oSIST prEN ISO 13356:2026

• Abstract:

  This document specifies the requirements and corresponding test methods for a biocompatible and bio-inert ceramic bone-substitute material based on yttriastabilized tetragonal zirconia (yttria tetragonal zirconia polycrystal, Y-TZP) for use as a material for surgical implants.

• Status: Not Published
• Public Enquiry End Date: 30-Oct-2026
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: VAZ - Healthcare
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 04-Sep-2026
• Due Date: 22-Jan-2027
• Ref Project: prEN ISO 13356 - Implants for surgery - Alumina ceramic material: Zirconia - Yttria-stabilized tetragonal zirconia (Y-TZP) (ISO/DIS 13356:2026)

• Revises: SIST EN ISO 13356:2015 - Implants for surgery - Ceramic materials based on yttria-stabilized tetragonal zirconia (Y-TZP) (ISO 13356:2015)
• Effective Date: 13-May-2026

Overview

oSIST prEN ISO 13356:2026 focuses on the requirements and corresponding test methods for biocompatible and bio-inert ceramic bone-substitute material based on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Developed by the Slovenian Institute for Standardization (SIST) and aligned with ISO/DIS 13356:2026, this standard ensures the quality and safety of zirconia-based ceramics used in surgical implants. The document outlines physical, chemical, and mechanical property requirements, offering guidance essential for manufacturers and stakeholders in the medical device and implant industry.

Key Topics

• Material Requirements: Specifies the chemical composition and microstructural characteristics of Y-TZP ceramics, including limits on impurities and oxides such as yttria (Y₂O₃), hafnia (HfO₂), and alumina (Al₂O₃).
• Physical and Mechanical Properties: Details test methods for measuring bulk density, flexural strength, Young’s modulus, hardness, and cyclic fatigue, ensuring that materials are suitable for surgical use.
• Testing and Quality Control: Divides required tests into two categories:
  • Category 1: Production control with tests for density, composition, microstructure, strength (including Weibull modulus), and monoclinic fraction after accelerated aging.
  • Category 2: Broader material specification, including all Category 1 tests plus hardness, Young’s modulus, fatigue strength, radioactivity, and detailed aging analysis.
• Test Methods: Provides references to internationally recognized test methods, such as ISO, EN, and ASTM, supporting reliable validation of material properties.

Applications

The primary application of oSIST prEN ISO 13356:2026 is in the development and production of ceramic materials for surgical implants. Key uses include:

• Orthopedic Implants: Y-TZP ceramics are widely used for hip, knee, and dental implants due to their superior biocompatibility, high mechanical strength, and wear resistance.
• Prosthetics and Orthotics: The standard supports safe and reliable use of ceramic materials in prosthetic and orthotic applications by ensuring consistency in material properties.
• Regulatory Compliance: Manufacturers can demonstrate conformity with international requirements, aiding market access and product approval.
• Quality Assurance: Regular and rigorous testing improves traceability and supports continued confidence in the long-term performance and safety of ceramic implant materials.

Related Standards

The document makes reference to several important standards for ceramic materials used in biomedical applications, including:

• ISO 3611: Geometrical product specifications - Micrometers for external measurements
• ISO 7500-1: Calibration and verification of static uniaxial testing machines
• ISO 14704 & ISO 14705: Test methods for flexural strength and hardness of monolithic ceramics
• ISO 17561 & EN 843-2: Test methods for measuring elastic moduli and related properties
• EN ISO 13383-1: Microstructural characterization of fine ceramics
• ISO 22214: Method for cyclic bending fatigue of ceramics
• EN ISO 18754: Determination of density and apparent porosity for ceramics
• EN ISO 20501: Weibull statistics for strength data
• ASTM C1499, ASTM C1161, ASTM C1327: Various methods for mechanical testing of advanced ceramics

Practical Value

Implementing oSIST prEN ISO 13356:2026 enables medical device manufacturers to:

• Enhance patient safety: By ensuring only high-quality, inert, and durable ceramics enter the surgical implant market
• Achieve regulatory acceptance: With clear reference to globally recognized test methods and property thresholds
• Optimize production processes: Through standardized material controls and detailed reporting requirements
• Facilitate innovation: By providing a reliable technical baseline for research and new product development in biomedical ceramics

This standard is an essential resource for quality management, research, and regulatory compliance in the field of ceramic-based surgical implants.

SLOVENSKI STANDARD
01-oktober-2026
Vsadki (implantati) za kirurgijo - Aluminijev keramični material: Cirkonij -
Tetragonalni cirkonij, stabiliziran z itrijem (Y-TZP) (ISO/DIS 13356:2026)
Implants for surgery - Alumina ceramic material: Zirconia - Yttria-stabilized tetragonal
zirconia (Y-TZP) (ISO/DIS 13356:2026)
Chirurgische Implantate - Keramische Werkstoffe: Zirconia - Yttrium-stabilisiertes
tetragonales Zirkoniumoxid (Y‑TZP) (ISO/DIS 13356:2026)
Implants chirurgicaux - Produits céramiques à base de zircone tétragonal stabilisée à
l'yttrium (Y-TZP) (ISO/DIS 13356:2026)
Ta slovenski standard je istoveten z: prEN ISO 13356
ICS:
11.040.40 Implantanti za kirurgijo, Implants for surgery,
protetiko in ortetiko prosthetics and orthotics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 13356
ISO/TC 150/SC 1
Implants for surgery — Alumina
Secretariat: DIN
ceramic material: Zirconia — Yttria-
Voting begins on:
stabilized tetragonal zirconia
2026-08-26
(Y-TZP)
Voting terminates on:
ICS: 11.040.40
2026-11-18
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 13356:2026(en)
DRAFT
ISO/DIS 13356:2026(en)
International
Standard
ISO/DIS 13356
ISO/TC 150/SC 1
Implants for surgery — Alumina
Secretariat: DIN
ceramic material: Zirconia — Yttria-
Voting begins on:
stabilized tetragonal zirconia
(Y-TZP)
Voting terminates on:
ICS:
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 13356:2026(en)
ii
ISO/DIS 13356:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Test categories . 2
4.1 General .2
4.1.1 Category 1 .2
4.1.2 Category 2 .2
4.2 Physical and chemical properties .2
5 Preparation of Test specimens . 4
6 Test Methods . 4
6.1 Bulk density .4
6.2 Chemical composition .4
6.3 Microstructure .4
6.3.1 Principle .4
6.3.2 Test report .5
6.3.3 Amount of monoclinic phase .5
6.5 Biaxial flexural strength.6
6.5.1 Principle .6
6.5.2 Apparatus .6
6.5.3 Preparation of test specimens .6
6.5.4 Procedure .7
6.5.5 Calculation of results .8
6.5.6 Test report .8
6.6 Four-point bending strength.8
6.7 Weibull modulus .9
6.8 Young’s modulus.9
6.9 Hardness .9
6.10 Cyclic fatigue .9
6.10.1 Principle .9
6.10.2 Apparatus .9
6.10.3 Sample size and preparation of test specimens .9
6.10.4 Procedure and sample requirement .9
6.10.5 Test Report.10
6.11 Radioactivity .10
6.12 Accelerated aging test .10
6.12.1 General .10
6.12.2 Procedure .10
6.12.3 Evaluation of accelerated aging outcome .10
Annex A (informative) Testing for radioactivity .11
Bibliography .13

iii
ISO/DIS 13356:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee SC 1,
Materials.
This forth edition cancels and replaces the third edition (ISO 13356:2015), which has been technically
revised.
— title changed to Implants for surgery —Alumina ceramic material:Zirconia — Yttria-stabilized tetragonal
zirconia (Y-TZP);
— normative references were updated;
— requirements and normative references in Table 1 were revised;
— the numbers of test specimens for each test item were reviewed;
— the equation for calculating the amount of monoclinic phase was corrected ;
— Testing for radioacitity was moved to an informative annex.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO/DIS 13356:2026(en)
Introduction
While no known surgical implant material has ever been shown to cause absolutely no adverse reactions
in the human body, long-term clinical experience with the material referred to in this document has shown
that an acceptable level of biological response can be expected when the material is used in appropriate
applications. However, this standard covers the raw material and not finished medical devices, where the
design and fabrication of the device can impact biological response.

v
DRAFT International Standard ISO/DIS 13356:2026(en)
Implants for surgery — Alumina ceramic material: Zirconia —
Yttria-stabilized tetragonal zirconia (Y-TZP)
1 Scope
This document specifies the requirements and corresponding test methods for bio-inert ceramic bone-
substitute material based on yttria-stabilized tetragonal zirconia (yttria tetragonal zirconia polycrystal,
Y-TZP) for use as a material for surgical implants.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment — Design and
metrological characteristics of micrometers for external measurements
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 14704, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural strength
of monolithic ceramics at room temperature
ISO 17561, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for elastic moduli of
monolithic ceramics at room temperature by sonic resonance
ISO 22214, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for cyclic bending
fatigue of monolithic ceramics at room temperature
EN 843-2, Advanced technical ceramics - Mechanical properties of monolithic ceramics at room temperature -
Part 2: Determination of Young's modulus, shear modulus and Poisson's ratio
EN ISO 13383-1, Fine ceramics (advanced ceramics, advanced technical ceramics) - Microstructural
characterization - Part 1: Determination of grain size and size distribution (ISO 13383-1:2012)
EN ISO 14705, Fine ceramics (advanced ceramics, advanced technical ceramics) - Test method for hardness of
monolithic ceramics at room temperature (ISO 14705:2016)
EN ISO 18754, Fine ceramics (advanced ceramics, advanced technical ceramics) - Determination of density and
apparent porosity (ISO 18754:2020)
EN ISO 20501, Fine ceramics (advanced ceramics, advanced technical ceramics) - Weibull statistics for strength
data (ISO 20501:2019)
ASTM C 1259, Standard Test Method For Dynamic Young's Modulus, Shear Modulus, And Poisson's Ratio For
Advanced Ceramics By Impulse Excitation Of Vibration
ASTM C 1327, Standard Test Method For Vickers Indentation Hardness Of Advanced Ceramics
ASTM C 1499-19, Standard Test Method For Monotonic Equibiaxial Flexural Strength Of Advanced Ceramics At
Ambient Temperature
ASTM C1198, Standard Test Method For Dynamic Young’S Modulus, Shear Modulus, And
Poisson’S Ratio For Advanced Ceramics By Sonic Resonance

ISO/DIS 13356:2026(en)
ASTM C1239-26, Standard Practice For Reporting Uniaxial Strength Data And Estimating Weibull Distribution
Parameters For Advanced Ceramics
ASTM C1331, Standard Practice For Measuring Ultrasonic Velocity In Advanced Ceramics With Broadband
Pulse-Echo Cross-Correlation Method
ASTM E112-13, Standard Test Methods For Determining Average Grain Size
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Test categories
4.1 General
The required tests are divided into two categories.
4.1.1 Category 1
The following test shall be performed for periodical production control:
a) bulk density;
b) chemical composition;
c) microstructure;
d) strength (including Weibull modulus);
e) accelerated aging (monoclinic fraction).
4.1.2 Category 2
The manufacturer shall define the general materials specification. In addition to all tests in 4.1.1, the
following tests shall be performed to demonstrate compliance with the material specification:
a) hardness;
b) Young’s modulus;
c) fatigue strength;
d) accelerated aging (strength);
e) quantity of monoclinic phase;
f) radioactivity.
4.2 Physical and chemical properties
The physical and chemical properties, when tested as specified in Clause 6, shall comply with the values
specified in Table 1.
ISO/DIS 13356:2026(en)
Table 1 — Limits for material properties
Test
Property Unit Requirement Reference Subclause
category
Bulk density g/cm 1 ≥ 6,00 ISO 18754 6.2
Chemical composition 6.3
ZrO +HfO +Y O ≥ 99,0
2 2 2 3
Y O > 4,5 to ≤ 6,0
2 3
% mass
HfO 1 ≤ 5
fraction
Al O ≤ 0,5
2 3
Other oxides ≤ 0,5
Microstructure 6.5
Grain size Intercept distance ≤ 0,4
ISO 13383-1
μm 1
ASTM E112
Standard deviation < 0,2
Amount of monoclinic See 6.5.3
% molar
phase
2 ≤ 20
fraction
Strength: alternative of 1) or 2)
a
1a) Biaxial flexure 1 ≥ 500 ASTM C1499 6.6
1b) Weibull modulus ISO 20501
1 ≥ 8 6.8
ASTM C1239
2a) 4-point bending ISO 14704
MPa
1 ≥ 800 EN 843–1 6.7
ASTM C1161
2b) Weibull modulus ISO 20501
1 ≥ 8 6.8
ASTM C 1239
Young's modulus ISO 17561
EN 843–2
GPa 2 ≥ 200 6.9
ASTM C1198
ASTM C1259
ASTM C1331
Hardness ISO 14705
GPa 2 ≥ 11,8 6.10
ASTM C1327
Cyclic fatigue limit stress
MPa 2 ≥ 320 ISO 22214 6.11
at 106 cycles
a
Radioactivity
Bq/kg 2 ≤ 200 — 6.12
Annex A
Accelerated aging 6.12
a
The radioactivity, defined as the sum of the mass activity of U238, Ra226, Th232, and determined by gamma spectroscopy
on the ready-to-use powder should be equal or less than 200 Bq/kg. This value will be reviewed at the next revision of this
Internation
...