Dentistry - Elastomeric impression materials
1 Scope
This standard specifies the requirements for dental elastomeric impression materials and the test methods, based on current knowledge, used to determine whether the quality of elastomeric impression materials intended for retail marketing meets their intended purposes.
This standard is applicable to dental elastomeric impression materials.
Note: This standard does not address possible biological hazards associated with the materials. Therefore, interested parties are encouraged to explore GB/T 16886 and YY/T 0127 for assessment of such hazards.
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.
GB/T 9937.1-2008 Dental vocabulary - Part 1: General and clinical terms (ISO 1942-1:1989, IDT)
GB/T 9937.2-2008 Dental vocabulary - Part 2: Dental materials (ISO 1942-2:1989, IDT)
GB/T 9937.3-2008 Dental vocabulary - Part 3: Dental instruments (ISO 1942-3:1989, IDT)
GB/T 9937.4-2005 Dental vocabulary - Part 4: Dental equipment (ISO 1942-4:1989, IDT)
GB/T 9937.5-2008 Dental vocabulary - Part 5: Terms associated with testing (ISO 1942-5:1989, IDT)
YY 0462-2018 Dentistry - Gypsum products (ISO 6873:2013, MOD)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 9937.1-2008, GB/T 9937.2-2008, GB/T 9937.3-2008, GB/T 9937.4-2005, GB/T 9937.5-2008 and the following apply.
3.1
consistency
degree of firmness with which particles of a material, prepared for use, cohere so as to allow the material to flow, or resist flow, as required to achieve the purpose for which it is intended
3.2
elastic recovery test
(elastic impression materials) method of determining whether the materials possess the elastic properties required to recover adequately after deformation occurring when the materials used for forming impressions are removed from the mouth
3.3
extrusion mixing
method by which two or more material components are extruded simultaneously from their separate primary packaging container through a special mixing tip from which the material components emerge as a homogeneous mixture
3.4
hand mixing
method of mixing the components of a material by means of manual kneading or spatulation
3.5
primary packaging
container designed to come into direct contact with the product
Note: Modified from ISO 21067:2007, 2.2.2.
3.6
mixing time
time, measured from first contact between different components of a material being mixed, required to achieve a homogeneous mixture when the components are mixed according to the manufacturer's instructions
Note: The time of first contact between extrusion-mixed material components is defined as the time when the material components can be seen entering into the mixing nozzle.
3.7
outer package
wrapping or carton, which may be required by law or a standard to bear specified labelling, used to cover one or more primary packaging in preparation for retail marketing
3.8
strain-in-compression test
(elastic impression materials) method of measuring the flexibility/stiffness property ranges of materials so as to determine whether the set materials, when formed as impressions, 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
3.9
working time
according to the recommended mixing method, period of time beginning with the commencement of mixing of the material to the time when the material begins to exhibit elastic properties that will prevent the material from being manipulated or the surface detail and dimensional characteristics of model
4 Classification
Materials covered by this standard are classified according to the following consistencies determined immediately after completion of mixing according to the manufacturer's instructions (see 5.3):
Type 0: Putty consistency;
Type 1: Heavy-bodied consistency;
Type 2: Medium-bodied consistency;
Type 3: Light-bodied consistency.
5 Requirements for packaging, labelling, and manufacturer's instructions
5.1 Packaging requirements
No packaging requirements are specified in this standard, but it is important for manufacturers to take into account that the packaging shall be such that it will not contaminate or permit contamination of ingredients of the material components during recommended storage conditions. Structure of the primary packaging shall also be such that no leakage or inadvertent extrusion of the contents can occur during storage and such that the containers will not rupture during use of the extrusion methods recommended by the manufacturer.
5.2 Labelling requirements
5.2.1 Outer packages (containing one or more primary packaging)
Labelling of the outer package prepared for retail marketing containing one or more primary packaging shall bear the following information:
a) Recommended storage conditions for the unopened package;
b) Product name;
c) Name and address of the manufacturer or the name and address of another company authorized by the manufacturer to market the material under a different brand name;
d) Consistency of the material, such as putty, heavy-bodied, medium-bodied, or light-bodied (see Clause 4) (may also be indicated by the corresponding type number);
e) Production batch number/production date;
f) Use before date, identified as such, beyond which the material may not exhibit its best properties. The date may be expressed as a six-digit number, for example, 2014-09, where the first four digits indicate the year (2014) and the last two digits indicate the month (September);
g) Minimum volume/weight that would result from mixing the entire component contents included in the outer package.
5.2.2 Primary packaging within outer package
Primary packaging shall bear the following information:
a) Product name;
b) Name of the manufacturer or name of another company authorized to market the material under a different brand name;
c) Component labelling (not required when the components for extrusion mixing are supplied in separate but joined primary packaging);
d) Production batch number/production date.
5.3 Requirements for manufacturer's instructions
5.3.1 General
Each package of impression material for retail marketing shall contain the instructions and other information needed to ensure optimum performance of the material in clinical practice.
5.3.2 Identifying information
The following identifying information shall be available:
a) Product name/(brand name);
b) Class of compounds of the elastomeric system: For example, polyethylene, polysulfide, silicone rubber (condensation type), or silicone rubber (vinyl polysiloxane, addition type).
5.3.3 Instructions for use
Where applicable, the instructions for use shall include the following:
a) Recommended storage conditions after the initial opening of the primary packaging;
b) Statements indicating that working time and other characteristics of the material can be affected significantly by the following factors, as may be applicable:
——Room temperature variations;
——Variations in the speed and friction involved in mixing;
——Hand/fingertip temperatures when kneading putty mixes;
——Moisture contamination or relative humidity;
——Contamination, either due to direct contact with latex dam or gloves used in clinical practice or due to the presence of such contaminants on teeth at the time they are impressed.
c) Proportions for hand-spatulated mixes (mass to mass and volume to volume);
d) Recommended mixing apparatus and procedures to include any hand coverings (gloves or polymer sheeting) that shall be used to avoid contamination of the materials during hand mixing;
e) Mixing time required to obtain a homogeneous mixture of an amount of the material having a volume of 15mL (see 5.3);
f) Working time;
g) Minimum time the impression shall remain in the mouth before removal;
h) Minimum or/and maximum time lapse, or both, permitted between removal of the impression from the mouth and pouring the gypsum product into the impression;
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Requirements for packaging, labelling, and manufacturer's instructions
5.1 Packaging requirements
5.2 Labelling requirements
5.3 Requirements for manufacturer's instructions
5.4 Requirements for characteristics and properties
6 Pre-test plan
7 Test methods - Specific
7.1 Mixing time
7.2 Consistency
7.3 Working time
7.4 Detail reproduction
7.5 Linear dimensional change
7.6 Compatibility with gypsum
7.7 Elastic recovery
7.8 Strain-in-compression
Annex A (Normative) Figures cited in this standard
Annex B (Normative) Standardized hand mixing methods
Annex C (Informative) Working-time test apparatus components - Possible sources
Bibliography
