Overview
ISO/TR 18130:2016 - Dentistry - Screw loosening test using cyclic torsional loading for implant body/implant abutment connection of endosseous dental implants - is a Technical Report that provides a standardized bench protocol to evaluate screw loosening at the metallic implant body / implant abutment joint under cyclic torsional loading. The standard is intended for prefabricated metallic implant bodies, abutments and connecting parts (two‑part or multi‑part systems). It is explicitly not intended for temporary abutments, and it does not claim to predict in vivo clinical performance.
Key Topics and Requirements
- Test purpose: Determine extent of screw loosening (change in screw removal torque) after cyclic torsional loading.
- Specimen preparation: Use finished components or equivalents; assemble with manufacturer‑specified screw and tightening torque; components should be new and, if applicable, sterilized per manufacturer’s instructions.
- Initial measurement: Measure initial screw removal torque 5 minutes after assembly on at least six specimens to obtain mean and standard deviation.
- Cyclic torsional loading: Apply alternating clockwise and counterclockwise cyclic torque up to 10% of the screw tightening torque, at a rotation speed of 10° per minute, for up to 100,000 cycles. Record survival (cycles endured) or deformation/fracture.
- Instrumentation accuracy: Torque meter for initial removal torque with accuracy ≤ 0.3 N·cm; torque transducer in cyclic tester with accuracy within ±1% of maximum tested torque.
- Evaluation metrics: Compute ratios - mean initial removal torque to tightening torque, and mean post‑cycle removal torque to mean initial removal torque. Perform microscopic observation for wear/deformation.
- Minimum sample size: At least six specimens per test condition.
- Environmental/test condition: Conduct testing at (25 ± 10) °C.
- Test report content: Must include detailed specimen identification, test conditions, equipment, screw torques, cycle count, results (torque values and ratios), microscopic findings and any sterilization evidence.
Applications and Who Uses It
ISO/TR 18130 is used for:
- Dental implant manufacturers for product development, comparative evaluation of connection designs, materials testing and quality control.
- R&D and test laboratories performing bench tests for implant joint endurance and screw loosening behavior.
- Regulatory and conformity documentation where standardized preclinical mechanical test data are required.
- Design engineers assessing anti‑rotation features and screw joint reliability.
Note: This Technical Report supports bench evaluation and comparative assessment but is not a substitute for clinical data.
Related Standards
- ISO 1942, Dentistry – Vocabulary
- ISO 16443, Dentistry – Vocabulary for dental implant systems
- Bibliography references include ISO 898‑7, ISO/TS 13498 and ASTM F543‑07, which cover related torsion and screw testing methods.
Keywords: ISO/TR 18130:2016, screw loosening test, cyclic torsional loading, endosseous dental implants, implant abutment, implant body, screw removal torque, torsional cyclic torque.