SIST EN ISO 28399:2020

SLOVENSKI STANDARD
oSIST prEN ISO 28399:2019
01-september-2019
Zobozdravstvo - Proizvodi za zunanje beljenje zob (ISO/DIS 28399:2019)
Dentistry - Products for external tooth bleaching (ISO/DIS 28399:2019)
Zahnheilkunde - Externe Zahnbleichmittel (ISO/DIS 28399:2019)
Médecine bucco-dentaire - Produits d'éclaircissement dentaire, à usage externe
(ISO/DIS 28399:2019)
Ta slovenski standard je istoveten z: prEN ISO 28399
ICS:
11.060.01 Zobozdravstvo na splošno Dentistry in general
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
oSIST prEN ISO 28399:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 28399:2019

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oSIST prEN ISO 28399:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 28399
ISO/TC 106/SC 7 Secretariat: JISC
Voting begins on: Voting terminates on:
2019-06-14 2019-09-06
Dentistry — Products for external tooth bleaching
Médecine bucco-dentaire — Produits d'éclaircissement dentaire, à usage externe
ICS: 97.170
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 28399:2019(E)
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. ISO 2019

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COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
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
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Published in Switzerland
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oSIST prEN ISO 28399:2019
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
4.1 General . 2
4.2 Products for professional application . 2
4.3 Products for consumer application . 2
5 Requirements . 2
5.1 Concentration of active ingredients for bleaching . 2
5.2 Surface microhardness . 3
5.3 Surface erosion . 3
6 Test methods . 3
6.1 Preparation of tooth specimens . 3
6.2 Preparation and application of tooth bleaching product . 3
6.3 Surface microhardness . 3
7 Packaging, marking and information to be supplied by the manufacturer .3
7.1 General . 3
7.2 Packaging . 3
7.3 Marking and instructions for use . 4
Annex A (informative) Test method for the measurement of hydrogen peroxide concentration .5
Annex B (informative) Light microscopy method for measuring erosion of enamel and
dentine caused by products for external tooth bleaching . 6
Annex C (informative) Test method for laboratory assessment of tooth bleaching efficacy .18
Bibliography .21
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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 7, Oral
care products.
This second edition cancels and replaces the first edition (ISO 28399:2011), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— a light microscopy method is recommended as an example for the measurement of erosion of enamel
and dentine caused by products for external tooth bleaching.
— a visual assessment with shade guide has been revised.
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.
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Introduction
Products for external tooth bleaching are used in dentistry for changing the colour of natural teeth
towards a lighter or whiter shade. They are applied in the oral cavity directly on the outer surfaces
of teeth. This document includes requirements and test methods for products intended for external
bleaching of natural teeth by chemical means.
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oSIST prEN ISO 28399:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 28399:2019(E)
Dentistry — Products for external tooth bleaching
1 Scope
This document specifies requirements and test methods for external tooth bleaching products.
These products are intended for use in the oral cavity, either by professional application (in-office
tooth bleaching products) or consumer application (professional or non-professional home use of
tooth bleaching products), or both. It also specifies requirements for their packaging, labelling and
instructions for use. Maximum concentration of a bleaching agent for professional or non-professional
use is subject to each country’s regulatory body.
This document is not applicable to tooth bleaching products:
— specified in ISO 11609;
— those intended to change colour perception of natural teeth by mechanical methods (e.g. stain
removal) or using restorative approaches, such as veneers or crowns;
— auxiliary or supplementary materials (e.g. tray materials) and instruments or devices (e.g. lights)
that are used in conjunction with the bleaching products.
This document does not specify biological safety aspects of tooth bleaching products.
[2]
NOTE A tooth bleaching product can be evaluated for its biological safety using ISO 10993-1 and
[3]
ISO 7405 .
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 1942:2009, Dentistry — Vocabulary
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 8601, Data elements and interchange formats — Information interchange — Representation of dates
and times
ISO 11609:2017, Dentistry — Dentifrices — Requirements, test methods and marking
ISO 11664-1:2007, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664-2:2007, Colorimetry — Part 2: CIE standard illuminants
ISO/TR 28642:2016, Dentistry — Guidance on colour measurement
CIE s 014-6/E: 2013, Colorimetry — Part 6: CIEDE2000 Colour-Difference Formula
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
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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
bleaching
〈natural teeth〉 removal of intrinsic or acquired discolorations of natural teeth using chemicals,
sometimes in combination with the application of auxiliary means
[SOURCE: ISO 1942:2009, 2.28, modified]
3.2
professional home use
〈of a product〉 use prescribed by a professional and for use at home under the repeated supervision of
the dentist
3.3
erosion
〈of tooth surface〉 progressive loss of calcified tissue by chemical processes that do not involve
bacterial action
[SOURCE: ISO 1942:2009, 2.292, tooth erosion]
4 Classification
4.1 General
Products for external tooth bleaching can be classified for either:
a) professional application; or
b) consumer application.
NOTE Products for external tooth bleaching can be used alone or in conjunction with auxiliary means of
application.
4.2 Products for professional application
These products are tooth bleaching products that are intended by the manufacturer to be applied only
by dental professionals (in office tooth bleaching products).
4.3 Products for consumer application
These products are tooth bleaching products that are intended by the manufacturer to be applied by
the consumer (for professional home use or for non-professional home use).
NOTE Such external bleaching products can be prescribed by a dental professional or directly available to
consumers.
5 Requirements
5.1 Concentration of active ingredients for bleaching
The concentration of active ingredients for bleaching (equivalent to hydrogen peroxide) delivered by
the unexpired product according to manufacturer's instructions for use shall be within the range of
+10 % and -30 % of the original concentration stated by the manufacturer for the unopened product,
when tested in accordance with Annex A or other equivalent method.
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5.2 Surface microhardness
The reduction in the Knoop hardness (KHN) or Vickers hardness (VHN) enamel surface microhardness
before and after bleaching treatment shall not exceed 10 %, when tested in accordance with 6.3.
5.3 Surface erosion
Surface erosion of the teeth tested in accordance with B.6.1 shall be equal or less than the level which
is caused by the positive control (B.4.2), when tested in accordance with Annex B or other equivalent
methods.
6 Test methods
6.1 Preparation of tooth specimens
Prepare enamel and dentine specimens taken from a consistent location on extracted human or bovine
teeth, that have been stored in a neutralized solution that disinfects but does not alter the physical
properties. Grind the specimen surface under a constant flow of water in accordance with ISO 3696
starting at P400 and sequentially to a minimum of P1200 silicon carbide paper in accordance with
ISO 6344-1. Then polish the surface using a slurry or paste of 0,3 µm mean particle size aluminium
oxide. Ensure a minimum of 1 mm thickness of enamel or dentine tissue for the test specimen. Prevent
dehydration of test specimens during the preparation procedure.
6.2 Preparation and application of tooth bleaching product
The dispensing, processing and application of the tooth bleaching product used in tests shall follow
the manufacturer's instructions for use. The method of bleach application shall simulate the clinical
procedure in quantity, frequency and duration of the application. Between bleaching intervals, and for
24 h after the last bleach application prior to testing, specimens shall be stored at 37 °C in artificial
[8]
saliva solution similar to that described in the ANSI/ADA Specification No. 41 .
6.3 Surface microhardness
Evaluate enamel surface microhardness before and after bleaching treatment.
Determine KHN or VHN surface microhardness by applying a load of 0,49 N (equivalent to a 50 g load)
for 15 s. Evaluate a minimum of 10 specimens for each group, with three indentations for each specimen.
Prevent dehydration of test specimens during the specimen preparation procedure.
7 Packaging, marking and information to be supplied by the manufacturer
7.1 General
Additional information may be included at the discretion of the manufacturer or as required by
[4]
regulation .
7.2 Packaging
The components of the material shall be supplied in properly sealed containers which adequately
protect the contents and do not adversely affect the product quality.
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7.3 Marking and instructions for use
For each package, the following applies.
a) Information shall be clearly marked on the outermost package or containers appropriate to the
product, as indicated in Table 1.
b) Instructions shall accompany each package of the product and shall include the information
appropriate to the product, as indicated in Table 1.
Table 1 — Requirements for marking and instructions for use
Manufactur-
Outermost
No. Information Container er’s instruc-
package
tions for use
1 Name of the product M M M
2 Identification or name of the manufacturer M M M
3 Address of the manufacturer or the agent responsible for sale M — M
4 Recommended conditions of storage M — M
5 Manufacturer's lot or batch identification M M —
Expiry date in accordance with ISO 8601 for the materials
6 under the storage conditions recommended by the manu- M M —
facturer
7 Classification of the materials (Clause 4) M — M
8 Clinical application of the material (Clause 4) — — M
9 Number of containers M — —
10 Net mass of product in each container M M M
11 Chemical name of active ingredient(s) M — M
12 Concentration of active ingredient(s) M M M
13 Concentration equivalent to hydrogen peroxide M M M
14 Instructions for use — — M
Recommended auxiliary device(s), exposure times and any
15 special instructions for use of the equipment (for the mate- — — M
rials requiring an auxiliary device only)
Specific contra-indication(s) and/or warning(s), such as
16 — — M
“irritation”, “avoid contact with eyes”, as necessary.
Statement equivalent to “It is recommended that you consult
17 — — M
with your dental professional before using this product.”
18 Passes the surface erosion test. — — M
19 Date of latest revision, if applicable — — M
Explanation of symbols:
“M” indicates mandatory information.
“—” indicates non-mandatory information.

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Annex A
(informative)

Test method for the measurement of hydrogen peroxide
concentration
A.1 Principle
The content of hydrogen peroxide (H O ) in tooth bleaching products is determined using a modified
2 2
thiosulfate titration method.
A.2 Test condition
Perform the test at (23 ± 2) °C.
[12]
A.3 Procedure (modified thiosulfate titration method, USP )
Equivalent methods can also be used.
Use analytic grade sulfuric acid, potassium iodide, ammonium molybdate, sodium thiosulfate, starch
and hydrogen peroxide. Conduct a titration calibration curve using a series of freshly prepared H O
2 2
solutions at concentrations that include the highest possible H O concentration in the test product.
2 2
Add approximately 1,0 g (weighing precision to 0,001 g) of test product or an amount appropriate
to the test, with rapid stirring, to 400 ml distilled water that contains 10 ml of sulfuric acid (25 %),
25 ml potassium iodide (10 %), and 4 drops of ammonium molybdate solution (5 %). Use starch as the
indicator, and perform the titration using 0,1 N (normality) sodium thiosulfate.
Determine the H O content using the titration calibration curve.
2 2
When using standardized titrants (e.g. USP standard grade), construction of a calibration curve is not
necessary. Calculate the mass concentration of H O from the following equation:
2 2
C = (1,701 18× V/m) × Y/0,1 × 100
where
C is the mass concentration of H O , expressed as a percentage;
2 2
V is the titre of 0,1 N sodium thiosulfate, in millilitres;
M is the mass of the test product dispensed, in milligrams;
Y is the accurate concentration of sodium thiosulfate, in mol/litre.
Repeat the measurement five times (n = 5) and calculate the mean H O concentration.
2 2
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Annex B
(informative)

Light microscopy method for measuring erosion of enamel and
dentine caused by products for external tooth bleaching
B.1 Principle
The depth of erosion of enamel and dentine caused by products for external tooth bleaching is
determined using a light microscope.
Test Summary: Sound enamel and dentin slabs of approximately 4 × 4 × 1,4 millimetre (mm) are cut
from caries and erosion free molars or incisors of human or bovine tooth. These slabs are mounted on a
plastic rod and the natural surface of the slab is removed by sanding to expose fresh enamel or dentin.
The surface is protected with fingernail polish leaving a 1,0 mm unprotected stripe down the centre
of the fresh enamel or dentin surfaces. The specimens are exposed to the potentially erosive solution/
gel following manufacturer’s instructions or for standard solutions, 1 h while stirring. The specimens
are rinsed with distilled water (D-H O), cleansed in mild detergent solution, rinsed with ethanol, and
2
rinsed again with D-H O and visually inspected to assure that all product residues have been removed.
2
The specimens are then sliced perpendicular to the exposed stripe to yield 3 or 4 cross-section slices
from each specimen slab. The cross-section slices are mounted on a glass slide, and a digital image is
obtained under microscope. A digital image of a reference scale such as a TEM grid or mm ruler is also
obtained at the same magnification. The reference scale and the cross-section can be in the same digital
image. The digital image for each cross-section is evaluated for surface loss using software capable of
1)
assessing gray scale values of pixels . The surface loss for each cross-section from a specimen slab is
averaged to give the erosion loss for each specimen.
B.2 Test Condition
Perform the test at (23 ± 2) °C, i.e., ambient temperature.
B.3 Apparatus and materials
B.3.1 Apparatus
B.3.1.1 Dissecting Microscope with digital camera, see Figure B.1B.
B.3.1.2 Slow speed saw and diamond wafering blades, course or fine, see Figure B.1A.
B.3.1.3 Sandpaper, 600 carbide grit (1 200 grit EU standards).
B.3.1.4 Disposable beakers, 50 ml.
B.3.1.5 Glass beakers, 100 ml.
1) ImageJ software methods are described in B.10 as an example. ImageJ software is freely available and in the
public domain and downloadable from National Institute of Health, 9000 Rockville Pike, Bethesda, Maryland 20892,
USA, https: //imagej .nih .gov/ij/. ImageJ bundled with Java 1.8.0_112 (64-bit Java) is available for Windows system
and ImageJ bundled with Java 1.8.0_172 is available for Mac OS X and follow the installation instructions. This
information is given for the convenience of users of this document and does not constitute endorsement by ISO of
this software.
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[1]
B.3.1.6 Volumetric flask, 100 ml, in accordance with ISO 1042 , Class A
B.3.1.7 Magnetic stir plate and magnetic stir bars.
B.3.1.8 Plastic rods, 6 mm diameter × 15 cm length.
B.3.1.9 TEM grid, of known dimensions or mm scale to 0.5 mm.
B.3.1.10 pH/mV electrometer (pH meter), with a sensitivity of + 0,1 mV.
B.3.2 Materials
B.3.2.1 Citric acid monohydrate (C H O ·H O).
6 8 7 2
B.3.2.2 Sodium citrate dihydrate (Na C H O ·2H O).
3 6 5 7 2
B.3.2.3 Distilled water, in accordance with ISO 3696, Grade 2.
B.3.2.4 Potassium hydroxide (KOH) at 0,1 mol/l.
B.3.2.5 Hydrochloric acid (HCl) at 0,1 mol/l.
B.3.2.6 Ethanol, denatured.
B.3.2.7 Teeth (human or bovine) with caries free and erosion free surfaces, sufficient amount of
teeth for collecting six (4 × 4 × 1,4) mm specimens for each group, disinfected in storage solution.
B.3.2.8 Fingernail polish, pigmented.
B.3.2.9 Fingernail polish, clear.
B.3.2.10 Cyanoacrylate glue.
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B.3.2.11 Detergent solution, e.g. 1 % sodium lauryl sulfate solution.
Figure B.1 — Apparatus for preparing and measuring specimen. (A) Slow speed wafering saw
and, (B) Dissecting microscope with digital camera
B.4 Standard reference erosion controls
B.4.1 Negative control
Grade 2 distilled water (B.3.2.3) as the negative control.
B.4.2 Positive control
B.4.2.1 Prepare buffer solutions in a clean 100 ml glass beaker (B.3.1.5) or other suitable container.
B.4.2.2 Weigh powdered citric acid monohydrate (B.3.2.1) and sodium citrate dihydrate (B.3.2.2) in
separate weighing dishes; combine crystals in a 100 ml volumetric flask (B.3.1.6) and add distilled water
(B.3.2.3) until the meniscus nears the graduation line.
B.4.2.3 Determine the pH of these solutions using a suitably calibrated pH/mV electrometer (pH
meter) (B.3.1.10) and meter while agitating using a magnetic stirrer (B.3.1.7).
B.4.2.4 If the pH is more than ±0,05 units away from the expected pH then adjust the pH accordingly
with 0,1 mol/l potassium hydroxide (B.3.2.4) or 0,1 mol/l hydrochloric acid (B.3.2.5) to the expected value.
B.4.2.5 Add distilled water (B.3.2.3) to make up to the final volume of 100 ml.
Table B.1 — Positive controls
Sodium citrate Citric acid monohy- Expected
% Citric acid
dihydrate drate
mass fraction (Na C H O ·2H O) (C H O ·H O)
3 6 5 7 2 6 8 7 2
% Mass Mass pH
1,00 0,451 0,766 3,60
0,25 0,114 0,193 3,60
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B.5 Specimen preparation
B.5.1 General
Samples of enamel or dentin of 4 × 4 × 1,4 mm dimension are recommended for this procedure. Sound
enamel specimen may be obtained from caries and erosion free molars or incisors of human or bovine
tooth. Dentin specimens may be obtained from incisor or premolar roots (just below the dentino-
enamel junction). Sample preparation details are presented below organized by the specimen source.
B.5.2 Cutting an enamel slab from molar teeth (see Figure B.2)
B.5.2.1 Mount tooth (B.3.2.7) in a clamp such that the tooth is horizontal in the diamond saw (see
Figure B.2A)
B.5.2.2 Using water cooled diamond wafering blade remove the cusps of the tooth.
B.5.2.3 Set the saw micrometer to zero
B.5.2.4 Advance the holder toward the dentino-enamel junction 4,1 mm and cut the top of the tooth off
of the root (see Figure B.3E).
B.5.2.5 Retrieve the 4 mm section of tooth and mount in the clamp such that a smooth surface of caries
free enamel can be sliced off the tooth (see Figure B.2B).
B.5.2.6 Align the sample such that the outer edge of the tooth just touches the wafering blade, set the
micrometer to zero.
B.5.2.7 Advance the sample 1,4 mm.
B.5.2.8 Cut the enamel away from the tooth, preserving the removed enamel slice.
B.5.2.9 Carefully mount the enamel slice in the clamp (avoiding breaking the sample).
B.5.2.10 Align the sample to remove the tapered edge of the slice and remove the taper (see Figure B.2C).
Reset the micrometer to zero.
B.5.2.11 Advance the micrometer 4 mm and cut the enamel slab off of the slice.
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B.5.2.12 Retrieve the 4 × 4 × 1,4 mm slab and with a pencil place an ‘x’ mark on the inner cut side of
the slab.
Figure B.2 — Molar enamel slab preparation
B.5.3 Cutting an enamel slab from incisor teeth (see Figure B.3)
B.5.3.1 Mount the tooth in a clamp such that the tooth is perpendicular in the diamond
...