Overview
EN ISO 6873:2013 - Dentistry: Gypsum products (ISO 6873:2013) is the CEN-adopted international standard that classifies and sets requirements for gypsum materials used in dental applications (impressions, moulds, casts, dies, model bases and model mounting). It specifies required properties, detailed test methods to verify compliance, and minimum labelling, packaging and user-instruction information for manufacturers and users.
Key topics and technical requirements
- Classification: Five material types defined for dental use:
- Type 1 - dental plaster for impressions
- Type 2 - dental plaster (mounting Class 1; models Class 2)
- Type 3 - dental stone for models
- Type 4 - high-strength, low-expansion dental stone (dies, model bases, CAD/CAM dies)
- Type 5 - high-strength, high-expansion dental stone (shrinkage compensation)
- Physical and performance requirements (selected):
- Fluidity (Type 1): ≥ 70 mm at 1.25 min (clause 5.2 / 7.2)
- Setting time: Type 1 range 2.5–5.0 min; all types must be within ±20% of the manufacturer’s claimed value (clause 5.3 / 7.3)
- Linear setting expansion: Specified limits per type (e.g., Type 4: 0.00–0.15% at 2 h and 0.00–0.18% at 24 h) (clause 5.4 / 7.4)
- Compressive strength: Minimums by type (e.g., Type 3 ≥ 20 MPa; Type 4 & 5 ≥ 35 MPa at 1 h) (clause 5.6 / 7.6)
- Reproduction of detail: Defined grooves to be reproduced depending on type (clause 5.7 / 7.7)
- Fracture behavior (Type 1): Must break cleanly and be reassemblable (clause 5.5 / 7.5)
- Testing conditions and sampling: Tests performed at (23 ± 2) °C and (50 ± 10) % RH; samples must be from a single lot and not past expiry (clauses 6.1–6.3).
- Labelling & instructions: Mandatory packaging, marking and user instructions to support safe and correct use (clause 8).
Applications and practical value
- Ensures consistent material performance for dental impressions, model fabrication, die preparation and CAD/CAM workflows.
- Supports quality control in dental material manufacturing and incoming inspection in dental laboratories.
- Provides objective, repeatable test methods for R&D, regulatory compliance and supplier qualification.
- Helps clinicians and lab technicians select the correct gypsum type based on strength and dimensional stability requirements.
Who uses this standard
- Dental material manufacturers and R&D teams
- Dental laboratories and prosthodontic technicians
- Quality assurance and regulatory affairs professionals
- Test laboratories and certification bodies
- Procurement specialists selecting materials for CAD/CAM and restorative workflows
Related standards
Keywords: EN ISO 6873:2013, gypsum products, dental plaster, dental stone, setting expansion, compressive strength, dental standard, gypsum testing, CAD/CAM dies.
