Overview
ISO 17254:2016 - Dentistry - Coiled springs for use in orthodontics specifies how to characterize, test, package and label coiled springs used in orthodontic appliances. The standard defines required product information that manufacturers must declare, the test methods to compare physical and mechanical properties, sampling rules, and packaging/labelling requirements intended to help clinicians and purchasers make informed comparisons between spring products.
Key topics and requirements
- Scope: Applies to coiled springs for orthodontic appliances and gives methods to compare their physical and mechanical behaviour.
- Declared properties: Manufacturers must declare dimensions, mechanical properties and chemical composition; test results shall be within the manufacturer’s declared ranges when tested per the standard.
- Dimensions:
- Manufacturers state inner diameter (id), outer diameter (od), unloaded length (lu) and total length (lt) to the nearest 0.01 mm.
- Measurement equipment accuracy: 0.005 mm (calipers, micrometers, optical comparators, etc.).
- Mechanical properties:
- Elastic behaviour during unloading: maximum extension (εmax), maximum compression (cmax).
- Spring loads on unloading after loading to the specified maximum at 80%, 60%, 40% and 20% of maximum extension/compression (L80%max, L60%max, L40%max, L20%max).
- Test apparatus: calibrated mechanical testing machine; crosshead rate 0.5–10.0 mm/min.
- Test temperature: 23 ± 2 °C, except temperature-sensitive springs tested at 36 ± 1 °C.
- Specimen length for testing: (20 ± 0.2) mm or the unloaded length if less than 20 mm.
- Sampling: Six specimens from a single batch for each test; each specimen measured for all declared dimensions and properties.
- Hazardous elements: Cadmium, beryllium and nickel are designated hazardous; manufacturers must state mass fractions when present > 0.1%.
- Packaging & labelling:
- Required information: manufacturer name/address, product/trade name, spring design, lot number, quantity, intended use and warnings for hazardous elements.
- Packaging must protect against contamination in transit and storage.
Applications and users
- Who uses it: orthodontic spring manufacturers and suppliers, test laboratories, quality managers, dental device regulators, dental laboratories, and clinicians who compare springs for clinical selection.
- Practical uses:
- Product specification and quality control for manufacturing and incoming inspection.
- Comparative evaluation of springs’ mechanical behaviour for clinical selection.
- Regulatory and procurement documentation (labelling, hazardous element disclosure).
- Test-lab protocols for standardized mechanical testing.
Related standards
- ISO 1942 - Dentistry vocabulary (terms and definitions referenced).
- ISO 10993-1 and ISO 7405 - referenced for biological/biocompatibility evaluation (recommended for assessing toxicological hazards).