SIST EN ISO 6873:2013

SLOVENSKI STANDARD
01-september-2013
1DGRPHãþD
SIST EN ISO 6873:2000
=RER]GUDYVWYR0DYþQLL]GHONL,62
Dentistry - Gypsum products (ISO 6873:2013)
Zahnheilkunde - Gipse (ISO 6873:2013)
Médecine bucco-dentaire - Produits à base de gypse (ISO 6873:2013)
Ta slovenski standard je istoveten z: EN ISO 6873:2013
ICS:
11.060.10 =RERWHKQLþQLPDWHULDOL Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 6873
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2013
ICS 11.060.10 Supersedes EN ISO 6873:2000
English Version
Dentistry - Gypsum products (ISO 6873:2013)
Médecine bucco-dentaire - Produits à base de gypse (ISO Zahnheilkunde - Gipse (ISO 6873:2013)
6873:2013)
This European Standard was approved by CEN on 21 March 2013.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6873:2013: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 6873:2013) 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 October 2013, and conflicting national standards shall be withdrawn at
the latest by October 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 6873:2000.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 6873:2013 has been approved by CEN as EN ISO 6873:2013 without any modification.

INTERNATIONAL ISO
STANDARD 6873
Third edition
2013-04-01
Dentistry — Gypsum products
Médecine bucco-dentaire — Produits à base de gypse
Reference number
ISO 6873:2013(E)
©
ISO 2013
ISO 6873:2013(E)
© ISO 2013
All rights reserved. Unless otherwise specified, 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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Tel. + 41 22 749 01 11
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E-mail copyright@iso.org
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Published in Switzerland
ii © ISO 2013 – All rights reserved

ISO 6873:2013(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 1
5 Requirements . 2
5.1 Quality . 2
5.2 Fluidity at pouring time (Type 1 materials only) . 2
5.3 Setting time . 2
5.4 Linear setting expansion . 2
5.5 Fracture (Type 1 materials only) . 2
5.6 Compressive strength . 2
5.7 Reproduction of detail . 2
6 Testing — Generalities . 3
6.1 Sampling . 3
6.2 Test conditions . 3
6.3 Mixing method . 3
7 Test methods . 3
7.1 Visual inspection . 3
7.2 Fluidity at pouring time for Type 1 materials . 3
7.3 Setting time . 4
7.4 Linear setting expansion . 7
7.5 Fracture .12
7.6 Compressive strength .12
7.7 Reproduction of detail .13
8 Packaging, marking and information to be supplied by the manufacturer .18
8.1 Packaging .18
8.2 Labelling .18
8.3 Instructions for use .19
ISO 6873:2013(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
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.
Specific qualitative and quantitative requirements for freedom from biological hazard are not included
in this International Standard but it is recommended that, in assessing possible biological hazards,
reference should be made to ISO 10993-1 and ISO 7405.
ISO 6873 was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2,
Prosthodontic materials.
This third edition cancels and replaces the second edition (ISO 6873:1998) of which Clause 4 and
subclauses 5.4 and 8.2 have been technically revised. An alternative design for the extensometer used
to measure setting expansion is included.
iv © ISO 2013 – All rights reserved

ISO 6873:2013(E)
Introduction
This revision was necessary because gypsum products have been marketed since the last edition of
ISO 6873 was published, which have properties (required for newly introduced dental technology) for
which the requirements set in that edition were not appropriate. In this edition the classification has
been altered to take this into account and in so doing, requirements have been set appropriately. In
addition there was concern that Type 4 dental stone used for CAD/CAM models should not produce
significant setting expansion at times beyond the 2 h period at which setting expansion was measured
and a requirement had been set. In this edition the setting expansion for Type 4 dental stone is measured
at 24 h as well.
INTERNATIONAL STANDARD ISO 6873:2013(E)
Dentistry — Gypsum products
1 Scope
This International Standard gives a classification of, and specifies requirements for, gypsum products
used for dental purposes such as making oral impressions, moulds, casts, dies or model bases, and
mounting models. It specifies the test methods to be employed to determine compliance with these
requirements. It also includes requirements for the labelling of packaging and for adequate instructions
to accompany each package.
This International Standard does not apply to dental bone graft substitutes composed of calcium sulfate
hemihydrate (or gypsum).
2 Normative references
The following referenced documents are indispensable for the application 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 1302, Geometrical Product Specifications (GPS) — Indication of surface texture in technical product
documentation
ISO 1942, Dentistry — Vocabulary
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 8601, Data elements and interchange formats — Information interchange — Representation of
dates and times
ISO 15223-1, Medical devices — Symbols to be used with medical device labels, labelling and information to
be supplied — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
3.1
gypsum product
dental product composed essentially of a hemihydrate of calcium sulfate and any necessary modifiers
Note 1 to entry: Colouring matter and flavouring, if present, are regarded as necessary modifiers.
4 Classification
The five types of gypsum product used in dentistry are classified in accordance with this International
Standard as follows:
a) Type 1: Dental plaster for impressions;
b) Type 2: Dental plaster for mounting (Class 1) and for models (Class 2);
c) Type 3: Dental stone for models;
d) Type 4: Dental stone (high strength, low expansion) for dies, model bases and CAD/CAM dies;
ISO 6873:2013(E)
e) Type 5: Dental stone (high strength, high expansion) for dies when this degree of expansion is
necessary for shrinkage compensation of some materials used in dental restoration.
5 Requirements
5.1 Quality
When tested according to 7.1, the powder shall be uniform and free from foreign matter and lumps. When
mixed according to the manufacturer’s instructions the product shall produce a homogeneous mix.
5.2 Fluidity at pouring time (Type 1 materials only)
When tested according to 7.2 at a pouring time of 1,25 min, the fluidity of type 1 materials shall be equal
to or greater than 70 mm.
5.3 Setting time
When tested according to 7.3, the setting time of type 1 materials shall be in the range of 2,5 min to
5,0 min and the setting time of all material types shall be within 20 % of the value claimed by the
manufacturer in 8.2.1 h) or 8.2.2 h), whichever is appropriate for the packaging in which the product is
supplied. If the manufacturer claims a range of setting time, then the midpoint of this range is taken as
the value claimed by the manufacturer.
5.4 Linear setting expansion
When tested according to 7.4, the linear setting expansion shall be within the range listed in Table 1.
Table 1 — Linear setting expansion and compressive strength
Type Linear setting expansion Compressive strength
% MPa
2 h 24 h 1 h
min. max. min. max. min. max.
1 0,00 0,15 - - 4,0 8,0
2 (Class 1) 0,00 0,05 - - 9,0 -
2 (Class 2) 0,06 0,30 - - 9,0 -
3 0,00 0,20 - - 20,0 -
4 0,00 0,15 0,00 0,18 35,0 -
5 0,16 0,30 - - 35,0 -
5.5 Fracture (Type 1 materials only)
When tested according to 7.5, Type 1 impression plaster shall break with a clean fracture and be readily
reassembled to form the shape and size of the original unbroken specimen.
5.6 Compressive strength
When tested according to 7.6, the compressive strength shall meet the requirement(s) of Table 1.
5.7 Reproduction of detail
Types 1 and 2: When tested according to 7.7, groove c in Figure 6 shall be reproduced.
Types 3, 4 and 5: When tested according to 7.7, groove a in Figure 6 shall be reproduced.
2 © ISO 2013 – All rights reserved

ISO 6873:2013(E)
6 Testing — Generalities
6.1 Sampling
Select the material for testing from one lot that has been produced for retail and that is not beyond
its expiry date [8.2.1 b) or 8.2.2 b), whichever is appropriate for the packaging in which the product is
supplied]. Do not use powder from previously opened, broken or damaged containers.
6.2 Test conditions
Carry out all mixing and testing of the dental gypsum product at (23 ± 2) °C and (50 ± 10) % relative
humidity. Ensure that all apparatus and instruments used in mixing and testing are clean, dry and free
from particles of gypsum. Before testing begins, hold material and test apparatus at the test temperature
for a period of time that is sufficient to equilibrate with this temperature.
NOTE A minimum storage period of 15 h is recommended.
6.3 Mixing method
Mix by one of the methods (hand or mechanical) specified by the manufacturer in the instructions (see
8.3), using water, which meets the requirements of ISO 3696, Grade 3.
7 Test methods
7.1 Visual inspection
Carry out visual inspection without magnification to determine compliance with the requirements
given in 5.1, 5.5 and 5.7 (unless as stated otherwise, as in 7.7).
Determine compliance with the requirements given in Clause 8 for packaging, marking and information
supplied by the manufacturer.
7.2 Fluidity at pouring time for Type 1 materials
7.2.1 Apparatus
7.2.1.1 Cylindrical mould, constructed from a corrosion-resistant, non-absorbent material, having a
length of (50,0 ± 0,1) mm and an inside diameter of (35,0 ± 0,1) mm. Clean and dry.
7.2.1.2 Glass plate, flat and smooth, with sides of length at least 100 mm. Clean and dry.
7.2.1.3 Means of measuring lengths from 35 mm to 100 mm, for measuring the major and minor
diameters of the slumped mix to the nearest millimetre.
7.2.2 Procedure
Rest the glass plate on a surface that is free of vibration. Place the mould upright on the centre of the plate.
Add (100,0 ± 0,1) g of the sample to the manufacturer’s recommended quantity of water (ISO 3696,
Grade 3) dispensed to an accuracy of 0,1 ml to a mixing bowl and mix as described in 6.3.
Completely fill the mould and level off the mixed material so that it is flush with the top of the mould.
At 1,25 min after the start of mixing, lift the mould vertically from the plate at a rate of approximately
10 mm/s and allow the mix to slump or spread over the plate. One minute after the mould is lifted,
measure the major and minor axes of the slumped material to the nearest millimetre. Record the average
of these two diameters as the fluidity at the pouring time.
ISO 6873:2013(E)
7.2.3 Evaluation
Carry out the test twice. If both average values meet the requirement given in 5.2, then the product
meets the requirement for fluidity. If neither meets this requirement, then the product fails. If one
average value meets the requirement given in 5.2, and the other fails, carry out three more tests. If all
three of these average values meet the requirement given in 5.2, the product meets the requirement for
fluidity. Otherwise it fails.
7.3 Setting time
7.3.1 Apparatus
7.3.1.1 Needle penetrometer, an example of which is shown in Figure 1, meeting the following
requirements:
a) Penetrometer needle (1), 50 mm long, of circular cross-section, with a diameter of (1,00 ± 0,05) mm
and a squared end.
b) Rod (2), of approximate dimensions 270 mm long and 10 mm in diameter.
c) Additional (compensating) weight (3).
d) The total mass of all the parts that move with the rod shall be (300 ± 1) g.
e) Scale (4), graduated in millimetres.
f) Base-plate (5) of plate glass, measuring about 100 mm × 100 mm.
4 © ISO 2013 – All rights reserved

ISO 6873:2013(E)
X
X
1 1
Key
1 Needle 5 Base plate
2 Rod 6 Stand
3 Additional (compensating) weight 7 Scale adjustment locking screw
4 Scale 8 Mould
Figure 1 — Example of needle penetrometer
7.3.1.2 Ring mould, constructed from a corrosion-resistant, non-absorbent material. There are two
alternatives.
7.3.1.2.1 Large conical mould, with an inside diameter of 70 mm at the top and 60 mm at the base, and
a height of 40 mm.
ISO 6873:2013(E)
7.3.1.2.2 Small cylindrical mould, with an inside diameter of 20 mm and height of 30 mm.
NOTE For effective utilization of resources, the smaller mould can be used in the place of the traditional larger
mould. The user will be aware that the decreased area allows fewer indentation sites [according to 7.3.2] and that
greater attention must be given to the time (relative to the anticipated setting time) of the first indentation.
7.3.1.3 Mould release agent, such as silicone spray or silicone grease.
7.3.2 Procedure
Coat the inside of the ring mould with a thin layer of mould release agent. Place the ring mould on the
base-plate, positioned to
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