1、Designation: F 451 08Standard 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 indica
2、tes the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers self-curing resins used prima-rily for the fixation of internal orthopedic prostheses. Themixture may be used in either the predough or d
3、ough 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 beincorporated, the composition of the set cement shall containpoly
4、(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 traditionally formulated and used has been reported in theliterature
5、 (1, 2).21.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 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 estab
6、lish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D 638 Test Method for Tensile Properties of PlasticsD 695 Test Method for Compressive Properties of RigidPlasticsD 3835 Test Method for Det
7、ermination of Properties ofPolymeric Materials by Means of a Capillary RheometerD 1193 Specification for Reagent WaterF 619 Practice for Extraction of Medical PlasticsF 748 Practice for Selecting Generic Biological Test Meth-ods for Materials and DevicesF 749 Practice for Evaluating Material Extract
8、s by Intracu-taneous Injection in the RabbitF 756 Practice for Assessment of Hemolytic Properties ofMaterialsF 763 Practice for Short-Term Screening of Implant Mate-rialsF 813 Practice for Direct Contact Cell Culture Evaluation ofMaterials for Medical DevicesF 895 Test Method for Agar Diffusion Cell
9、 Culture Screen-ing for CytotoxicityF 981 Practice for Assessment of Compatibility of Bioma-terials for Surgical Implants with Respect to Effect ofMaterials on Muscle and Bone2.2 ANSI/ADA Standard:No. 15 Specification for Acrylic Resin Teeth43. Terminology3.1 Definitions of Terms Specific to This St
10、andard: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).3.1.3 extrusionthe rate of flow of the materia
11、l 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 7.8.3).3.1.5 setting timethe time after commencement of mixingat which the temperature of the curing mass equals the averageof the maximum and ambient temperature
12、s (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:4.1.1 AppearanceThe liquid shall be free of extraneousparticulate matter or obvious visual contaminants in its con-tainer.1This specifica
13、tion is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.11 on Polymeric Materials.Current edition approved Aug. 1, 2008. Published September 2008. Originallyapproved in 1976. Last previous edition approved
14、in 2007 as F 451 99a(2007)1.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United St
16、ates.4.1.2 StabilityAfter being heated for 48 h at 60 6 2C, theviscosity 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 Powd
17、er:4.2.1 AppearanceThe powder shall be pourable and freeof extraneous materials, 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 p
18、redough stage, thematerial shall conform to the properties given in Table 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 co
19、mpliance with4.3.1 and 4.3.2.4.4 Cured PolymerThe material after setting 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 su
20、bsequently utilized in any of thenonsterile tests of this specification.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 t
21、othe powder at the discretion of the surgeon, the weight orvolume percent 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 spe
22、cification. Theunits shall be obtained from regular retail distribution 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
23、 be conducted under sterile conditions.7. Test Methods and Sample Size7.1 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 de
24、termining com-pliance to the requirements outlined in 4.1.1, 4.2.1, 8.1 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
25、 ViscosityRecord the viscositychange of two separate units (4.1.2) before 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,
26、 andta= flow time after heating exposure (4.1.2)of606 2Cfor 48 h in the 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 un
27、its shall be tested forsterility in accordance with the test methods described in U.S.Pharmacopoeia, “Sterility Tests” (3).7.5 Doughing Time:7.5.1 EnvironmentAll equipment, mixing surfaces, andmaterial (unit size) shall be maintained at 23 6 1C at least 2h prior to testing and tests shall be conduct
28、ed at 23 6 1C. Therelative humidity shall be 50 6 10 %.7.5.2 Mix all 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
29、-mately 1.5 min after the onset of mixing, gently probe themixture with 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
30、a cleanportion of the glove until the gloved finger separates cleanly.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
31、values found shall agree within 30 s of eachother, otherwise repeat 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 valuesof doughing times measur
32、ed shall not differ by more than 6112min from the average.7.5.6 Report the brand of non-powdered surgical glove usedfor dough time determinations. It is necessary that the type ofTABLE 1 Requirements for Powder Liquid MixturePropertyExtrusion,Viscosity TestsDough Usage,IntrusionTestsMax Dough Time,
33、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 70F451082glove be described in detail, including manufacturer, when thedough time is reported
34、.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 density polyethylene, or ultra-hig
35、h 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 press to produce the 6.0 mmspecim
36、en 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. 2. Report the maximumtemperatur
37、e 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 is greater than 5.0C, repeat th
38、e 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 TimeFrom the continuous time versus tem-perature recording of 7
39、.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 determinations of the setting time.
40、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 Heat MoldF4510837.7.3 The two v
41、alues 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 DeterminationThemanufacturer must specify whether
42、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/or 7.8.2) andTable 1. If the mixture i
43、s to be utilized in the dough stage, usethe intrusion test (7.8.3) and Table 1. If the mixture is to beused as a dual usage cement, then both the extrusion (7.8.1and/or 7.8.2) and intrusion (7.8.3) tests must be performed.7.8.1 Extrusion, Capillary Viscosity:7.8.1.1 Apparatus:7.8.1.1.1 Capillary Rhe
44、ometerAny capillary rheometer issatisfactory in which acrylic bone cement can be forced froma reservoir 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 ha
45、s been 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
46、 marks 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 le
47、ss than 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-da
48、rd viscosity 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 CorrectionsBone cement is a non-Newtonianfluid, t
49、he data may be reported as corrected data. For example,true shear rates, corrected for non-Newtonian flow behavior,and true shear stress, corrected for end effects or kinetic energylosses, may be calculated. In such cases, the exact details of themode of correction must be reported. Some correction factorswhich may apply are:(1) Piston friction,(2) Plunger back flow,(3) Cement compressibility,(4) Barrel back pressure,(5) Capillary entrance effects (Bagley correction) (6), and(6) Rabinowitsch shear rate correction (7).7.8.1.4 Procedure:(1
