ISO 10139-2:2016

Overview

ISO 10139-2:2016 - Dentistry: Soft lining materials for removable dentures (Part 2: Materials for long-term use) specifies performance and labeling requirements for soft denture lining materials intended for long-term use (greater than 30 days). The standard covers mechanical and physical properties, test methods, and requirements for packaging, marking and manufacturer’s instructions. These lining materials can also be used in maxillofacial prostheses.

Key topics and requirements

• Classification by softness
  • Type A (soft): 24 h Shore A hardness >25 and ≤50
  • Type B (extra soft): 24 h Shore A hardness ≤25
• Shore A hardness tests
  • Measurements at 24 hours and 30 days after conditioning; tests use ISO 7619‑1 durometer method and specimens are conditioned in water (37 ±1 °C).
  • Limits at 30 days: Type A ≤55, Type B ≤35 (5 s reading).
• Bond strength to denture base
  • Minimum bond strength when tested: ≥1.0 MPa for Type A and ≥0.5 MPa for Type B for at least 8 of 10 specimens.
• Water sorption and solubility
  • Water sorption: increase in mass per volume shall not exceed 20 µg/mm for at least 4 of 5 specimens.
  • Water solubility: loss in mass per volume shall not exceed 3 µg/mm for at least 4 of 5 specimens. If exceeded in ≥2 specimens, the manufacturer must disclose amount and nature of solubles.
• Testing and sampling
  • Specifies specimen preparation, storage, test conditions and statistical pass/fail criteria.
• Packaging, marking and instructions
  • Requirements for immediate container labeling and user instructions to ensure correct clinical application and safe handling.

Practical applications

• Ensures consistent quality and predictable clinical behavior of soft denture liners used for tissue cushioning, retention improvement, and patient comfort.
• Supports product development and quality control for dental-material manufacturers, including formulation, batch testing and labeling.
• Guides dental laboratories and prosthodontists in selecting materials appropriate for prostheses that require long-term resilience and adhesion.
• Aids regulatory bodies and testing laboratories in certifying conformity to international test methods and performance thresholds.

Who uses this standard

• Dental materials manufacturers and R&D teams
• Dental laboratory technicians and prosthodontists
• Clinical researchers evaluating soft liners
• Regulatory and conformity assessment bodies
• Test laboratories performing Shore A, bond, sorption and solubility tests

Related standards

• ISO 10139-1 (short-term use)
• ISO 7619-1 (Shore hardness test)
• ISO 20795-1 (denture base polymers)
• ISO 7405 and ISO 10993-1 (biocompatibility guidance)
• ISO 3696 (water for analytical use)

Keywords: ISO 10139-2:2016, soft denture lining, long-term use, Shore A hardness, bond strength, water sorption, water solubility, maxillofacial prostheses, dental materials.