ISO/PRF 21563

Dentistry -- Hydrocolloid impression materials

Médecine bucco-dentaire -- Produits pour empreintes à base d'hydrocolloïdes

General Information

• Status: Published
• ICS: 11.060.10 - Dental materials
• Technical Committee: ISO/TC 106/SC 2 - Prosthodontic materials
• Drafting Committee: ISO/TC 106/SC 2/WG 7 - Impression materials

RELATIONS

• Revised: ISO 21563:2013 - Dentistry -- Hydrocolloid impression materials
• Effective Date: 23-Apr-2020

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 21563
Second edition
Dentistry — Hydrocolloid impression
materials
Médecine bucco-dentaire — Produits pour empreintes à base
d'hydrocolloïdes
PROOF/ÉPREUVE
Reference number
ISO 21563:2021(E)
ISO 2021
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ISO 21563:2021(E)
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© ISO 2021

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Published in Switzerland
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ISO 21563:2021(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Classification of agar hydrocolloid impression materials ......................................................................................... 3

5 Requirements — Characteristics and properties ............................................................................................................... 4

6 Pre-test planning approaches ................................................................................................................................................................. 5

6.1 General ........................................................................................................................................................................................................... 5

6.2 Sampling ....................................................................................................................................................................................................... 5

6.3 Pre-test product examinations .................................................................................................................................................. 5

6.3.1 General...................................................................................................................................................................................... 5

6.3.2 Examinations for compliance with labelling requirements ....................................................... 5

6.3.3 Examinations for effectiveness of the packaging ................................................................................. 5

6.3.4 Examinations for compliance with requirements for instructions for use ................... 6

6.4 Essential pre-test preparatory practices .......................................................................................................................... 6

6.4.1 Laboratory conditions ................................................................................................................................................. 6

6.4.2 Apparatus function verification steps ........................................................................................................... 6

6.4.3 Test material handling and use ........................................................................................................................... 6

6.4.4 Simulated oral time/temperature treatment of specimens formed in

completely closed moulds........................................................................................................................................ 7

6.4.5 Order of conducting tests ......................................................................................................................................... 7

6.4.6 Test schedules timing .................................................................................................................................................. 7

6.4.7 Pass/fail determinations ........................................................................................................................................... 7

6.4.8 Expression of test results ......................................................................................................................................... 8

7 Test methods ............................................................................................................................................................................................................. 8

7.1 General ........................................................................................................................................................................................................... 8

7.2 Working time test (alginate materials only) .................................................................................................................. 8

7.2.1 Apparatus and materials (the array of devices or materials used or

available for an undertaking) .................. .............................................................................................................. 8

7.2.2 Specimen preparation ................................................................................................................................................. 8

7.2.3 Test procedure ................................................................................................................................................................... 9

7.2.4 Pass/fail determinations/and expression of results ........................................................................ 9

7.3 Initial setting time test (alginate impression materials only) ........................................................................ 9

7.3.1 Apparatus ............................................................................................................................................................................... 9

7.3.2 Specimen preparation ................................................................................................................................................. 9

7.3.3 Test procedure ................................................................................................................................................................... 9

7.3.4 Pass/fail determinations and expression of results .......................................................................10

7.4 Detail reproduction test before and after specimen disinfection ............................................................10

7.4.1 Apparatus and materials ........................................................................................................................................10

7.4.2 Examination and conditioning of equipment and accessories .............................................10

7.4.3 Specimen preparation ..............................................................................................................................................10

7.4.4 Test procedure steps .................................................................................................................................................12

7.4.5 Pass/fail determination and expression of results..........................................................................12

7.5 Compatibility with gypsum test ............................................................................................................................................12

7.5.1 Apparatus and materials ........................................................................................................................................12

7.5.2 Specimen preparation ..............................................................................................................................................13

7.5.3 Test procedure ................................................................................................................................................................14

7.5.4 Pass/fail determination and expression of results..........................................................................14

7.6 Elastic recovery test.........................................................................................................................................................................14

7.6.1 Apparatus and materials ........................................................................................................................................14

7.6.2 Specimen preparation ..............................................................................................................................................14

7.6.3 Test procedure ................................................................................................................................................................15

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ISO 21563:2021(E)

7.6.4 Calculation of results .................................................................................................................................................16

7.6.5 Pass/fail determinations and expression of results .......................................................................16

7.7 Strain-in-compression test ........................................................................................................................................................16

7.7.1 Apparatus and materials ........................................................................................................................................16

7.7.2 Specimen preparation ..............................................................................................................................................16

7.7.3 Test procedure ................................................................................................................................................................16

7.7.4 Calculation of results .................................................................................................................................................17

7.7.5 Pass/fail determinations and expression of results .......................................................................17

7.8 Tear strength test ...............................................................................................................................................................................17

7.8.1 Apparatus and materials ........................................................................................................................................17

7.8.2 Specimen preparation ..............................................................................................................................................18

7.8.3 Test procedure ................................................................................................................................................................19

7.8.4 Calculation of results .................................................................................................................................................19

7.8.5 Pass/fail determinations and expression of results .......................................................................19

7.9 Linear dimensional change test (Type 3A agar materials with companion alginate only) 20

7.9.1 Apparatus and materials ........................................................................................................................................20

7.9.2 Specimen preparation ..............................................................................................................................................20

7.9.3 Test procedure ................................................................................................................................................................21

7.9.4 Calculation of results .................................................................................................................................................21

7.9.5 Pass and fail determinations and expression of results ..............................................................21

7.10 Tensile bond strength test (Type 3A agar/companion alginate material specimen only) .21

7.10.1 Apparatus ............................................................................................................................................................................21

7.10.2 Specimen preparation ..............................................................................................................................................22

7.10.3 Specimen preparation steps ...............................................................................................................................22

7.10.4 Test procedure steps .................................................................................................................................................23

7.10.5 Calculation of results .................................................................................................................................................23

7.10.6 Pass/fail determination and expression of results..........................................................................23

8 Requirements — Labelling and instructions for use ...................................................................................................23

8.1 Labelling ....................................................................................................................................................................................................23

8.2 Requirements — Instructions for use ..............................................................................................................................24

8.2.1 General...................................................................................................................................................................................24

8.2.2 For all hydrocolloid impression materials covered by this document —

Agar and alginate ..........................................................................................................................................................24

8.2.3 Additional instructions for agar hydrocolloid impression materials only ..................25

8.2.4 Additional instructions for alginate hydrocolloid materials only ......................................25

Annex A (informative) Figures illustrating instruments and accessories used in tests...............................27

Annex B (informative) Tear test specimen preparation steps for an optional gripping method .......41

Bibliography .............................................................................................................................................................................................................................46

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ISO 21563:2021(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 second edition cancels and replaces the first edition (ISO 21563:2013), which has been technically

revised.
The main changes compared to the previous edition are as follows:

— The detail reproduction before and after disinfection for alginate powder and paste/paste materials

has been corrected to be 50 microns.

— The elastic recovery test has been modified to allow for the use of poly(methyl methacrylate) plates

as an alternative to glass or metal.
— Figures A.2, A.3, A.4, and A.6 have been corrected.
— Multiple editorial changes have been made throughout the document.

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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INTERNATIONAL STANDARD ISO 21563:2021(E)
Dentistry — Hydrocolloid impression materials
1 Scope

This document specifies the requirements and test methods for hydrocolloid impression materials. This

document helps to determine whether elastic aqueous agar and alginate hydrocolloid dental impression

materials, as prepared for retail marketing, are of the quality needed for their intended purposes. It also

specifies requirements for labelling and instructions for use. This document does not address possible

biological hazards associated with the materials. Assessment of these hazards is addressed in ISO 7405

and the ISO 10993 series.
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 6873, Dentistry — Gypsum products
ISO 3696, Water for analytical laboratory use — Specification and test methods
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 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 http:// www .electropedia .org/
3.1
bonding

adherence of the impression (3.6) material components in a single impression after each of the

interfacing materials has reached the level of effective setting required for successful removal from the

mouth
3.2
bulk container

labelled packaging holding a greater amount of otherwise unpackaged granular, liquid, powder, or other

loose substance than is usually needed for a single dental clinical or laboratory procedure

3.3
consumer packaging
retail packaging
sales packaging

packaging constituting, with its contents, a sales unit to the final user or consumer at the point of retail

[SOURCE: ISO 21067-1:2016, 2.2.7, modified — "retail packaging" and "sales packaging" have been

changed from preferred terms to admitted terms.]
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ISO 21563:2021(E)
3.4
elastic recovery
elastic properties required to recover adequately from deformation
3.5
extrusion

process of obtaining a liquefied Type 3 or Type 3A agar impression (3.6) material from the containing

cartridge or syringe
3.6
impression

negative copy of oral or craniofacial tissue surfaces obtained by placing a mouldable impression

material into contact with the tissue surfaces, and allowing it to harden, or to become elastic, such

that the entire impression material/tray assembly can be removed from the contact without significant

harm to the tissues or to the assembly

Note 1 to entry: A properly formed impression is capable of having a relatively fluid model (cast) forming material

poured against the intaglio surface so that, when the modelling material sets, a positive copy of the impressed

surfaces is formed.
3.7
initial setting time

time, measured from commencement of mixing components of a material, or otherwise activating the

chemistry involved, and ending at a time when results of a prescribed test show that the activated

material has begun to set at a rate indicating that the effective setting time will be reached at some

predictable time thereafter

Note 1 to entry: Initial setting times stated in the manufacturer’s instructions are useful to test operators, users

and standards developers because they can be helpful:

— in determining whether quality of a product has deteriorated before or after opening of the packaging; for

example, if the initial setting time found by the test operator or user corresponds closely to that stated in the

manufacturer’s instructions, it can be assumed that the product is of a quality suitable for testing or use;

— in the development of standards for certain materials when there is a need for a standard to identify a

reference point in time that can be used as a basis for specifying a later point in time at which a subsequently

specified procedure can safely begin.
3.8
liquefaction

process of heating an agar impression (3.6) or duplicating material to change it from the elastic gel state

to the mouldable or pourable sol state
3.9
non-reversible impression material

impression (3.6) material which, having been brought to the effective setting stage as required for

removal from the mouth, cannot be returned to the mouldable state required for forming impressions

3.10
primary packaging
primary container
DEPRECATED: immediate container
packaging designed to come into direct contact with the product

[SOURCE: ISO 21067-1:2016, 2.2.3, modified — The admitted term "primary container" and the

deprecated term "immediate container" have been added.]
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ISO 21563:2021(E)
3.11
reversible impression material

impression (3.6) material such as an agar hydrocolloid which, after having been brought to the gel state

for marketing purposes, can be heated so as to bring it to the relatively fluid colloid or paste-like state

required for making an impression

Note 1 to entry: Whereas in past years the “gel to sol” and “sol to gel” reversibility capacities of such impression

materials have allowed them to be recycled for repeated uses, modern infection control practices now discourage

user recycling of the reversible impression materials for repeated uses in the mouth.

3.12
secondary packaging
DEPRECATED: over packaging

packaging designed to contain one or more primary packagings (3.10) together with any protective

materials and accessory devices that may have to be provided for use with the product

[SOURCE: ISO 21067-1:2016, 2.2.4, modified — The deprecated term "over packaging" has been added;

"where required" has been replaced by "and accessory devices that may have to be provided for use

with the product".]
3.13
storing

process of holding increments of liquefied reversible agar hydrocolloid impression (3.6) material at a

reduced temperature pending time they will be injected or tempered for impression making purposes

3.14
strain-in-compression

flexibility/stiffness property ranges of materials so as to determine whether the set materials, when

formed as impressions (3.6), can be removed from the mouth without injury to impressed oral tissues

and will have adequate stiffness in the more flexible portions of impressions to resist deformation

when model-forming products are poured against them
3.15
tempering

process of holding a heavy or medium bodied agar impression (3.6) material in a slightly higher than

mouth temperature water bath, after the material has been placed into an impression tray, so as to

further reduce the sol state temperature as necessary for safe and effective seating in the mouth

3.16
unit packet

packaging containing only the amount of product usually needed for a single dental clinical or laboratory

application
4 Classification of agar hydrocolloid impression materials

The agar impression materials are classified according to the consistencies they exhibit while they are

ready for impressing against the oral or craniofacial tissue surfaces, and when tested according to 5.2.

— Type 1 heavy bodied, for making impressions of complete or partial dental arches, with or without

the use of companion increments of lighter bodied Type 2 or Type 3 agar impression materials.

— Type 2 medium bodied, for making impressions of complete and partial dental arches, with or

without the use of companion syringe-extruded increments of Type 3 agar materials.

— Type 3 light bodied, for syringe use with either the Type 1 or Type 2 agar materials.

— Type 3A light bodied, material formulated for syringe use in a reversible/non-reversible impression

material system, and that has been claimed to be capable of bonding to a companion alginate

impression material that will make up the greater part of an agar/alginate impression material

system.
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ISO 21563:2021(E)
5 Requirements — Characteristics and properties
5.1 General

The requirements applicable to only one category of hydrocolloid impression materials (agar or alginate)

are stated in 5.2 to 5.6. The requirements applicable to both categories are displayed in Table 1.

5.2 Consistency (agar impression materials of all Types, in the sol state only)

After being exposed to the storing temperature treatment recommended in the manufacturer’s

instructions, the material shall have a consistency that will allow the entire content of the tube or

syringes to be extruded within 30 s. No specimens need to be made but material shall be tested to see if

all can be extruded within 30s.
5.3 Working time (alginate materials only)

When tested in accordance with 7.2, the thickness of the layer of material remaining between the tip of

the test penetrator and the test base plate shall not exceed 0,25 mm.
5.4 Initial setting time (alginate materials only)

When tested in accordance with 7.3, the initial setting time shall be within 20 % of that stated in the

manufacturer’s instructions [8.2.4 h)].
5.5 Linear dimensional change (Type 3A agar materials only)

When tested in accordance with 7.9, the dimensional change shall not exceed 1,0 %.

5.6 Tensile bond strength (Type 3A agar materials only)

When tested in accordance with 7.10, the minimum tensile bond strength shall not be less than 50 kPa.

Table 1 — Other requirements for properties — Agar and alginate materials
Agar materials
Test Alginate powder
subclause Test procedure and paste/paste
Type 1 and Type 3 and
number materials
Type 2 Type 3A
7.4 Detail reproduction before and after disin- 20 20 50
fection
Line width reproduced (µm)
7.5 Compatibility with gypsum 50 50 50
Line width reproduced (µm)
7.6 Elastic recovery 96,5 96,5 95,0
% (min.)
7.7 Strain-in-compression 4,0 to 15,0 4,0 to 15,0 5,0 to 20,0
% Range: min. to max.
7.8 Tear strength 0,75 0,50 0,38
N/mm (min.)
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ISO 21563:2021(E)
6 Pre-test planning approaches
6.1 General

The information included in this clause is provided to help test operators avoid losses of time due to

trial and error efforts occurring when such information is not taken into account before test procedures

such as thos
...