EN ISO 10271:2020

SLOVENSKI STANDARD
01-november-2020
Nadomešča:
SIST EN ISO 10271:2011
Zobozdravstvo - Preskusne metode ugotavljanja korozije za kovinske materiale
(ISO 10271:2020)
Dentistry - Corrosion test methods for metallic materials (ISO 10271:2020)
Zahnheilkunde - Korrosionsprüfverfahren für metallische Werkstoffe (ISO 10271:2020)
Médecine bucco-dentaire - Méthodes d'essai de corrosion des matériaux métalliques
(ISO 10271:2020)
Ta slovenski standard je istoveten z: EN ISO 10271:2020
ICS:
11.060.10 Zobotehnični materiali Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 10271
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2020
EUROPÄISCHE NORM
ICS 11.060.10 Supersedes EN ISO 10271:2011
English Version
Dentistry - Corrosion test methods for metallic materials
(ISO 10271:2020)
Médecine bucco-dentaire - Méthodes d'essai de Zahnheilkunde - Korrosionsprüfverfahren für
corrosion des matériaux métalliques (ISO 10271:2020) metallische Werkstoffe (ISO 10271:2020)
This European Standard was approved by CEN on 28 August 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 10271:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 10271:2020) 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 March 2021, and conflicting national standards shall
be withdrawn at the latest by March 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.
This document supersedes EN ISO 10271:2011.
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 10271:2020 has been approved by CEN as EN ISO 10271:2020 without any modification.

INTERNATIONAL ISO
STANDARD 10271
Third edition
2020-08
Dentistry — Corrosion test methods
for metallic materials
Médecine bucco-dentaire — Méthodes d'essai de corrosion des
matériaux métalliques
Reference number
ISO 10271:2020(E)
©
ISO 2020
ISO 10271:2020(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.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 10271:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test methods . 3
4.1 Static immersion test . 3
4.1.1 Information required . 3
4.1.2 Application . 3
4.1.3 Reagents . 3
4.1.4 Apparatus . 3
4.1.5 Solution preparation . 4
4.1.6 Samples . 4
4.1.7 Test procedure . 5
4.1.8 Elemental analysis . 6
4.1.9 Test report . 6
4.2 Electrochemical test . 6
4.2.1 Information required . 6
4.2.2 Application . 6
4.2.3 Reagents . 6
4.2.4 Apparatus . 7
4.2.5 Solution preparation . 7
4.2.6 Samples . 7
4.2.7 Test procedure . 9
4.2.8 Test report .12
4.3 Sulfide tarnish test (cyclic immersion) .13
4.3.1 Information required .13
4.3.2 Application .13
4.3.3 Reagents .13
4.3.4 Apparatus .13
4.3.5 Solution preparation .14
4.3.6 Samples .14
4.3.7 Test procedure .14
4.3.8 Inspection .15
4.3.9 Test report .15
4.4 Sulfide tarnish test (static immersion) .15
4.4.1 Information required .15
4.4.2 Application .15
4.4.3 Reagents .15
4.4.4 Apparatus .15
4.4.5 Solution preparation .16
4.4.6 Samples .16
4.4.7 Test procedure .17
4.4.8 Inspection .17
4.4.9 Test report .17
4.5 Static immersion test with periodic analysis .18
4.5.1 Information required .18
4.5.2 Application .18
4.5.3 Reagents .18
4.5.4 Apparatus .18
4.5.5 Solution preparation .18
4.5.6 Samples .19
4.5.7 Test procedure .20
ISO 10271:2020(E)
4.5.8 Elemental analysis .21
4.5.9 Test report .21
4.6 Dental amalgam.22
4.7 Crevice corrosion .22
4.7.1 Principle .22
4.7.2 Application .22
4.7.3 Test medium .22
4.7.4 Materials .22
4.7.5 Apparatus .22
4.7.6 Specimen.23
4.7.7 Procedure .24
4.7.8 Inspection .24
4.7.9 Test report .24
Annex A (informative) Corrosion test method development .26
Bibliography .32
iv © ISO 2020 – All rights reserved

ISO 10271:2020(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 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 third edition cancels and replaces the second edition (ISO 10271:2011), which has been technically
revised. The main changes compared with the previous edition are as follows:
— in the Scope, the statement about this document not being applicable to “appliances for orthodontics”
and “dental amalgam” has been removed;
— in 4.1.6.3, a NOTE has been added to the static immersion test method acknowledging that “measuring
the total surface area of orthodontic appliances can be difficult” and, therefore, if required in the
appropriate standard, “it is acceptable for the ion release for each element of a set of orthodontic
brackets to be reported in terms of µg in seven days for a specified number of orthodontic brackets”;
— since sodium sulfide hydrate (approximately 35 % Na S) analytical grade is not available in every
country, text was added to the appropriate test methods indicating that sodium sulfidenonahydrate
(Na S·9H O), ≤ 98 % may be used;
2 2
— this document has been harmonized with ISO 22674:2016 by making changes in the preparation
sections of the various test methods that reflect changes that were made for the preparation of
metals supplied for metal-ceramic restorations in ISO 22674:2016;
— subclause 4.6 “Dental amalgam” has been added, which refers the user to ISO/TS 17988 when testing
the corrosion behaviour of dental amalgam;
— subclause 4.7 “Crevice corrosion” has been added, which provides a test method to evaluate the
susceptibility of a dental metallic material to crevice corrosion.
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.
ISO 10271:2020(E)
Introduction
1)
This document was developed from the original Technical Report (ISO/TR 10271 ) as a result of
worldwide demand for standard test methods to determine the acceptability of metallic materials for
oral restorations in relation to corrosion.
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 or toxicological hazards.
The testing of the corrosion behaviour of metallic materials in dentistry is complicated by the diversity
of the materials themselves, their applications and the environment to which they are exposed.
Variation occurs between devices and within the same device during the exposure time. The type of
corrosion behaviour or effect can also vary with exposure time. Accordingly, it is not possible to specify
a single test capable of covering all situations, nor is it a practical proposition to define a test for each
situation. This document, therefore, gives detailed procedures for test methods that have been found to
be of merit as evidenced by considerable use.
In the second edition, two new test methods were added. To supplement the existing static immersion
test, a static immersion test with periodic analysis was added. A major reason for the addition of this
test is that the rate of corrosion of most dental metallic materials varies over time. Thus, the aim of
this supplementary test is to provide information on this variation in the corrosion of a dental metallic
material. A classification scheme to interpret the rate of corrosion of a tested material with time (i.e.
steady, decreasing, increasing) was not included as part of the static immersion test with periodic
analysis. It is intended to monitor the use of the test through appropriate working groups of ISO/TC 106
to ascertain whether a classification scheme is needed in a future revision of this document. In this
third edition, a classification scheme is still not included.
To supplement the sulfide tarnish test (cyclic immersion), a sulfide tarnish test (static immersion) was
also added to the second edition of this document. This test has been used successfully for many years
to evaluate the corrosion of silver alloys.
In addition, the second edition added Annex A, which sets out a procedure for each element of the test
system such that a consistent approach can be taken for the development of further test methods.
Equally, it is recognized that any element can represent only the current recommendation, but changes
in the future are unlikely to change the framework.
The third edition differs from the second by the removal of the statement in the Scope about
the document not being applicable to “appliances for orthodontics” and “dental amalgam”. With
the appliances for orthodontics change in mind, a NOTE was added to the static immersion test
acknowledging that “measuring the total surface area of orthodontic appliances can be difficult” and
stating that, if required in the appropriate standard, “it is acceptable for the ion release for each element
of a set of orthodontic brackets to be reported in terms of µg in seven days for a specified number of
orthodontic brackets”. Also, with reference to dental amalgam, a subclause on dental amalgam (see 4.6)
has been added, which refers the user to ISO/TS 17988 when testing the corrosion behaviour of dental
amalgam. Additionally, there is a clarification statement that the test methods given in 4.1 to 4.5 are
still not applicable to the evaluation of dental amalgam.
The third edition was harmonized with ISO 22674:2016 by adding to the preparation sections of the
various test methods the following change concerning metals supplied for metal-ceramic restorations:
— “Following the manufacturer’s instructions, simulate the oxidation procedure and four ceramic
firings at the highest temperature recommended for fusing ceramic to the metallic material.
Remove and place the specimens on a ceramic plate (which is at room temperature) to cool to room
temperature after the oxidation and ceramic firing simulation.”
1) Withdrawn document.
vi © ISO 2020 – All rights reserved

ISO 10271:2020(E)
Additionally, since sodium sulfide hydrate (approximately 35 % Na S) analytical grade is not available
in every country, this third edition includes a statement, which was added to the appropriate test
methods, indicating that sodium sulfide nonahydrate (Na S·9H2O), ≤ 98 % may be used.
Also of importance, a test method to evaluate the susceptibility of a dental metallic material to crevice
corrosion was added as 4.7.
It is not the purpose of this document to propose corrosion test methods for specific applications or to
set limits as precise as those that may be required in a standard relating to a type of product and its
application.
INTERNATIONAL STANDARD ISO 10271:2020(E)
Dentistry — Corrosion test methods for metallic materials
1 Scope
This document specifies test methods and procedures to determine the corrosion behaviour of metallic
materials used in the oral cavity. It is intended that these test methods and procedures be referred to in
individual International Standards specifying such metallic materials.
This document is not applicable to dental instruments.
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 1042, Laboratory glassware — One-mark volumetric flasks
ISO 1942, Dentistry — Vocabulary
ISO 3585, Borosilicate glass 3.3 — Properties
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test
ISO 7183, Compressed-air dryers — Specifications and testing
ISO/TS 17988, Dentistry — Corrosion test methods for 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 https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
breakdown potential
E
p
least noble potential at which pitting or crevice corrosion (3.4), or both, initiates and propagates
3.2
corrosion
physicochemical interaction between a metallic material and its environment that results in a partial
or total destruction of the material or in a change of its properties
3.3
corrosion product
substance formed as a result of corrosion (3.2)
ISO 10271:2020(E)
3.4
crevice corrosion
corrosion (3.2) associated with and taking place in or near a narrow aperture or crevice
3.5
current density
value of electric current per unit surface area flowing through a conductor
3.6
dynamic immersion test
test in which the specimen (3.15) is exposed to a corrosive solution under conditions of relative motion
between specimen and solution
3.7
electrode potential
potential difference between the specimen (3.15) and a reference electrode
3.8
electrolyte
solution or liquid that conducts an electrical current by means of ions
3.9
open-circuit potential
E
ocp
potential of an electrode measured with respect to a reference electrode or another electrode when no
current flows
3.10
pitting corrosion
localized corrosion (3.2) that results in pits
3.11
potentiodynamic test
test in which the electrode potential (3.7) is varied at a predetermined rate and the relationship between
current density (3.5) and electrode potential is recorded
3.12
potentiostatic test
test in which the electrode potential (3.7) is maintained constant
3.13
sample
totality of material for one type being tested, the group of all such specimens (3.15)
3.14
set
subgroup of the specimens (3.15) of a sample (3.13)
3.15
specimen
test piece
individual single example of an object for testing
3.16
static immersion test
test in which the specimen (3.15) is exposed to a corrosive solution under conditions of effectively no
relative motion between specimen and solution
3.17
stress corrosion
corrosion (3.2) resulting from the combined action of static tensile stress and an electrolyte (3.8)
2 © ISO 2020 – All rights reserved

ISO 10271:2020(E)
3.18
synthetic saliva
test medium that approximates the relevant chemistry of natural saliva
3.19
tarnish
surface discoloration due to the chemical reaction between a metallic material and its environment
3.20
zero-current potential
E
z
potential at which cathodic and anodic currents are equal
4 Test methods
4.1 Static immersion test
4.1.1 Information required
Composition, including hazardous elements, in accordance with the appropriate International Standard,
shall be provided.
4.1.2 Application
This is an accelerated test that is intended to provide quantitative data on the metal ions released from
metallic materials under in vitro conditions relevant to those expected in the oral cavity.
4.1.3 Reagents
4.1.3.1 Lactic acid (2-hydroxypropanoic acid, C H O ), ≥ 85 %, analytical grade.
3 6 3
4.1.3.2 Sodium chloride (NaCl), analytical grade.
4.1.3.3 Water, in accordance with grade 2 of ISO 3696.
4.1.3.4 Ethanol or methanol (C H OH or CH OH), analytical grade.
2 5 3
4.1.3.5 Compressed air, oil- and water-free, in accordance with ISO 7183.
4.1.4 Apparatus
4.1.4.1 Containers, of borosilicate glass, in accordance with ISO 3585 and with dimensions of
approximately 16 mm inner diameter by 160 mm in height.
4.1.4.2 pH meter, calibrated, with a sensitivity of at least ±0,05 pH.
4.1.4.3 Chemical analysis instrumentation, capable of measuring ion concentration in µg/ml, e.g.
inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma optical
emission spectrometry (ICP-OES) or atomic absorption spectroscopy (AAS).
4.1.4.4 Micrometer screw gauge, accurate and reading to 0,01 mm.
4.1.4.5 Silicon carbide paper, in accordance with ISO 6344-1.
ISO 10271:2020(E)
4.1.4.6 Volumetric flasks, of borosilicate glass, 1 000 ml, class A, in accordance with ISO 1042.
4.1.5 Solution preparation
Prepare an aqueous solution comprising 0,1 mol/l lactic acid and 0,1 mol/l sodium chloride within a
few hours of use. For example, dissolve (10,0 ± 0,1) g ≥ 85 % C H O (4.1.3.1) and (5,850 ± 0,005) g NaCl
3 6 3
(4.1.3.2) in approximately 300 ml of water (4.1.3.3). Transfer into a 1 000 ml volumetric flask (4.1.4.6)
and fill to the mark. The pH shall be 2,3 ± 0,1. If it is not, the solution shall be discarded and the reagents
checked.
4.1.6 Samples
4.1.6.1 Fabrication
4.1.6.1.1 Cast
Specimens shall be cast in accordance with the manufacturer’s recommendations.
4.1.6.1.2 Prefabricated
Prefabricated parts or devices shall be used in the as-received condition.
4.1.6.1.3 Other
Specimens prepared by other methods, e.g. machined, sintered, eroded, shall be tested in the as-
manufactured condition after suitable cleaning.
4.1.6.2 Sampling
The number of specimens shall be sufficient to provide at least two parallel sets. The number of
specimens in a set may vary.
4.1.6.3 Sample surface area
The total surface area of the sample shall be at least 10 cm after preparation.
NOTE It is recognized that measuring the total surface area of orthodontic appliances can be difficult.
Therefore, for prefabricated appliances, such as orthodontic brackets, it is acceptable to report the corrosion
rate in terms of ion release per sample, where the sample consists of sets of items that represent the appliance
in clinical use. As an example, it is acceptable for the ion release for each element of a set of orthodontic brackets
to be reported in terms of µg in seven days for a specified number of orthodontic brackets, as required in the
appropriate orthodontic brackets’ standard.
4.1.6.4 Preparation
4.1.6.4.1 Cast samples
Remove any sprues, runners or other projections from the surface. Blast all surfaces with 110 µm to
250 µm pure alumina to remove investment.
For precious metals, it is recommended to blast all surfaces with 110 µm pure alumina. For non-precious
metals, it is recommended to blast with 250 µm pure alumina.
It is advised that the removal of sprues, runners and other projections is done cold (i.e. under running
water) to prevent transformations.
If recommended, heat-treat according to the manufacturer’s instructions.
4 © ISO 2020 – All rights reserved

ISO 10271:2020(E)
In the case of metals supplied for metal-ceramic restorations, test after the following simulated ceramic-
firing schedule has been applied.
— Following the manufacturer’s instructions, simulate the oxidation procedure and four ceramic
firings at the highest temperature recommended for fusing ceramic to the metallic material.
Remove and place the specimens on a ceramic plate (which is at room temperature) to cool to room
temperature after the oxidation and ceramic firing simulation.
— Remove at least 0,1 mm, as determined using a measuring instrument [e.g. micrometer screw gauge
(4.1.4.4)], from each surface using standard metallographic procedures, unless specimens are being
tested in the as-received condition. Use fresh abrasive paper for each metallic material. Finish with
P1200 wet silicon carbide paper (4.1.4.5). If the described procedure is not applicable, treat the
surfaces according to the manufacturer’s instructions for clinical use.
— Determine each sample surface area to the nearest 1 % (see NOTE in 4.1.6.3).
— Clean surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3).
Dry with oil- and water-free compressed air (4.1.3.5).
— If a specimen has any porosity visible on any surface intended to be exposed to the test solution, the
specimen shall be rejected and replaced with a new one.
4.1.6.4.2 Machined, sintered, eroded or electroformed samples
Heat-treat the specimens if this is recommended.
Remove at least 0,1 mm, as determined using a measuring instrument [e.g. micrometer screw gauge
(4.1.4.4)], from each surface using standard metallographic procedures unless specimens are being
tested in the as-received condition. Use fresh abrasive paper for each metallic material. Finish with
P1200 wet silicon carbide paper (4.1.4.5).
Determine each sample surface area to within ±0,1 cm (see NOTE in 4.1.6.3).
Clean surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3). Dry
with oil- and water-free compressed air (4.1.3.5).
4.1.6.4.3 Prefabricated parts/devices
Treat the surfaces according to the manufacturer’s instructions for clinical use.
Determine each sample surface area to within ±0,1 cm (see NOTE in 4.1.6.3).
Clean the surfaces ultrasonically for 2 min in ethanol or methanol (4.1.3.4). Rinse with water (4.1.3.3).
Dry with oil- and water-free compressed air (4.1.3.5).
4.1.7 Test procedure
Parallel specimen sets shall be treated in identical fashion. If a set consists of one specimen, it shall be
placed in a container (4.1.4.1) such that it does not touch the container surface except in a minimum
support line or point. If a set consists of two or more specimens, they may be placed in the same or a
number of separate containers, but if more than one is placed in a single container, they shall not touch.
Record the pH of the solution. Add the solution to each container sufficient to produce a ratio of 1 ml of
solution per 1 cm of sample surface area. The specimens shall be covered completely by the solution.
Record the volume of solution to an accuracy of 0,1 ml. Close the container to prevent evaporation of the
solution. Maintain at (37 ± 1) °C for 7 d ± 1 h. Remove the specimen(s) and record the pH of the solution.
Use an additional container (4.1.4.1) to hold a reference (“blank”) solution to be maintained in parallel
with the solutions containing the specimens. The reference solution shall be used to establish the
impurity concentration for each element of interest in the test solution. Add approximately the same
volume of solution as used for the solutions containing the specimens and record the volume to an
ISO 10271:2020(E)
accuracy of 0,1 ml. Close the container to prevent evaporation of the solution and maintain at (37 ± 1) °C
for the same time period as the solutions containing the specimens.
4.1.8 Elemental analysis
Use chemical analysis instrumentation (4.1.4.3) of adequate sensitivity. Analyse the solution
qualitatively and quantitatively. Emphasis shall be on those elements indicated in 4.1.1, but if impurities
are found to have a concentration greater than 0,1 % by mass in the original metal, they shall also
be reported. For each element of interest, subtract the value obtained for the element in the reference
solution from the value obtained in the test solution. The elements boron, carbon and nitrogen shall be
disregarded.
4.1.9 Test report
The test report shall contain the following information:
a) the method of analysis and detection limits of all the analysed elements;
b) any deviations from the preparation of specimens (see 4.1.6.4) or test procedure (see 4.1.7) and
their justification;
c) the number of specimens making up a set and the number of sets tested (see 4.1.6.2);
d) the calculated ion release for each element of each set (see 4.1.6.2) separately in µg/cm in seven
days from the elemental analysis of the corrosion solution (see 4.1.8) (see NOTE in 4.1.6.3), for
elements indicated in 4.1.1, as well as any others found; the sum of the ion release values for all the
elements of each set (i.e. the total metal ion release for the dental material); and the average total
ion release for the dental material in µg/cm in seven days (i.e. that sum divided by the number of
sets tested);
e) the presence of undissolved corrosion products, such as precipitates, and any discoloration of the
specimen surface;
f) the International Standard used (including its year of publication);
g) the method used (in this case, “static immersion test”);
h) the date of the test.
4.2 Electrochemical test
4.2.1 Information required
Composition, including hazardous elements, in accordance with the appropriate International Standard,
shall be provided.
4.2.2 Application
This test is intended to assess the corrosion susceptibility of metallic materials used in the oral cavity
using potentiodynamic polarization.
4.2.3 Reagents
4.2.3.1 Lactic acid (2-hydroxypropanoic acid, C H O ), ≥ 85 %, chemically pure.
3 6 3
4.2.3.2 Sodium chloride (NaCl), analytical grade.
4.2.3.3 Sodium hydroxide (NaOH), analytical grade.
6 © ISO 2020 – All rights reserved

ISO 10271:2020(E)
4.2.3.4 Water, in accordance with grade 2 of ISO 3696.
4.2.3.5 Argon or nitrogen gas, with a minimum purity of 99,99 %.
4.2.3.6 Ethanol or methanol (C H OH or CH OH), analytical grade.
2 5 3
4.2.3.7 Acetone [dimethyl ketone, (CH ) CO], analytical grade.
3 2
4.2.4 Apparatus
4.2.4.1 Test cell, temperature-controlled, of borosilicate glass, in accordance with ISO 3585.
NOTE A double-walled cell is unnecessary if the test is carried out at (23 ± 2) °C.
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4.2.4.2 Scanning potentiostat, potential range ±1 600 mV, current output range 10 A to 10 A.
4.2.4.3 Potential measuring instrument, with input impedance > 10 Ω and both the sensitivity and
accuracy to be able to detect a change of 1 mV over a potential change of ±1 600 mV.
4.2.4.4 Current-measuring instrument, capable of measuring a current to within ±1 % of the
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absolute value over a current range between 10 A and 10 A.
4.2.4.5 Working electrode (specimen holder).
4.2.4.6 Counter electrode(s), composed of high-purity vitreous carbon or platinum.
4.2.4.7 Reference electrode, either saturated calomel electrode (SCE) or Ag/AgCl electrode [saturated
silver chloride electrode (SSE)]. If a reference electrode other than a SCE is used, all reported potential
values shall be converted to millivolts (SCE) by reference to standard values with respect to the standard
hydrogen electrode. For example, E(SCE) = E(SSE) – 44 mV.
4.2.4.8 pH meter, calibrated, with a sensitivity of ±0,05 pH.
4.2.4.9 Silicon carbide paper, in accordance with ISO 6344-1.
4.2.4.10 Diamond paste,1 µm.
4.2.4.11 Micrometer screw gauge, accurate and reading to 0,01 mm.
4.2.4.12 Light microscope, minimum magnification of 50×.
4.2.5 Solution preparation
Dissolve 9,0 g NaCl (4.2.3.2) in approximately 950 ml water (4.2.3.4). Adjust to pH 7,4 ±0,1 using 1 %
C H O (4.2.3.1) or 4 % NaOH (4.2.3.3). Dilute with water to 1 000 ml.
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4.2.6 Samples
4.2.6.1 Fabrication
4.2.6.1.1 Cast
Specimens shall be cast in accordance with
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