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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN ISO 11244:2000 The
2、European Standard EN ISO 11244:1999 has the status of a British Standard ICS 11.060.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Dental brazing investments Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This Bri
3、tish Standard, having been prepared under the direction of the Health and Environment Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 February 2000 BSI 02-2000 ISBN 0 580 34013 9 BS EN ISO 11244:2000 Amendments issued since publication Amd.
4、No.DateComments National foreword This British Standard is the English language version of EN ISO 11244:1999. It is identical with ISO 11244:1998. The UK participation in its preparation was entrusted to Technical Committee CH/51, Prosthodontic materials, which has the responsibility to: aid enquire
5、rs to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations repr
6、esented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British S
7、tandards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to i
8、nclude all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, th
9、e EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii and iii, a blank page, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Wed No
10、v 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI A Reference
11、 number ISO 11244:1998(E) INTERNATIONAL STANDARD ISO 11244 First edition 1998-10-01 Dental brazing investments Revtements dentaires pour le brasage EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI )E(8991:44211 OSI Descripto
12、rs: dentistry, dental materials, dental brazing investments, classification, specifications, physical properties, tests, physical tests, marking, packaging, instructions. ii Contents 1 Scope1 2 Definitions 1 3 Classification1 4 Requirements.2 5 Sampling, test conditions and mixing.2 6 Test methods3
13、7 Manufacturers instructions .8 8 Packaging.8 9 Marking.8 Annex A (informative) Bibliography 10 EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI OSI)E(8991:44211 OSI iii Foreword ISO (the International Organization for Stand
14、ardization) 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
15、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. Draft Internatio
16、nal 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. International Standard ISO 11244 was prepared by Technical Committee ISO/TC 106, Dentistr
17、y, Subcommittee SC 2, Prosthodontic materials. Annex A of this International Standard is for information only. EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, We
18、d Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTERNATIONAL STANDARD ISOISO 11244:1998(E) 1 Dental brazing investments 1 Scope This International Standard establishes a classification of and specifies requirements for dental brazing investments. It specifies test methods to be used to
19、 determine compliance with these requirements. It lists information which shall be included in the manufacturers instructions and also gives requirements for labelling. 2 Definitions For the purposes of this International Standard, the following definitions apply. 2.1 brazing brazing process process
20、 of joining generally applied to metals in which, during or after heating, molten filler metal is drawn into or retained in the space between closely adjacent surfaces of the parts to be joined by capillary attraction NOTE In general the melting range of the filler metal is above 450 C, but always b
21、elow the melting temperature of the parent metal. 2.2 brazing investment blend of refractory fillers and binding system specially designed to allow the formation of a model on which dental restoration components are held in place while they are being joined by brazing 2.3 gypsum-bonded dental brazin
22、g investment refractory filler system and binding system consisting essentially of calcium sulfate hemihydrate, specially designed for use when brazing dental alloy restorations 2.4 phosphate-bonded dental brazing investment refractory filler system and binding system consisting essentially of an ac
23、idic phosphate (such as monoammonium phosphate) and a basic oxide (such as magnesium oxide) specially designed for use when brazing dental alloy restorations 2.5 special liquid liquid, consisting mainly of a suspension of colloidal silica particles in water, made available by the manufacturer or sup
24、plier for mixing with the brazing investment powder for the purpose of increasing thermal expansion 3 Classification Dental brazing investments are classified into two types according to their composition. Type 1:Gypsum-bonded dental brazing investments. Type 2:Phosphate-bonded dental brazing invest
25、ments. EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI )E(8991:44211 OSI OSI 2 Unless the manufacturer states otherwise, Type 1 shall be used with brazing alloys having brazing temperatures below 1000 C and Type 2 with thos
26、e having brazing temperatures above 1000 C. 4 Requirements 4.1 Quality The powder shall be a uniform and dry mixture, free from foreign matter and lumps. Test in accordance with 6.1. 4.2 Fluidity The average diameter of the base of the set investment shall be not more than 100 mm. Test in accordance
27、 with 6.2. 4.3 Setting time The setting time shall not differ by more than 30 % from the setting time stated by the manufacturer. If the manufacturer gives a range of setting time, then the measured setting time shall not differ from the midpoint of this range by more than 30 %. Test in accordance w
28、ith 6.3. 4.4 Compressive strength The compressive strength shall fall within the range of 2,0 MPa to 10,0 MPa. Test in accordance with 6.4. 4.5 Linear thermal expansion The linear thermal expansion shall not differ by more than 15 % from the value stated by the manufacturer. If the manufacturer give
29、s a range of linear thermal expansion, then the linear thermal expansion shall not differ from the midpoint of this range by more than 15 %. Test in accordance with 6.5. 4.6 Linear setting expansion For Type 1 materials, the linear setting expansion shall be within 15 % of the value stated by the ma
30、nufacturer. If the manufacturer gives a range of linear setting expansion, then the linear setting expansion shall not differ from the midpoint of this range by more than 15 %. Test in accordance with 6.6. 5 Sampling, test conditions and mixing 5.1 Sampling Sufficient retail packages of the material
31、 of one lot shall be obtained to provide at least 5 kg of material. Any packages that are not sealed shall be discarded. When the powder is supplied in bulk, it shall be thoroughly blended and stored in a moisture-proof container. All specimens shall be prepared using the same lot of powder. 5.2 Tes
32、t conditions All mixing and testing shall be carried out at (23 2) C and (50 10) % relative humidity in a room shielded from obvious drafts. Prior to mixing, all test materials shall be stored for at least 16 h under these conditions. All equipment shall be clean and at the test temperature. The bow
33、ls used for mixing shall be moistened and then shaken free of any excess water before being used. All other equipment shall be dry. EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI OSI)E(8991:44211 OSI 3 5.3 Mixing 5.3.1 App
34、aratus It is recommended that separate sets of mixing bowls, tools and material contacting parts be used for Type 1 and Type 2 dental brazing investments. If the manufacturer recommends an apparatus for mechanical mixing, it shall be used. 5.3.2 Procedure Measure to an accuracy of 1 % the required a
35、mount of powder and the required volume of water or special liquid in the mixture ratio recommended by the manufacturer. The water should meet the requirements of ISO 3696 (grade 3). If the manufacturer specifies a range of volumes, use the mid-point value. Pour the water or special liquid into the
36、mixing bowl and sift the investment powder into the water or liquid within 10 s, minimizing entrapment of air. Begin timing from the moment the investment powder and the water or liquid first make contact. Hand spatulate with a speed of approximately two turns per second for 15 s. Mechanically mix a
37、ccording to the manufacturers recommended mixing procedure item 7 d) for the time specified by the manufacturer and then transfer the mixed investment to the test moulds or form within 15 s. 6 Test methods 6.1 Visual inspection The material shall be examined by eyesight with normal acuity and shall
38、meet the quality requirement in 4.1. 6.2 Fluidity 6.2.1 Apparatus 6.2.1.1 Clean, dry cylindrical mould, having a length of (50 1) mm and an inside diameter of (35 1) mm constructed from a corrosion-resistant, non-absorbent material. 6.2.1.2 Flat, square glass plate of dimensions at least 150 mm 3 15
39、0 mm. 6.2.1.3 Dental vibrator operating on 50 Hz or 60 Hz power supply. 6.2.1.4 Measuring scale, graduated in millimetres. 6.2.1.5 Mould release agent, such as silicone spray or silicone grease. 6.2.2 Procedure Coat the inside surface of the mould with mould release agent. Mix the investment as desc
40、ribed in 5.3 using 200 g of powder and the recommended amount of liquid. Centre the mould base on the glass plate and place it on the dental vibrator platform. Vibrate the investment mix into the mould until it is slightly overfilled. Do not vibrate for more than 20 s. Level the mix flush with the t
41、op of the mould. At 20 s after the end of mixing, lift the mould from the plate vertically at a rate of approximately 10 mm/s, allowing the mix to slump on the plate. As soon as the mixed investment has set, measure with the scale the largest and smallest horizontal dimensions of the base of the set
42、 investment, and report the average value. 6.2.3 Evaluation Make two such tests as described in 6.2.2. If the results of both tests meet the requirement (4.2), the product complies with this requirement of this International Standard. If neither meets the requirement, then the product fails to compl
43、y. If one test result meets the requirement and one fails the requirement, then the test shall be repeated three more times. If all three test results meet the requirement (4.2), then the product complies with this requirement of this International Standard. Otherwise it fails to comply. EN ISO 1124
44、4:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI )E(8991:44211 OSI OSI 4 6.3 Setting time 6.3.1 Apparatus 6.3.1.1 Needle apparatus, as shown in figure 1, meeting the following requirements. a) Total mass of the rod and needle (A, B and
45、 C in figure 1) shall be (300 1) g. b) Scale (D), graduated in millimetres. c) Baseplate (H) of plate glass, measuring about 100 mm 3 100 mm. d) Vicat needle (C) of circular cross-section and with a diameter of (1,00 0,05) mm and a flat end. Key A Additional weightE Lock screw B RodF Support bracket
46、 C Vicat needleG Conical ring mould D Graduated scaleH Baseplate Figure 1 Apparatus for Vicat needle (see 6.3.1.1) EN ISO 11244:1999 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 15 13:09:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI OSI)E(8991:44211 OSI 5 6.3.1.2 Clean, dry conical mould, con
47、structed from a corrosion-resistant, non-absorbent material, having an inside diameter 70 mm at the top and 60 mm at the base and a height of 40 mm. 6.3.1.3 Mould release agent, such as silicone spray or silicone grease. 6.3.2 Procedure Adjust the scale of the needle apparatus to read zero (0) when
48、the needle is in contact with the baseplate. Make an investment mix in accordance with 5.3, using 300 g of investment powder and the recommended amount of liquid. Overfill the ring mould with the mix and then level the surface. When the glossy surface of the mix has completely disappeared, lower the
49、 needle until it touches the surface and then release it gently, allowing it to sink into the mix under its own mass. Repeat this procedure at 15-s intervals, wiping the needle clean after each penetration and moving the sample at least 5 mm so that the needle does not enter the same place twice. Avoid making any penetration of the needle closer than 5 mm to the mould walls. Record the setting time as the time from beginning mixing until the needle first fails to penetrate to within 5 mm of the mould bottom. 6.3.3 Evaluatio
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