ISO 23317-2025 PDF

Full title and description

ISO 23317:2025 — Implants for surgery — Materials — Simulated body fluid (SBF) preparation procedure and test method to detect apatite formation in SBF for initial screening of bone-contacting implant materials. This International Standard specifies a standardized SBF formulation and an in vitro screening test to evaluate apatite formation on the surfaces of bulky, bone-contacting implant materials as an initial screening tool for bioactivity assessment.

Abstract

This document specifies a procedure for preparing simulated body fluid (SBF) and a test method intended as an initial in vitro screening tool to detect apatite formation on implant material surfaces. The standard notes that SBF test results alone do not establish bone-bonding ability and that the method is limited to bulky solid materials (porous, particulate or dissolved materials are excluded).

General information

• Status: Published.
• Publication date: 2025-06-12 (Edition 4 published June 2025).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 11.040.40 (Implants for surgery).
• Edition / version: Edition 4 (2025).
• Number of pages: 15.

Scope

ISO 23317:2025 defines the preparation procedure for simulated body fluid (SBF) and an immersion/test method to detect and evaluate apatite formation on the surfaces of bulky solid materials used for bone-contacting implants. It is intended as an initial in vitro screening method and explicitly excludes porous materials, particulate materials and solute molecules or ions because of sample-volume and analysis limitations. The standard emphasizes that positive SBF results are indicative of apatite-forming ability but are not, by themselves, proof of in vivo bone-bonding; complementary in vitro and in vivo tests are recommended.

Key topics and requirements

• Standardized SBF composition and reagent-grade requirements to reproduce ionic conditions that simulate human plasma for apatite nucleation tests.
• Stepwise SBF preparation procedure, including solvent, salt additions, buffering and filtration/sterilization guidance to reduce variability between laboratories.
• Specimen preparation and handling requirements for bulky solid implant materials (surface cleaning, dimensions, pre-conditioning).
• Immersion/exposure conditions (temperature, static or dynamic exposure, solution volume-to-surface-area ratios and recommended exposure durations) that affect apatite nucleation kinetics.
• Endpoints and analytical techniques for detecting and characterizing apatite (typical approaches include surface imaging and compositional analysis such as SEM, XRD, FTIR, elemental mapping and surface chemistry measurements).
• Interpretation guidance and limitations: how to read the screening results, risks of false positives/negatives (method sensitivity to SBF formulation and test parameters) and the requirement to confirm promising results with additional in vitro or in vivo testing.

Typical use and users

Primary users include biomaterials scientists, R&D teams at orthopaedic and dental implant manufacturers, academic research laboratories studying implant surface bioactivity, and conformity/regulatory engineers preparing preclinical evidence for regulatory submissions. The test is commonly used early in material and surface-development workflows as a screening step to identify surfaces or treatments that promote apatite-like mineral deposition before more costly biological or animal studies.

Related standards

ISO 23317 sits within the broader set of standards and guidance relevant to implants and medical-device evaluation. Commonly referenced related standards include the ISO 10993 series for biological evaluation of medical devices (biocompatibility), ISO 13485 for medical device quality management systems, and material-specific standards for implant materials (for example the ISO 5832 series for metallic implant materials). Users should consider ISO 23317 results alongside biological evaluation and regulatory guidance (e.g., national regulator expectations) when building a safety and performance dossier.

Keywords

Simulated body fluid; SBF; apatite formation; in vitro screening; bone-contacting implant materials; bioactivity; implant surface testing; biomaterials; ISO/TC 150; apatite-forming ability.

FAQ

Q: What is this standard?

A: ISO 23317:2025 is an International Standard that specifies a standardized simulated body fluid (SBF) preparation procedure and an in vitro test method to screen for apatite formation on the surfaces of bulky, bone-contacting implant materials.

Q: What does it cover?

A: It covers SBF composition and preparation, specimen preparation for bulky solid materials, immersion/exposure conditions and recommended analytical approaches to detect and characterise apatite formation. It is intended as an initial screening tool and excludes porous, particulate or dissolved materials.

Q: Who typically uses it?

A: Biomaterials researchers, implant manufacturers (R&D and preclinical teams), testing laboratories and regulatory/submission specialists use ISO 23317 as part of early bioactivity screening for new materials and surface treatments.

Q: Is it current or superseded?

A: Current — ISO 23317:2025 (Edition 4) was published in June 2025 and replaces earlier editions (the 2014 edition was withdrawn). Users should reference the 2025 text for the up-to-date procedure and requirements.

Q: Is it part of a series?

A: Yes — it is part of ISO work on surgical implants and materials developed under ISO/TC 150 (surgical implants) and its subcommittees; users commonly apply it alongside other medical-device standards such as the ISO 10993 biocompatibility series and quality/management standards (ISO 13485) when assembling device evidence.

Q: What are the key keywords?

A: Simulated body fluid (SBF), apatite, in vitro screening, bioactivity, bone-contacting implants, implant materials, apatite-forming ability.