Overview - What ISO/TR 20896-2:2023 covers
ISO/TR 20896-2:2023 (Dentistry - Digital impression devices - Part 2) specifies methods for acquiring and analysing data to assess the accuracy of numerical models that describe the geometry of the mucosa and implant bodies in a patient’s jaw. It focuses on intra‑oral digital impression workflows for implanted devices and complements related standards for tooth preparations and model digitization. The technical report reviews theory, measurement techniques and test methods using scan bodies and other auxiliary devices to characterise device performance when scanning single and multiple implants.
Key technical topics and requirements
- Scope and definitions: Terms and definitions aligned with ISO 1942, ISO 16443 and ISO 18739 for dental CAD/CAM and implant vocabulary.
- Accuracy framework: Clear distinction and assessment methods for trueness, precision and external reliability (per ISO 5725 principles).
- Sources of uncertainty: Identification of clinical, device and environmental contributors to measurement uncertainty.
- Test objects: Guidance for designing and using single‑implant and multiple‑implant test objects that represent mucosal and implant geometries.
- Reference measurement: Use of calibrated reference measures and independent scanning devices to establish ground truth.
- Auxiliary methods and devices: Role of scan bodies, calliper measurements and extra‑oral photogrammetry in validating digital impressions.
- Assessment methods: Procedures for measuring position/orientation (measures of interest), repeated scanning for precision, design analysis and expression of accuracy results.
- Reporting requirements: Recommended content for test reports including device description, test object, method, results and raw test data.
- Informative annexes: Practical examples (scan body design, single/multiple implant test objects) and guidance on evaluating precision and external reliability.
Practical applications - who uses this standard
ISO/TR 20896-2:2023 is intended for:
- Manufacturers of intra‑oral scanners and digital impression devices validating implant‑related workflows.
- Dental CAD/CAM system developers and dental laboratory engineers assessing fit and prosthetic accuracy.
- Research laboratories and academic groups studying scan performance and new scanning technologies.
- Regulatory bodies and test laboratories developing conformity assessment protocols for device claims.
- Clinicians and prosthodontists seeking an evidence‑based understanding of scanner capabilities for implant prosthetics.
Use cases include device validation, comparative performance testing, product development, and informing clinical protocols for implant scanning.
Related standards (select)
- ISO 20896-1 - Methods for assessing accuracy (dentition).
- ISO 12836 - Digitizing physical impressions/models (fixed devices).
- ISO 5725-1 - Trueness and precision of measurement methods.
- ISO/IEC Guide 98-3 (GUM) - Expression of measurement uncertainty.
Keywords: ISO/TR 20896-2:2023, digital impression devices, implant accuracy, dental CAD/CAM, scan bodies, trueness, precision, intra‑oral scanner, mucosa geometry.
Open preview (PDF)Dentistry — Digital impression devices — Part 2: Methods for assessing accuracy for implanted devices