oSIST prEN ISO 20795-1 rev:2026

SLOVENSKI STANDARD
01-junij-2026
Zobozdravstvo - Osnovni polimeri - 1. del: Osnovni polimeri za proteze (ISO/DIS
20795-1:2026)
Dentistry - Base polymers - Part 1: Denture base polymers (ISO/DIS 20795-1:2026)
Zahnheilkunde - Kunststoffe - Teil 1: Prothesenkunststoffe (ISO/DIS 20795-1:2026)
Médecine bucco-dentaire - Polymères de base - Partie 1: Polymères pour base de
prothèses dentaires (ISO/DIS 20795-1:2026)
Ta slovenski standard je istoveten z: prEN ISO 20795-1 rev
ICS:
11.060.10 Zobotehnični materiali Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 20795-1
ISO/TC 106/SC 2
Dentistry — Base polymers —
Secretariat: ANSI
Part 1:
Voting begins on:
Denture base polymers 2026-04-22
Voting terminates on:
Médecine bucco-dentaire — Polymères de base —
2026-07-15
Partie 1: Polymères pour base de prothèses dentaires
ICS: 11.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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.
Reference number
ISO/DIS 20795-1:2026(en)
DRAFT
ISO/DIS 20795-1:2026(en)
International
Standard
ISO/DIS 20795-1
ISO/TC 106/SC 2
Dentistry — Base polymers —
Secretariat: ANSI
Part 1:
Voting begins on:
Denture base polymers
Voting terminates on:
Médecine bucco-dentaire — Polymères de base —
Partie 1: Polymères pour base de prothèses dentaires
ICS: 11.060.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 20795-1:2026(en)
ii
ISO/DIS 20795-1:2026(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classification . 4
5 Requirements . 4
5.1 Unpolymerized material .4
5.1.1 Liquid component, Type 1 and 2 .4
5.1.2 Powder component, Type 1 and 2 .5
5.1.3 Material for additive manufacturing, Type 4 Class 2.5
5.1.4 Packing plasticity, Type 1 Class 1, Type 1 Class 2, Type 2, Type 4 Class 1 and
Type 5 materials .5
5.2 Polymerized material .5
5.2.1 Biocompatibility .5
5.2.2 Surface characteristics .5
5.2.3 Shape capability .5
5.2.4 Colour .5
5.2.5 Colour stability.6
5.2.6 Translucency .6
5.2.7 Freedom from porosity .6
5.2.8 Ultimate flexural strength.6
5.2.9 Flexural modulus .6
5.2.10 Maximum stress intensity factor for materials with improved impact resistance .6
5.2.11 Total fracture work .6
5.2.12 Bonding to synthetic polymer teeth .6
5.2.13 Residual methyl methacrylate monomer .6
5.2.14 Sorption .7
5.2.15 Solubility .7
6 Sampling . 7
7 General test conditions . 8
8 Test methods . 8
8.1 Inspection for compliance determination .8
8.1.1 Visual inspection .8
8.1.2 Expression of results .8
8.2 Packing plasticity .8
8.2.1 Materials .8
8.2.2 Apparatus .8
8.2.3 Procedure .9
8.2.4 Pass/fail determinations .10
8.2.5 Expression of results .10
8.3 Colour .10
8.3.1 General .10
8.3.2 Expression of results .10
8.4 Colour stability .10
8.4.1 Materials .10
8.4.2 Apparatus .10
8.4.3 Preparation of test specimens .11
8.4.4 Procedure .11
8.4.5 Expression of results .11
8.5 Polishability, translucency, freedom from porosity, ultimate flexural strength, and
flexural modulus .11

iii
ISO/DIS 20795-1:2026(en)
8.5.1 Polishability .11
8.5.2 Translucency . 12
8.5.3 Freedom from porosity, ultimate flexural strength, and flexural modulus. 13
8.6 Fracture toughness with a modified bending test, if claimed . 15
8.6.1 General . 15
8.6.2 Materials . 15
8.6.3 Apparatus . 15
8.6.4 Procedure .16
8.6.5 Calculation and expression of the results .18
8.7 Bonding to synthetic polymer teeth.19
8.7.1 Apparatus and materials .19
8.7.2 Preparation .19
8.7.3 Test procedure.19
8.7.4 Pass/fail determination .19
8.7.5 Expression of results . 20
8.8 Residual methyl methacrylate monomer . 20
8.8.1 Principle . 20
8.8.2 Preparation of test specimen discs . 20
8.8.3 Extraction of monomer .21
8.8.4 Gas chromatography . 22
8.8.5 Calculation and expression of results. 23
8.9 Water sorption and solubility . 25
8.9.1 Materials . 25
8.9.2 Apparatus . 25
8.9.3 Preparation of test specimens . 25
8.9.4 Procedure . 25
8.9.5 Calculation and expression of results. 26
9 Requirements for labelling, marking, packaging, and instructions supplied by the
manufacturer .27
9.1 Packaging .27
9.2 Marking and instructions for use .27
Annex A (normative) HPLC method for determination of MMA content .29
Annex B (normative) Specimen preparation .32
Bibliography .40

iv
ISO/DIS 20795-1:2026(en)
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.
This document was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2,
Prosthodontic materials.
This third edition cancels and replaces the second edition (ISO 20795-1:2013), which has been technically
revised.
The following main changes have been made to the document:
— Updated Scope, Terms and definitions, and Classification for the inclusion of additively and subtractively
manufactured materials
— Addition of Annex B, where preparation procedures are extracted from previous main document and
added for new types/classes
— Introduction of ISO TS 19736 as supplemental method for evaluation of bonding to synthetic teeth
—
ISO 20795 consists of the following parts, under the general title Dentistry — Base polymers:
— Part 1: Denture base polymers
— Part 2: Orthodontic base polymers

v
ISO/DIS 20795-1:2026(en)
Introduction
Since the first editions of this standard, many developments have been made concerning materials used for
the denture bases as well as for the technical processing of these materials. This revision of the standard was
started with the aim to include, in more clarity, some new materials and processing techniques, in particular
CAD-CAM using additive manufacturing (e.g. vat photopolymerization) and subtractive manufacturing
(automated milling). Softer or more elastic thermoplastic materials (e.g. polyamide) are neither specifically
included nor excluded from this document.
Specific qualitative and quantitative requirements for freedom from biological hazard are not included
in this document, but it is recommended that, in assessing possible biological or toxicological hazards,
reference be made to ISO 10993-1 and ISO 7405.

vi
DRAFT International Standard ISO/DIS 20795-1:2026(en)
Dentistry — Base polymers —
Part 1:
Denture base polymers
1 Scope
1.1 This document classifies denture base polymers, including materials for additive and subtractive
manufacturing, and specifies their requirements. It also specifies the test methods to be used in determining
compliance with these requirements. It further specifies requirements with respect to packaging and
marking the products and to the instructions to be supplied for use of these materials. Furthermore, it
applies to denture base polymers for which the manufacturer claims that the material has improved impact
resistance. It also specifies the respective requirement and the test method to be used.
1.2 Although this document does not require manufacturers to declare details of the composition,
attention is drawn to the fact that some national or international authorities require such details to be
provided.
NOTE 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 463, Geometrical Product Specifications (GPS) — Dimensional measuring equipment — Design and
metrological characteristics of mechanical dial gauges
ISO 1942, Dentistry — Vocabulary
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 6344-2, Coated abrasives — Determination and designation of grain size distribution — Part 2: Macrogrit
sizes P12 to P220
ISO 6344-3, Coated abrasives — Determination and designation of grain size distribution — Part 3: Microgrit
sizes P240 to P5 000
ISO 7491, Dental materials — Determination of colour stability
ISO 8601-1:2019, Date and time — Representations for information interchange — Part 1: Basic rules
ISO 15223-1:2021, Medical devices — Symbols to be used with information to be supplied by the manufacturer
— Part 1: General requirements
ISO 22112:2017, Dentistry — Artificial teeth for dental prostheses
ISO/TS 19736:2017, Dentistry — Bonding test between polymer teeth and denture base materials

ISO/DIS 20795-1:2026(en)
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 https:// www .electropedia .org/
3.1
materials for additive manufacturing
polymer-based materials, with or without fillers, for production of denture base by additive manufacturing
3.2
3D printing
fabrication of objects by vat polymerization or through the deposition of a material using a print head, nozzle
or another printer technology
[SOURCE: ISO/ASTM 52900:2021, 3.3.1, modified – addition of vat polymerization]
Note 1 to entry: This term is often used in a non-technical context synonymously with additive manufacturing (3.3)
and, in these cases, typically associated with machines used for non-industrial purposes including personal use.
3.3
additive manufacturing (AM)
process of joining materials to make dentures from 3D model data, usually layer upon layer, as opposed to
subtractive manufacturing and formative manufacturing methodologies
[SOURCE: ISO/ASTM 52900:2021, 3.1.2, modified - Note 1 and Note 2 to entry have been deleted.]
3.4
autopolymerizable materials
products having polymerization initiated by chemical means and not requiring application of temperatures
above 65 °C nor any other energy source to complete the polymerization
3.5
capsulated material
material consisting of two or more components supplied in a container that keeps them separated until the
time they are mixed together and dispensed for use directly from the container
3.6
curing
changing of the physical properties of a material by means of a chemical reaction
[SOURCE: ISO/ASTM 52900:2021, 3.6.9, modified – from “cure” to “curing”]
Note 1 to entry: One of the most important curing operations in additive manufacturing is the changing of a polymer
resin from liquid to solid by light-activated cross-linking of molecule chains.
3.7
denture
dental device replacing one or more missing teeth and, if required, associated anatomical structures
[SOURCE: ISO 1942:2020, 3.3.1.19]
3.8
denture base
that part of a denture which rests on soft tissue foundations and to which artificial teeth are added

ISO/DIS 20795-1:2026(en)
3.9
denture base disc or blank
pre-cured polymer-based materials, with or without fillers, delivered as discs or blocks, intended for
production of denture base by subtractive manufacturing
3.10
feedstock
bulk raw material supplied to the additive manufacturing building process
[SOURCE: ISO/ASTM 52900:2021, 3.6.5]
3.11
final packing time
last time, after achievement of the initial packing time, at which a denture base material mixture retains
packing consistency
3.12
heat-polymerizable materials
products requiring application of temperatures above 65 °C to complete polymerization
3.13
immediate container
container that is in direct contact with the denture base materials
3.14
initial packing time
time after mixing, or other preparation, when a denture base material mixture first reaches packing
consistency
3.15
liquid
monomeric liquid to be mixed with polymeric particles to form a mouldable dough or fluid resin mixture
used for forming denture bases
3.16
outer packaging
labelled container or wrapping within which other containers are packed
3.17
packing
act of filling a denture base mould with a material (using a compression, pour, or injection
technique) to form a denture base
3.18
post-processing
process steps, or series of process steps, taken after the completion of an additive manufacturing build cycle
in order to achieve the desired properties in the final product
[SOURCE: ISO/ASTM 52900:2021, 3.6.10]
3.19
powder
polymeric particles to be mixed with monomeric liquid to form a mouldable dough or fluid resin mixture
used for forming denture bases, i.e. the powder & liquid-technique
3.20
processing
complete procedure of preparing a solid denture base polymer plate and/or specimen

ISO/DIS 20795-1:2026(en)
3.21
subtractive manufacturing
process of machining, grinding, or reducing a larger bulk object to create a smaller detailed three-
dimensional object using computer aided design software and computer aided manufacturing methods
[SOURCE: ISO 23704-1:2022, 3.1.29]
3.22
thermoplastic
characteristic of a hard polymeric material that allows it to be softened by application of heat to make it
mouldable, and then return to the hardened state upon cooling
3.23
translucency
capacity of a body of material to allow the passage of light, yet diffusing the light so as not to render objects
lying beyond the body clearly visible
3.24
vat photopolymerization
additive manufacturing process in which liquid photopolymer in a vat is selectively cured by light-activated
polymerization
[SOURCE: ISO/ASTM 52900:2021, 3.6.7]
4 Classification
Denture base polymers covered by this document are categorized into the following types and classes:
— Type 1: Heat-polymerizable materials
— Class 1: Powder and liquid
— Class 2: Premixed paste-like materials
— Type 2: Autopolymerizable materials
NOTE Autopolymerizable materials can be powder and liquid for packing technique, and powder and liquid for
pouring or injection technique
— Type 3: Thermoplastic materials
NOTE Thermoplastic materials can be delivered as thermoformable plates, pellets for injection or filaments for
additive manufacturing.
— Type 4: Photo-activated materials
— Class 1: Paste-like materials
— Class 2: Materials for additive manufacturing
— Type 5: Microwave cured materials
— Type 6: Materials for subtractive manufacturing
5 Requirements
5.1 Unpolymerized material
5.1.1 Liquid component, Type 1 and 2
The liquid shall be free of deposit or sediment that can be observed by visual inspection (see 8.1.1).

ISO/DIS 20795-1:2026(en)
5.1.2 Powder component, Type 1 and 2
The powder components shall be free of extraneous material that can be observed by visual inspection (see
8.1.1).
5.1.3 Material for additive manufacturing, Type 4 Class 2
The feedstock must become homogenous by visual inspection (see 8.1.1) when stirred and/or shaken in
accordance with the manufacturer’s instructions.
NOTE The resin can contain fillers, and these should be evenly distributed after stirring.
5.1.4 Packing plasticity, Type 1 Class 1, Type 1 Class 2, Type 2, Type 4 Class 1 and Type 5 materials
When Type 1 Class 1, Type 2 and Type 4 Class 1 materials are tested in accordance with 8.2, at the initial
packing time recommended by the manufacturer, they shall be capable of being intruded into at least two
holes in the die (8.2.2.1) to a depth of not less than 0,5 mm (see 8.2.3.2). Type 1 Class 1, Type 1 Class 2, and
Type 5 materials shall meet the requirements when tested at the final packing time (see 8.2.3.3).
5.2 Polymerized material
5.2.1 Biocompatibility
Specific qualitative requirements for freedom from biological hazard are not included in this document,
but it is recommended that, in assessing possible biological or toxicological hazards, reference be made to
ISO 10993-1 and ISO 7405.
5.2.2 Surface characteristics
5.2.2.1 When processed in the manner recommended by the manufacturer and in contact with materials
recommended by the manufacturer, denture base specimens prepared for colour stability, for residual
methyl methacrylate monomer, and for sorption and solubility testing shall have a smooth, hard, and glossy
surface (see 8.1.1).
5.2.2.2 The processed test specimens shall retain their form without visible distortion after processing
(see 8.1.1).
5.2.2.3 When polished in accordance with 8.5.1.3, the specimen plates shall present a smooth surface with
a high gloss (see 8.1.1).
5.2.3 Shape capability
When prepared in accordance with the manufacturer’s instructions, all types of denture base polymers
shall produce a test specimen or a specimen plate with defined edges (see 8.1.1).
5.2.4 Colour
The colour of a specimen strip shall be as stated by the manufacturer when tested in accordance with 8.3
and inspected in accordance with 8.1.1.
Coloured denture base polymers shall be translucent (see 5.2.6 and 8.5.2) and pigment and fibres shall be
evenly distributed.
Clear (transparent) denture base polymers shall be clear and colourless.

ISO/DIS 20795-1:2026(en)
5.2.5 Colour stability
When tested in accordance with 8.4 and inspected in accordance with 8.1.1, test specimens shall not show
more than a slight change in colour.
5.2.6 Translucency
Where a manufacturer claims translucency, when tested in accordance with 8.5.2 the shadow of the
illuminated opaque disc shall be visible from the opposite side of the test specimen plate.
5.2.7 Freedom from porosity
When prepared in accordance with manufacturer’s instructions and 8.5.3.3, a specimen’s strips shall not
show voids that can be observed by visual inspection (see 8.1.1).
5.2.8 Ultimate flexural strength
When determined in accordance with 8.5.3.4, the ultimate flexural strength shall be not less than 65 MPa
for Type 1, Type 3, Type 4, Type 5, and Type 6 polymers and not less than 60 MPa for Type 2 polymers (see
Table 1).
5.2.9 Flexural modulus
When determined in accordance with 8.5.3.5, the flexural modulus of the processed polymer shall be at
least 2 000 MPa for Type 1, Type 3, Type 4, Type 5, and Type 6 polymers and at least 1 500 MPa for Type 2
polymers (see Table 1).
5.2.10 Maximum stress intensity factor for materials with improved impact resistance
Where a manufacturer claims a material with improved impact resistance, the maximum stress intensity
1/2
factor shall be at least 1,9 MPa m when tested in accordance with 8.6 (see Table 2).
5.2.11 Total fracture work
Where a manufacturer claims a material with improved impact resistance, the total fracture work shall be
at least 900 J/m when tested in accordance with 8.6 (see Table 2).
5.2.12 Bonding to synthetic polymer teeth
Denture base polymers intended for use with synthetic polymer teeth shall meet one of the following
requirements:
a) When tested in accordance with 8.7, or with the bonding requirements of ISO 22112, the set-up shall
produce cohesive failures; or
b) When tested according to ISO TS 19736, the set-up shall produce cohesive failures; or
c) If there are problems of achieving bonding through the above methods, the manufacturer’s instructions
shall contain information about special treatments necessary to achieve bonding [see 9.3 n)]. A test set-
up shall be prepared following the manufacturer’s instructions. When tested, the set-up shall produce
cohesive failures between base and teeth.
The requirement for bonding to synthetic polymer teeth is not applicable to denture discs or blanks where
base and teeth are combined in one disc for subtractive manufacturing.
5.2.13 Residual methyl methacrylate monomer
When prepared and tested in accordance with 8.8, the following shall apply (see Table 1).

ISO/DIS 20795-1:2026(en)
The upper limit (maximum) for residual methyl methacrylate is 2,2 % mass fraction for denture base
polymers of Type 1, Type 3, Type 4, Type 5, and Type 6.
The upper limit (maximum) for residual methyl methacrylate is 4,5 % mass fraction for denture base
polymers of Type 2.
If lower percentages of residual methyl methacrylate monomer are claimed by the manufacturer [see 9.3 o)],
the content shall not be more than 0,2 % mass fraction higher than that stated by the manufacturer.
NOTE If a material does not contain methyl methacrylate, the test is not relevant.
5.2.14 Sorption
When the processed polymer is tested in accordance with 8.9, the increase in mass per volume (water
sorption) shall not exceed 32 µg/mm (see Table 1).
5.2.15 Solubility
When the processed polymer is tested in accordance with 8.9, the loss in mass (soluble matter) per volume
shall not exceed 1,6 µg/mm for Type 1, Type 3, Type 4 Class 1, Type 5, and Type 6 polymers and shall not
exceed 8,0 µg/mm for Type 2 and Type 4 Class 2 polymers (see Table 1).
Table 1 — Summary of requirements described in 5.2.8, 5.2.9, 5.2.13, 5.2.14, and 5.2.15
Residual methyl meth-
Flexural properties acrylate Sorption Solubility
monomer
Ultimate
Flexural
flexural
Requirements
modulus
strength
σ E w w
sp sl
3 3
MPa MPa Percent mass fraction µg/mm µg/mm
min. min. max. max. max.
Types 1, 3, 4 Class 1, 5, 6 65 2 000 2,2 32 1,6
Type 2, Type 4 Class 2 60 1 500 4,5 32 8,0
Table 2 — Additional requirements for materials with improved impact resistance described in
5.2.10 and 5.2.11
Fracture toughness
Maximum stress inten-
Total fracture work
sity factor
Requirements
K W
max f
1/2 2
MPa m J/m
min. min.
Materials with improved im-
1,9 900
pact resistance
6 Sampling
The test sample shall consist of a retail package, or packages, containing sufficient material to carry out
the specified tests, plus an allowance for any necessary repetition of the tests. If more than one package is
required, all material shall be of the same batch.

ISO/DIS 20795-1:2026(en)
7 General test conditions
Specimens shall be prepared according to Annex B.
Laboratory environment shall be (23 ± 2) °C and (50 ± 20) % relative humidity, unless otherwise specified
in this document or in the manufacturer's instructions. Materials and apparatus shall be equilibrated in the
laboratory environment unless otherwise specified in this document or in the manufacturer's instructions.
8 Test methods
8.1 Inspection for compliance determination
8.1.1 Visual inspection
Observe the test samples by visual inspection to determine compliance with the requirements laid down in
5.1.1, 5.1.2, 5.1.3, 5.2.2, 5.2.3, 5.2.4, 5.2.5, 5.2.7 and Clause 9 [inspect for colour (5.2.4) and colour stability
(5.2.5) in accordance with ISO 7491].
8.1.2 Expression of results
Report whether the liquid components pass or fail (see 5.1.1).
Report whether the solid components pass or fail (see 5.1.2).
Report whether the material for additive manufacturing pass or fail (see 5.1.3).
Report whether the surfaces of the denture base specimens have a smooth, hard, and glossy surface (see
5.2.2.1), and whether the specimens pass or fail.
Report whether the form of specimens is retained without distortion and whether the specimens pass or fail
(see 5.2.2.2).
Report whether the specimen plates have a smooth surface with a high gloss after polishing and whether the
specimen plate passes or fails (see 5.2.2.3).
Report whether the specimen plate has defined edges and whether the specimen plate passes or fails (see
5.2.3).
Report whether the material passes or fails the requirements for labelling, marking, packaging, and
instructions (see Clause 9).
8.2 Packing plasticity
8.2.1 Materials
8.2.1.1 Polyethylene or polyester film, 0,035 mm to 0,050 mm thick and approximately 50 mm × 50 mm.
8.2.1.2 Glass plate, (60 ± 5) mm × (60 ± 5) mm × (5 ± 1) mm.
8.2.2 Apparatus
8.2.2.1 Perforated brass die, having the dimensions shown in Figure 1, with perforations having a
diameter of (0,75 ± 0,05) mm.
ISO/DIS 20795-1:2026(en)
Dimensions in millimetres
Dimensional tolerances not specified shall be ±1 mm.
Figure 1 — Perforated brass die for packing plasticity test
8.2.2.2 Weight, capable of exerting a force of (50 ± 1) N.
8.2.2.3 Dial gauge, complying with ISO 463, or linear gauge accurate to 0,01 mm, equipped with a probe
capable of entering holes in the brass die for measuring depth of penetration of the material into the die.
8.2.3 Procedure
8.2.3.1 General
The materials are tested at the times following mixing as shown in Table 3. See 3.11 and 3.14 for packing
time definitions.
Table 3 — Testing procedure
Type 1 Type 1 Type 4
Type 2 Type 5
Class 1 Class 2 Class 1
Initial packing time × — × x —
Final packing time × × — — ×
8.2.3.2 Initial packing time for Type 1 Class 1 and Type 2
Prepare a sample of the material having a mass of 16 g to 20 g. Immediately prior to the manufacturer's
recommended initial packing time [see 9.3 e)], immediately shape one-half of the sample into a cake
approximately 5 mm thick, place it on the upper surface of the brass die (8.2.2.1), and cover it with a plastic
film (8.2.1.1). At the recommended initial packing time, place the glass plate (8.2.1.2) and the weight

ISO/DIS 20795-1:2026(en)
(8.2.2.2) on the plastic-covered resin cake. After 10 min ± 30 s, remove the weight. When the material is
firm, introduce the measuring instrument probe (8.2.2.3) into each hole from the other side of the brass die
to contact the penetrating material to determine the unpenetrated depth in the hole.
Calculate the depth of penetration for each hole according to the following formula:
Ddd
p
where
D is the depth of penetration, in millimetres;
p
d is the thickness of the brass die, in millimetres;
′
d is the depth not penetrated, in millimetres.
8.2.3.3 Final packing time for Type 1 Class 1, Type 1 Class 2, and Type 5
Immediately before the final packing time [see 9.3 e)] recommended by the manufacturer, immediately
shape the second half of the sample into a cake and test this portion in accordance with 8.4.
...