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YY 0271 consists of the following parts, under the general title Dentistry - Water-based cements:
——Part 1: Powder/liquid acid-base cements
——Part 2: Resin-modified cements
This part is Part 1 of YY 0271.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces YY 0271.1-2009 Dentistry - Water-based cements - Part 1: Powder/liquid acid-base cements.
The following main technical changes have been made with respect to YY 0271.1-2009:
——Test and requirements for radio-opacity are added;
——Requirements for manufacturer’s instructions for hand-mixed cements and those for capsulated cements are distinguished;
——Test and requirements for opacity are added;
——Test and requirements for colour are added;
——The basis for determination of arsenic contents is changed from "in accordance with the method specified in Pharmacopoeia of the People's Republic of China (Edition 2005)" to “determine the arsenic content in accordance with the method (arbitration method) given in ISO 2590 or specified in Pharmacopoeia of the People's Republic of China (Edition 2010)”’;
——Water for analytical laboratory use is changed from “deionized water or distilled water” to “grade 3 water as defined in ISO 3696:1987 according to ISO 9917-1:2007”;
——Bibliography is added.
This part is modified in relation to ISO 9917-1:2007 Dentistry - Water-based cements - Part 1: Powder/liquid acid-base cements.
The main differences between this part and ISO 9917-1:2007 are as follows:
——8.5 a), together with the contents therein, in ISO 9917-1:2007 is deleted;
——Annex F is divided into Annex F (informative) and Annex G; the serial number of any of the remaining annex is changed to the one right behind it accordingly.
——As for the determination of arsenic contents, the contents of “determine the arsenic content in accordance with the method specified in Pharmacopoeia of the People's Republic of China (Edition 2010)” are added.
The documents, referenced in this part, which corresponds to those in the international standard, are as below:
——GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods (ISO 3696:1987, MOD);
——YY/T 0631-2008 Dental materials - Determination of colour stability (ISO 7491:2000, IDT).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This part was proposed by the China State Food and Drug Administration.
This part is under the jurisdiction of National Technical Committee on Dental Materials and Equipment of Standardization Administration of China (SAC/TC 99).
The previous editions replaced by this part are as follows:
——YY 0271-1995, YY 0271.1-2009.
Introduction
Specific qualitative and quantitative requirements for freedom from biological hazard are not included in this part, but it is recommended that, in assessing possible biological or toxicological hazards, reference should be made to ISO 7405 and ISO 10993-1.
Dentistry - Water-based cements -
Part 1: Powder/liquid acid-base cements
1 Scope
This part of YY 0271 specifies requirements and test methods for powder/liquid acid-base dental cements intended for permanent cementation, lining and restoration. This part of YY 0271 is applicable to both hand-mixed and capsulated cements for mechanical mixing.
This part specifies limits for each of the properties according to whether the cement is intended for use as a luting agent, a base or liner or as a restorative material. This part is not intended to address resin-modified water-based cements.
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 2590 General method for the determination of arsenic - Silver diethyldithiocarbamate photometric method
ISO 3665:1996 Photography - Intra-oral dental radiographic film - Specification
ISO 3696 Water for analytical laboratory use - Specification and test methods
ISO 7491 Dental materials - Determination of colour stability
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1
mixing time
that part of the working time required in order to obtain a satisfactory mix of the components
3.2
working time
period of time, measured from the start of mixing, during which it is possible to manipulate a dental material without an adverse effect on its properties
3.3
net setting time
period of time, measured from the end of mixing, until the material has set according to the parameters and conditions specified in Annex A
Note: For the purposes of this part of YY 0271, in view of the wide variation in mixing times of cements, the net setting time is determined from the end of mixing.
4 Classification
4.1 Chemical type
The chemical composition and applications of dental cements are detailed in Annex A. For the purposes of this part, dental cements shall be classified on the basis of their chemical composition, as follows:
a) zinc phosphate cement, see A.1;
b) zinc polycarboxylate cement, see A.2;
c) glass polyalkenoate cement, see A.3.
Acid-base setting, water-based cements other than those listed above may fall within the scope of this part. If the manufacturer wishes to claim conformity for such a product, the type of material for which equivalence of properties is claimed shall be specified in accordance with 4.1 and 4.2 so that the correct performance limits are applied.
4.2 Application
For the purposes of this part, the application of water-based cements shall be classified as follows:
a) luting;
b) bases or lining;
c) restoration.
5 Material
5.1 General
The cement shall consist of a powder and liquid which, when mixed in accordance with the manufacturer’s instructions, shall conform to requirements in this clause and clause 8.
5.2 Components
5.2.1 Liquid
For non-encapsulated cements, visually inspect the liquid. It shall be free from deposits or filaments on the inside of its container. There shall be no visible signs of gelation.
5.2.2 Powder
For non-encapsulated cements, visually inspect the powder. It shall be free from extraneous material. If the powder is coloured, the pigment shall be uniformly dispersed throughout the powder.
5.3 Unset cement
The cement shall be mixed in accordance with clause 6, and then visually inspected. It shall be homogeneous and of a smooth consistency.
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 Classification
5 Material
6 Preparation of test specimens
7 Sampling
8 Requirements
9 Packaging, marking and information to be supplied by manufacturer
Annex A (Informative) Chemical composition and applications of dental cements
Annex B (Normative) Determination of net setting time
Annex C (Normative) Determination of film thickness (luting cements only)
Annex D (Normative) Determination of compressive strength
Annex E (Normative) Determination of acid erosion
Annex F (Informative) Determination of optical properties (optical properties) (glass polyalkenoate restorative cements only)
Annex G (Normative) Determination of optical properties (colour) (glass polyalkenoate restorative cements only)
Annex H (Normative) Determination of acid-soluble arsenic and lead contents
Annex I (Normative) Determination of radio-opacity
Bibliography
