oSIST prEN ISO 23401-1:2026

SLOVENSKI STANDARD
01-marec-2026
Zobozdravstvo - Obložni materiali za proteze - 1. del: Trde vrste materialov
(ISO/DIS 23401-1:2026)
Dentistry - Denture lining materials - Part 1: Hard type materials (ISO/DIS 23401-1:2026)
Zahnheilkunde - Unterfütterungswerkstoffe - Teil 1: Harte Werkstoffe (ISO/DIS 23401-
1:2026)
Médecine bucco-dentaire - Produits pour intrados de prothèse dentaire - Partie 1:
Produits durs (ISO/DIS 23401-1:2026)
Ta slovenski standard je istoveten z: prEN ISO 23401-1
ICS:
11.060.10 Zobotehnični materiali Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 23401-1
ISO/TC 106/SC 2
Dentistry — Denture lining
Secretariat: ANSI
materials —
Voting begins on:
Part 1: 2026-01-22
Hard type materials
Voting terminates on:
2026-04-16
ICS: 11.060.10
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 is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 23401-1:2026(en)
DRAFT
ISO/DIS 23401-1:2026(en)
International
Standard
ISO/DIS 23401-1
ISO/TC 106/SC 2
Dentistry — Denture lining
Secretariat: ANSI
materials —
Voting begins on:
Part 1:
Hard type materials
Voting terminates on:
ICS: 11.060.10
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 is circulated as received from the committee 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
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Published in Switzerland Reference number
ISO/DIS 23401-1:2026(en)
ii
ISO/DIS 23401-1:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
4.1 Types .2
4.2 Classes .2
5 Requirements . 2
5.1 Appearance .2
5.1.1 Liquid .2
5.1.2 Powder, paste and sheet .2
5.2 Consistency .3
5.3 Peak temperature .3
5.4 Porosity and defects .3
5.5 Surface finish .3
5.6 Water sorption .3
5.7 Water solubility . .3
5.8 Knoop hardness .3
6 Sampling . 3
7 Test methods . 3
7.1 Conditions for testing .3
7.2 Preparation of test specimens .4
7.3 Visual inspection .4
7.3.1 Appearance .4
7.3.2 Porosity and defects .4
7.3.3 Surface finish .4
7.4 Consistency .4
7.4.1 Apparatus .4
7.4.2 Procedure .5
7.5 Peak temperature .5
7.5.1 Apparatus .5
7.5.2 Procedure .5
7.6 Water sorption and solubility .6
7.6.1 Materials .6
7.6.2 Apparatus .7
7.6.3 Preparation of test specimens .8
7.6.4 Procedure .8
7.6.5 Calculation and expression of results.9
7.7 Knoop hardness .9
7.7.1 Apparatus and materials .9
7.7.2 Preparation of test specimens .10
7.7.3 Procedure .10
8 Requirement for packaging, marking and instructions supplied by the manufacturer .10
8.1 Packaging .10
8.2 Marking and manufacturer’s instructions for use .10
Bibliography .12

iii
ISO/DIS 23401-1:2026(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 106, Dentistry, Subcommittee SC 2,
Prosthodontic materials, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 55, Dentistry, in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 23401-1:2023), which has been technically
revised.
The main changes are as follows:
— A part of title changes “Chairside denture base relining materials” to “Denture lining materials”
A list of all parts in the ISO 23401 series can be found on the ISO website.
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 23401-1:2026(en)
Introduction
ISO 23401 consists of the following parts, under the general title Dentistry – Denture lining materials.
— ISO 23401-1
— ISO 23401-2: former ISO 10139-1
— ISO 23401-3: former ISO 10139-2
The purpose of denture lining materials is to improve the fit of dentures to the oral mucosa. These materials
allow same-day lining of dentures. Thus, they can be a useful material for the general denture patients and
especially for bedridden patients who may have no access to dental surgery.
Denture lining materials are classified as either hard-type or soft-type depending on the hardness of the
material. The hard type materials are mainly used when the denture in use no longer fits the morphology of
the oral mucosa, while the soft type materials are used for patients who are particularly susceptible to feel
pain in the oral mucosa, and there are two types of materials: short-term materials and long-term materials,
depending on the period of use in the mouth.
Requirements and test methods for the soft type materials are defined in detail by ISO 23401-2 and
ISO 23401-3, but it is extremely difficult to incorporate the hard type materials in these International
Standards of soft lining materials because of the differences in the main components, curing mechanisms
and physical properties.
Also, chairside denture base relining materials and denture base materials covered by ISO 20795-1 and
ISO 20795-2 differ in polymerization method and required properties. As chairside denture base relining
materials are partially or even mainly handled intraorally, properties such as consistency and exothermicity
during intra-oral polymerization are quite important.
Therefore, ISO 23401-1:2023 was developed and published, which specifies requirements and test methods
for chairside denture lining materials for hard type.
Subsequent discussions on the need to develop standards for chairside denture lining materials for soft type
resulted in a confirmation and agreement that no new standards would be developed, as these are covered
by ISO 10139-1:2018 and ISO 10139-2:2016. Based on this resolution, it was decided to review the title of
the standard. Additionally, the possibility of integrating standards for denture lining materials including
ISO 10139-1:2018 and ISO 10139-2:2016 will be considered.
Specific qualitative and quantitative requirements for freedom from biological hazard are not included
in this document, but it is recommended that, in assessing possible biological or toxicological hazards,
reference be made to ISO 10993-1 and ISO 7405.

v
DRAFT International Standard ISO/DIS 23401-1:2026(en)
Dentistry — Denture lining materials —
Part 1:
Hard type materials
1 Scope
This document specifies the requirements for acrylic hard type materials used as chairside denture
lining materials and the test methods to determine compliance with these requirements. This document
also specifies requirements for packaging and marking the products and for the instructions for use to be
supplied by the manufacturer.
The use of hard type denture lining materials specified by this document is limited to acrylic dentures.
This document is not applicable to soft type denture lining materials.
NOTE 1 Acrylic hard type materials contain acrylic and methacrylic monomers such as acrylic acid esters and
substituted (meth)acrylic acid esters and their polymers.
NOTE 2 Acrylic dentures are made of polymers such as poly (acrylic acid esters), poly (substituted acrylic acid
esters) and rubber-modified poly (methacrylic acid esters).
NOTE 3 This material can be used for laboratory applications as well as chairside procedures.
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 1942, Dentistry — Vocabulary
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 4545-1, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 6344-3, Coated abrasives — Determination and designation of grain size distribution — Part 3: Microgrit
sizes P240 to P5000
ISO 8601-1, Date and time — Representations for information interchange — Part 1: Basic rules
ISO 20795-1, Dentistry — Base polymers — Part 1: Denture base polymers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942, ISO 20795-1 and the
following apply.
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/

ISO/DIS 23401-1:2026(en)
3.1
denture lining material
denture base lining material
dental material designed to be used on the intaglio surface of a denture base to modify its adaptation to
soft tissues
[SOURCE: ISO 19
...