SIST EN ISO 23325:2020

SLOVENSKI STANDARD
01-september-2020
Zobozdravstvo - Odpornost zobnega amalgama proti koroziji (ISO 23325:2020)
Dentistry - Corrosion resistance of dental amalgam (ISO 23325:2020)
Zahnheilkunde - Korrosionsbeständigkeit von Dentalamalgam (ISO 23325:2020)
Médecine bucco-dentaire - Résistance à la corrosion des amalgames dentaire (ISO
23325:2020)
Ta slovenski standard je istoveten z: EN ISO 23325:2020
ICS:
11.060.10 Zobotehnični materiali Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 23325
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2020
EUROPÄISCHE NORM
ICS 11.060.10
English Version
Dentistry - Corrosion resistance of dental amalgam (ISO
23325:2020)
Médecine bucco-dentaire - Résistance à la corrosion Zahnheilkunde - Korrosionsbeständigkeit von
des amalgames dentaires (ISO 23325:2020) Dentalamalgam (ISO 23325:2020)
This European Standard was approved by CEN on 9 June 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23325:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 23325:2020) has been prepared by Technical Committee ISO/TC 106
"Dentistry" in collaboration with Technical Committee CEN/TC 55 “Dentistry” the secretariat of which
is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2021, and conflicting national standards shall
be withdrawn at the latest by January 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 23325:2020 has been approved by CEN as EN ISO 23325:2020 without any modification.

INTERNATIONAL ISO
STANDARD 23325
First edition
2020-06
Dentistry — Corrosion resistance of
dental amalgam
Médecine bucco-dentaire — Résistance à la corrosion des amalgames
dentaires
Reference number
ISO 23325:2020(E)
©
ISO 2020
ISO 23325:2020(E)
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 23325:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling . 3
5 Requirement . 3
6 Preparation of the dental amalgam test-piece . 4
6.1 General . 4
6.1.1 Temperature . 4
6.1.2 Mixing . 4
6.2 Apparatus for the preparation of the dental amalgam test-piece . 4
6.3 Materials and tolerances for construction of the mould . 4
6.4 Packing the mould, removal of test-piece and inspection for surface defects . 5
7 Test solution (artificial saliva) . 6
7.1 Reagents. 6
7.2 Stock solutions . 7
7.2.1 Stock Solution A . 7
7.2.2 Stock Solution B . 7
7.2.3 Stock Solution C . 7
7.3 Test solution . 7
8 Procedure for test-piece conditioning . 8
8.1 Apparatus . 8
8.2 Control test-pieces . 8
8.3 Corrosion test-pieces . 9
8.4 Replacement test-pieces . 9
9 Mechanical testing . 9
9.1 Apparatus for mechanical testing . 9
9.2 Procedure .10
9.2.1 Loading arrangement .10
9.2.2 Force application and fracture .11
9.3 Treatment of data .11
10 Test report .12
Bibliography .13
ISO 23325:2020(E)
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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 1, Filling
and restorative 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).
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 2020 – All rights reserved

ISO 23325:2020(E)
Introduction
This document sets a requirement, being the acceptable limit, for the reduction in strength of dental
amalgam that is a consequence of crevice corrosion when the test is conducted using the procedure
specified in this document. It uses one of the three corrosion test procedures present in ISO/TS 17988
for which a requirement is given in this document. The testing protocol is designed to accelerate the
effect, such that results are obtained in a time suited to an in vitro test. Its purpose is to differentiate
acceptable products from those that are not (by using a benchmark value) and not to rank products. It
is not intended for use in product comparison claims.
Specific qualitative and quantitative requirements for freedom from biological hazard are not
included in this document, but it is recommended that reference be made to ISO 10993-1 and ISO 7405
for assessing possible biological hazards. The test procedure in this document is inappropriate for
assessing possible biological hazards.
INTERNATIONAL STANDARD ISO 23325:2020(E)
Dentistry — Corrosion resistance of dental amalgam
1 Scope
This document specifies the requirements for the permissible reduction in strength resulting from
crevice corrosion of dental amalgam products that are within the scope of ISO 24234 or ISO 20749. It
provides details of the test procedure for determining this.
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, Water for analytical laboratory use — Specification and test methods
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions
and surface texture parameters
ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test
ISO 7488, Dentistry — Mixing machines for dental amalgam
ISO 13897, Dentistry — Dental amalgam reusable mixing-capsules
ISO 24234, Dentistry — Dental amalgam
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
dental amalgam alloy
alloy in fine particles, composed mainly of silver, tin and copper, which when mixed with dental mercury
(3.2), produces a dental amalgam for dental restoration
[SOURCE: ISO 20749:2017, 3.1]
3.2
dental mercury
mercury supplied for use in the preparation of dental amalgam
[SOURCE: ISO 20749:2017, 3.2]
ISO 23325:2020(E)
3.3
pre-capsulated product
product supplied in a sealed capsule that contains measured amounts of dental amalgam alloy (3.1)
powder and dental mercury (3.2) with masses that are appropriate for the production of a mass of dental
amalgam that is considered to be suitable for a single small or medium size restoration in a single tooth
Note 1 to entry: The dental amalgam alloy powder and dental mercury are separated by a barrier that is broken
immediately prior to mixing, allowing their contact. The capsule remains sealed until mixing has been completed.
[SOURCE: ISO 20749:2017, 3.3]
3.4
dental amalgam alloy tablet
quantity of dental amalgam alloy (3.1) powder that has been compressed to form a single entity for the
purpose of providing a pre-dosed quantity of the alloy that, when mixed with an appropriate mass of
dental mercury (3.2), produces a mass of dental amalgam that is considered to be suitable for a single
small or medium size restoration in a single tooth
Note 1 to entry: During mixing, the tablet is intended to break apart, forming a fine powder.
[SOURCE: ISO/TS 20746:2016, 3.4]
3.5
dental mercury sachet
measured quantity of dental mercury (3.2) supplied in a sachet (for use in a reusable mixing capsule)
in a mass that, when mixed with an appropriate mass of dental amalgam alloy (3.1), produces a mass
of dental amalgam that is considered to be suitable for a single small or medium size restoration in a
single tooth
Note 1 to entry: The sachet is intended to rupture during mixing to allow the dental mercury to come into contact
with the dental amalgam alloy powder.
Note 2 to entry: A dental mercury sachets may be referred to as a dental mercury pillow.
[SOURCE: ISO/TS 20746:2016, 3.5]
3.6
hertzian-loading strength-reduction corrosion test
test in which a test-piece is immersed for a defined period of time in a specified solution (at a specified
temperature) in a way that creates crevice corrosion conditions on one surface, after which it is removed
from the solution and fractured with the force to do this then compared with the force to fracture an
identical test-piece subjected to ageing in air at the same temperature
Note 1 to entry: Fracture is initiated from the surface subjected to crevice corrosion conditions and proceeds by
radial crack growth.
[SOURCE: ISO/TS 17988: 2014, 3.8]
3.7
radial cracking
fracture pattern of a Hertzian-loaded test-piece in which (more or less) planar cracks form along radii,
normal to the face of the disc shaped test-piece, thus dissecting it into two or more sectors
Note 1 to entry: Such radial cracks initiate on the test surface of the test-piece and propagate through the disc to
produce approximately equiangular dissection in most cases.
2 © ISO 2020 – All rights reserved

ISO 23325:2020(E)
EXAMPLE Some radial fracture patterns in disc shaped test-pieces are illustrated here:
[SOURCE: ISO/TS 20746:2016, 3.8]
3.8
top surface
surface of the disc shaped test-piece that has been produced by carving back unset amalgam that is
above the level of the mould until the surface of the test-piece is flat and level with that mould surface
[SOURCE: ISO/TS 20746:2016, 3.6]
3.9
test surface
surface of the disc shaped test-piece that has been produced by contact with the polished glass plate
when the mixed amalgam is packed into the mould
[SOURCE: ISO/TS 20746:2016, 3.7]
3.10
mixing machine for dental amalgam
DEPRECATED: amalgamator
electrically-powered mixing machine that operates using an oscillating action for mixing dental
amalgam alloy (3.1) and dental mercury (in a capsule) to produce a dental amalgam
[SOURCE: ISO/TS 17988: 2014, 3.12]
4 Sampling
Products shall be procured in packages that have been produced for retail.
For pre-capsulated dental amalgam products, procure a sufficient number of capsules from a single lot.
For dental amalgam alloy in the form of a powder supplied in bulk or in tablets, procure sufficient dental
amalgam alloy and a sufficient number of dental mercury sachets from single lots. The dental mercury
sachets shall conform to ISO 24234.
NOTE In this context, “sufficient” is deemed to be the quantity to make the required number of test-pieces
and the maximum number of test-pieces allowed to replace any that are rejected.
At least 3,0 g of dental amal
...