificial saliva, mechanical testing, ISO 24234, ISO 20749, dentistry standards.