1、Designation: F 451 99ae1Standard Specification forAcrylic Bone Cement1This standard is issued under the fixed designation F 451; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses ind
2、icates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEFigure 1 was editorially corrected in June 2003.1. Scope1.1 This specification covers self-curing resins used prima-rily for the fixation of internal orthopedic pros
3、theses. Themixture may be used in either the predough or dough stage inaccordance with the manufacturers recommendations.1.2 Units of premeasured powder and liquid are supplied ina form suitable for mixing. The mixture then sets in place.1.3 While a variety of copolymers and comonomers may beincorpo
4、rated, the composition of the set cement shall containpoly(methacrylic acid esters) as its main ingredient.1.4 This specification covers compositional, physical per-formance, and biocompatibility as well as packaging require-ments. The biocompatibility of acrylic bone cement as it hasbeen traditiona
5、lly formulated and used has been reported in theliterature (1, 2).21.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the ap
6、plica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 695 Test Method for Compressive Properties of RigidPlastics3D 3835 Test Method for Determination of Properties ofPolymeric Materials by Means of a Capillary Rheometer4E 29 Practice for Using Significant D
7、igits in Test Data toDetermine Conformance With Specifications5E 141 Practice for Acceptance of Evidence Based on theResults of Probability Sampling5F 619 Practice for Extraction of Medical Plastics6F 748 Practice for Selecting Generic Biological Test Meth-ods for Materials and Devices6F 749 Practic
8、e for Evaluating Material Extracts by Intracu-taneous Injection in the Rabbit6F 756 Practice for Assessment of Hemolytic Properties ofMaterials6F 763 Practice for Short-Term Screening of Implant Mate-rials6F 813 Practice for Direct Contact Cell Culture Evaluation ofMaterials for Medical Devices6F 89
9、5 Practice for Agar Diffusion Cell Culture Screeningfor Cytotoxicity6F 981 Practice for Assessment of Compatibility of Bioma-terials (Nonporous) for Surgical Implants with Respect toEffect of Materials on Muscle and Bone62.2 ANSI/ADA Standard:No. 15 Specification for Acrylic Resin Teeth73. Terminolo
10、gy3.1 Definitions of Terms Specific to This Standard:3.1.1 doughing timethe time after commencement ofmixing at which the mixture ceases to adhere to a standardprobe (see 7.5).3.1.2 exothermic or maximum temperaturethe maximumtemperature of the mixture due to self-curing in a standardmold (see 7.6).
11、3.1.3 extrusionthe rate of flow of the material through astandard orifice under load (see 7.8.1).3.1.4 intrusionthe distance of flow of the mixture into astandard mold under load (see 7.8.2).3.1.5 setting timethe time after commencement of mixingat which the temperature of the curing mass equals the
12、 averageof the maximum and ambient temperatures (see 7.7).3.1.6 unitone package or vial of premeasured powdercomponent and one package or vial of premeasured liquidcomponent.4. Physical Requirements4.1 Liquid:1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical
13、Materials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current edition approved May 10, 1999. Published July 1999. Originallypublished as F 451 76. Last previous edition F 451 95.2The boldface numbers in parentheses refer to the list of references at the
14、end ofthis standard.3Annual Book of ASTM Standards, Vol 08.01.4Annual Book of ASTM Standards, Vol 08.02.5Annual Book of ASTM Standards, Vol 14.02.6Annual Book of ASTM Standards, Vol 13.01.7Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copy
15、right ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.1 AppearanceThe liquid shall be free of extraneousparticulate matter or obvious visual contaminants in its con-tainer.4.1.2 StabilityAfter being heated for 48 h at 60 6 2C, theviscosity
16、of the liquid shall not increase by more than 10 % ofits original value (see 7.3).4.1.3 SterilityThe liquid, as poured from its container,shall pass the tests described in “Sterility TestsLiquid andOintments” (7.4) (3).4.2 Powder:4.2.1 AppearanceThe powder shall be pourable and freeof extraneous mat
17、erials, such as dirt or lint (7.2.2).4.2.2 SterilityThe powder, as poured from its package,shall pass the tests described in “Sterility TestsSolids” (7.4)(2).4.3 Powder-Liquid Mixture:4.3.1 If the mixture is to be used in its predough stage, thematerial shall conform to the properties given in Table
18、 1.4.3.2 If the mixture is to be used in its dough stage, thematerial shall conform to the properties given in Table 1.4.3.3 If the mixture can be used in either its predough ordough stages, separate units must be tested for compliance with4.3.1 and 4.3.2.4.4 Cured Polymer The material after setting
19、 shall con-form to the properties given in Table 2.5. Weights and Permissible Variations5.1 Weight and volume measurements shall be made on therespective powder and liquid components of five units (see3.1). These units may be subsequently utilized in any of thenonsterile tests of this specification.
20、5.2 The weights, or volume of the powder and liquidcomponents, or both, shall not deviate by more than 5 % fromthose stated on the package (9.2.2), of each of five units.5.3 Where a radiopaque material is supplied for addition tothe powder at the discretion of the surgeon, the weight orvolume percen
21、t of the radiopaque material shall not deviate bymore than 15 % from the value stated on the package (9.2.3).6. Sampling6.1 Units of powder and liquid shall be procured to providesufficient material for all the tests of this specification. Theunits shall be obtained from regular retail distribution
22、channels.Provided no repeat tests are required, this will amount tobetween seven and ten units.6.2 It will only be necessary to maintain sterility in testsdescribed in 7.4. All other tests described in this specificationneed not be conducted under sterile conditions.7. Test Methods and Sample Size7.
23、1 Maintain all equipment, mixing surfaces, and materialsat 23 6 2C at least 2 h prior to testing and conduct all tests at23 6 2C and 50 6 10 % relative humidity unless otherwisespecified.7.2 InspectionUse visual inspection in determining com-pliance to the requirements outlined in 4.1.1, 4.2.1, 8.1
24、and 8.2.7.2.1 The liquid component of two separate units shallcomply with the requirements of 4.1.1 and 8.1.7.2.2 The powder component of two separate units shallcomply with the requirements of 4.2.1 and 8.1.7.3 Liquid Component ViscosityRecord the viscositychange of two separate units (4.1.2) befor
25、e and after theheating exposure by timing the flow of the liquid level betweenthe 0 and 5 mL marks of a 10 mL measuring pipet. Calculatethe percent change as follows:% Change 5ta2 tbtb3 100 (1)where:tb= flow time before heating, andta= flow time after heating exposure (4.1.2) of 60 6 2Cfor 48 h in t
26、he dark in a closed container.7.3.1 An alternative method for viscosity may be used if itcan be demonstrated to yield similar results. Both shall complyto the less than 10 % change specified (4.1.2).7.4 The components of the two units shall be tested forsterility in accordance with the test methods
27、described in U.S.Pharmacopoeia,“ Sterility Tests” (3).7.5 Doughing Time:7.5.1 Environment All equipment, mixing surfaces, andmaterial (unit size) shall be maintained at 23 6 1C at least 2h prior to testing and tests shall be conducted at 23 6 1C. Therelative humidity shall be 50 6 10 %.7.5.2 Mix all
28、 the powder and liquid of a single unit togetheras directed by the manufacturers instructions (see 8.2). Start astop watch at the onset of combining the liquid to the powderand read all subsequent times from this stop watch. Approxi-mately 1.5 min after the onset of mixing, gently probe themixture w
29、ith a non-powdered surgically gloved (latex) finger.Take visual notice as to the formation of fibers between thesurface of the mix and the finger as it leaves the surface. Repeatthis process from that time on at 15 s intervals with a cleanportion of the glove until the gloved finger separates cleanl
30、y.Denote the time at which this is first observed as the doughingtime. Mix the mixture between determinations to expose freshmaterial for each probing.7.5.3 Determine the average doughing time from two sepa-rate units.7.5.4 The two values found shall agree within 30 s of eachother, otherwise repeat
31、the test on two additional units. Reportthe average of all four tests and the range of values.7.5.5 Report the doughing time to the nearest 15 s as theaverage of all determinations. Maximum and minimum valuesTABLE 1 Requirements for Powder Liquid MixturePropertyExtrusion,Viscosity TestsDough Usage,I
32、ntrusionTestsMax Dough Time, min. 5.0 5.0Setting Time Range, min. 5 to 15 5 to 15Temperature, max., C 90 90Intrusion, min., mm . 2.0TABLE 2 Requirements for Cured Polymer After SettingProperty RequirementCompressive Strength, min., MPa 70F 451 99ae12of doughing times measured shall not differ by mor
33、e than 6112min from the average.7.6 Exothermic TemperatureWithin 1 min after doughingtime, gently pack approximately 25 g of the dough described in7.5 into the mold described in Fig. 1. This mold shall be madeof polytetrafluoroethylene (PTFE), poly(ethyleneterephtha-late), polyoxymethylene, high den
34、sity polyethylene, or ultra-high molecular weight polyethylene (UHMWPE) and beequipped with a No. 24 gage wire thermocouple, or similardevice, positioned with its junction in the center of the mold ata height of 3.0 mm in the internal cavity. Immediately seat theplunger with a C-clamp or suitable pr
35、ess to produce the 6.0 mmspecimen height. Upon producing plunger seating, remove theexcess material and the C-clamp or press for the remainder ofthe procedure. Continuously record the temperature with re-spect to time from the onset of mixing the liquid and thepowder until cooling is observed, Fig.
36、2. Report the maximumtemperature recorded to the nearest 1C. This should notexceed the value given in Table 1.7.6.1 The maximum temperature shall be the average of twoseparate determinations reported to the nearest 1C.7.6.2 If the difference between the maximum temperaturefor the two determinations
37、is greater than 5.0C, repeat the teston two additional units and report the average of all four runsto the nearest 1C. Individual maximum and minimum valuesfor maximum temperature shall not differ by more than 64Cof the average value of all determinations.7.7 Setting Time From the continuous time ve
38、rsus tem-perature recording of 7.6, the setting time (Tset) is the timewhen the temperature of the polymerizing mass is as follows:Tmax1 Tamb!/2 (2)where:Tmax= maximum temperature, C, andTamb= ambient temperature of 23 6 1C.7.7.1 Report the setting time to the nearest 5 s.7.7.2 Make two separate det
39、erminations of the setting time.NOTE 1Dimensions in millimetres and 60.2 unless otherwise specified. Material for all components: Polytetrafluoroethylene, poly(ethylenetereph-thalate), polyoxymethylene, high density polyethylene, or ultra-high molecular weight polyethylene (UHMWPE).FIG. 1 Exothermic
40、 Heat MoldF 451 99ae137.7.3 The two values should agree within 1 min of eachother, otherwise repeat the test on two additional units andreport the average of all runs.7.7.4 Report the setting time to the nearest 15 s as theaverage of all determinations.7.8 Flow Properties and Viscosity Determination
41、Themanufacturer must specify whether the cement may be used inits pre-dough or dough state, or both. The determination of itsusage dictates which of the following tests the cement shouldcomply with. If the mixture is to be utilized in the pre-doughstage, use the extrusion, viscosity test (7.8.1) and
42、 Table 1. If themixture is to be utilized in the dough stage, use the intrusiontest (7.8.2) and Table 1. If the mixture is to be used as a dualusage cement, then both the extrusion (7.8.1) and intrusion(7.8.2) tests must be performed.7.8.1 Extrusion, Viscosity:7.8.1.1 Apparatus:7.8.1.1.1 RheometerAn
43、y capillary rheometer is satisfac-tory in which acrylic bone cement can be forced from areservoir through a capillary die and in which temperature,applied force, output rate, and barrel and die dimensions can becontrolled and measured accurately. Equipment that provides aconstant shear rate has been
44、 shown to be equally useful. Thecapillary die of the rheometer shall have a smooth straight borethat is held within 60.0076 mm (60.0003 in.) in diameter andshall be held to within 60.025 mm (60.001 in.) in length. Thebore and its finish are critical. It shall have no visible drill orother tool marks
45、 and no detectable eccentricity.7.8.1.1.2 Due to the extreme sensitivity of flow data to thecapillary dimensions, it is important that the capillary dimen-sions are measured with precision and reported. The length todiameter ratio shall normally be between 20 and 40. Largerratios and ratios less tha
46、n that suggested require applying largecorrections to the data (4, 5). In addition, the ratio of thereservoir diameter to capillary diameter should be between 3and 15. See Test Method D 3835 for further details of capillaryrheometers.7.8.1.2 CalibrationPerform the test with a certified stan-dard vis
47、cosity fluid approximating that expected for bonecement (50 Ns/m2to 500 Ns/m2). Determine the viscosity ofthe standard fluid and the percent error from its specified value.Report this error along with the viscosity of the tested cements.7.8.1.3 Corrections Since bone cement is a non-Newtonian fluid,
48、 the data may be reported as corrected data.For example, true shear rates, corrected for non-Newtonianflow behavior and true shear stress corrected for end effects orkinetic energy losses, may be calculated. In such cases, theexact details of the mode of correction must be reported. Somecorrection f
49、actors which may apply are:(a) (a) Piston friction,(b) (b) Plunger back flow,(c) (c) Cement compressibility,(d) (d) Barrel back pressure,(e) (e) Capillary entrance effects (Bagley correction) (6),(f) (f) Rabinowitsch shear rate correction (7).7.8.2 Procedure:7.8.2.1 Select conditions of temperature and shear stress orshear rate in accordance with expected usage so that the flowrate will fall within desired limits.7.8.2.2 Inspect the rheometer and clean it if necessary.Ensure that previous cleaning procedures and usage have notchanged the
