Overview
ISO 14356:2003 - "Dentistry - Duplicating material" defines requirements and test methods for dental duplicating materials used to form flexible moulds (negative impressions) from master models. These flexible moulds are primarily intended for producing positive refractory investment copies used in metal and ceramic prosthesis fabrication. The standard covers both reversible and non‑reversible duplicating materials, sampling, specimen preparation, testing conditions and required packaging, labelling and instructions for use.
Key topics and requirements
- Classification:
- Type 1 - Reversible duplicating materials (e.g., agar-based systems that can be re-melted and reused).
- Type 2 - Non‑reversible duplicating materials (one‑time gel/rubber set).
- Thermal limits (Type 1):
- Melting temperature shall not exceed the manufacturer’s stated maximum (tested per clause 8.1).
- Maximum pouring temperature specified by manufacturer shall not exceed 54 °C.
- Detail reproduction:
- Material must reproduce specified fine lines and features on the test block (clause 8.2).
- Compatibility:
- Must impart a smooth surface to - and separate cleanly from - refractory investments (and gypsum where applicable).
- Mechanical properties:
- Elastic recovery: ≥ 96.50% (tested per clause 8.4).
- Tear strength: ≥ 0.3 N/mm for Type 1 and ≥ 1.0 N/mm for Type 2 (clause 8.5).
- Biological resistance:
- Type 1 agar materials must show no fungal growth when tested (clause 8.6).
- Sampling and test conditions:
- Samples taken from a single manufacturing batch. Typical amounts: ~7.5 L for Type 1, 3.7 L for Type 2.
- Laboratory conditions: (23 ± 2) °C and (50 ± 10) % RH.
- Labelling, packaging and user instructions are specified to ensure safe and effective use.
Applications and users
ISO 14356 is essential for:
- Manufacturers of dental duplicating materials (product development, QC, compliance).
- Dental laboratories and prosthodontic technicians validating materials used for moulding and casting workflows.
- Regulatory bodies and procurement teams assessing conformity and performance claims.
- Standards committees and testing laboratories performing acceptance and routine performance tests.
Typical applications include producing refractory positive copies for metal and ceramic castings, creating gypsum copies, and any dental workflow that requires accurate, heat‑resistant moulding of master models.
Related standards
Relevant standards referenced include ISO 1942 (dental vocabulary), ISO 6873, ISO 7490, ISO 9694, ISO 11245, and ISO 11246 (standards addressing gypsum and refractory investment materials used with duplicating materials).