Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1981 Evaluation of a fluorapatite-spinel ceramic as a bone implant Denginur Aksaci Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Materials Science and Engineering Commons Recommended Citation Aksaci, Denginur, "Evaluation of a fluorapatite-spinel ceramic as a bone implant " (1981). Retrospective Theses and Dissertations. 6961. https://lib.dr.iastate.edu/rtd/6961 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. 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In all cases we have filmed the best available copy. Universi^ Micfonlms International 300 N /EEB RD . ANN ARBOR, Ml 48106 8209092 Aknci, Denfinnr EVALUATION OF A FLUORAPATTTE-SPINEL CERAMIC AS A BONE IMPLANT Iowa State University PH.D. 1981 University Microfilms Intsrnâtionâl 300N.ZMbRa«l,AnnArbor.M14S106 PLEASE NOTE: In all cases this material has been filmed in the beet poeslble way from the available copy. Problems encountered wKh this document have been identified here with a check mark V 1. Glossy photographs or pages ^ 2. Colored illustrations, paper or print ^ 3. Photographs with dark background 4. Illustrations are poor copy 5. Pages with black marks, not original copy 6. Print shows through as there is text on both sides of page 7. Indistinct, broken or small print on several pages 8. Print exceeds margin requirements 9. Tightly bound copy with print lost in spine 10. Computer printout pages with indistinct print 11. 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For the Grwuate College Iowa State University Ames, Iowa 1981 11 TABLE OF CONTENTS Pag# ABSTRACT v INTRODUCTION 1 LITERATURE REVIEW 4 Ceramlos as Hard Tissue Implants A Aluminum oxide 4 Bloglass 6 Calolum phosphate salts 7 fluorapatlte and spinel 14 fraoture Meohanios 23 Brittle fracture and oraok propagation 23 Theoretical strength 23 Grlfflth-Orowan-Irwln analysis 26 Statistical nature of strength 30 Strength and fracture surface work 32 Static fatigue 36 Effects of microstructure 40 Bend test 42 EXPERIMENTAL PROCEDURE 48 Selection of the Composition 46 Specimen Preparation 52 Specimen preparation for x-ray diffraction 52 Ill Speolnen preparation for optical miorosoopy, bend teat and solubility test 52 X-Ray Siffraotoaeter Studies 33 Optical Microscope Studies on Pluorapat1te-Spinel Specimens 54 Study of the Bending Strength 55 Scanning Electron Microscope Studies 58 Solubility Studies 56 Soft Tissue Reaction lest 59 Implants 59 Microscopic Analysis of the Recovered Implant 66 RESULTS AND DISCUSSION 68a X-Ray Diffraction 68a Optical Microsoopy 68a Bending Strength 68a Scanning Electron Microscope Studies 80b Solubility Studies 93 Soft Tissue Reaction Test 99 Implants Xn-Vivo 102 Microscopic Analysis of the Implant- Tissue Sections 107 CONCLUSION 122 BIBLIOGRAPHY 123 iv Page ACKNOWLEDGIIENIS 128 APPEFDII A 129 Ringer's Solution 129 APFEirSlX B 130 Confidence Intervals for Means and the Student's t lest 130 APPENDIX C 132 Comparison of Means by the Student's t Test 132 V ABSTRACT The objective of this study waa to produoe a oeramlo that oan be used as a hard tissue Implant. After inves­ tigation of several mixtures of trioalolum phosphate, oalolum fluoride, magnesium carbonate and alumina, a composite of fluorapatlte and spinel was selected as the ceramic material. The ability to prepare sound samples and the minimum solubility In tissue fluids were the main reasons for the selection of a composite with one mole of fluorapatlte to three moles of magnesium alumlnate spinel. The ceramic was tested to determine the effect of porosity on strength so that the optimmm coalajLnation of microstructure and mechanical properties could be obtained. The effect of the duration of stay in the physlologloal environment on the bending strength was determined after in vitro tests in Ringer's solution for porous and non- porous bars, and also after in vivo tests of non-perous subcutaneous implants. Porous bone bridges Implanted in dogs were studied in terms of bone ingrowth, Implant stabilization and tissue compatibility. Thin sections of tte bone-oeramlo interface were prepared and analyzed using optical micros­ copy with polarized transmitted llgh*» vi The results of the tests in vivo and in vitro showed that the fluorapatite-spinel oeramio oan be suooessfuUy used as a permanent hard tissue implant. 1 INTRODUCTION Defects in bone, as a result of disease, trauma or congenital reasons, are a frequent occurrence. These are usually filled with bone graft which is, in most cases, autogenous bone, and sometimes homograft or heterograft bone. However, there are problems with all types of grafts. Homograft bone, while quite functional, is not always readily available. Autogenous bone is usually taken from the iliac crest, which involves another incision. Hetero- graft bone has been tried without conspicuous success. Therefore, a need for a synthetic material is obvious. The success of a biomaterial or implant is highly dependent on three major factors: the properties of the implant, the condition of the recipient, and the competency of the surgeon who implants and monitors progress of the implant. The properties required from an implant are: 1. Acceptance of the implant by the tissue 2. Non-toxic and non-carcinogenic 3. Chemically inert and stable (no time dependent degradation) 4. Adequate mechanical strength 5. Adequate fatigue life 6. Sound engineering design 7. Proper weight and density 2 8. Relatively inexpensive, reproducible, and easy to fabricate and process on a large scale. Generally, two classes of materials have been used to replace hard tissue: metals (1) and polymers (2). The metals are usually Vitallium and type 316, 3161 and 317 stainless steel, although the precious metals, tantalum and titanium are eJ-so sometimes use#. Advantages of metal implants are high-impact tensile strength, high resistance to wear, and ductile absorption of high strain energy. However, metals have some disadvantages like low biocompatibility, corrosion in physiological environment, mismatch of meoheuaical properties with tissues and too high density. The polymers used for tissue replace­ ment are usually polyethylene and polymethylmethacrylate cement. Although polymers are easy to fabricate and have low densities, their time-dependent degradation and low mechanical strengths are their major disadvantages. Both metals and polymers are walled off by the body with its foreign body response mechanism. This produces a fibrous capsule which may permit motion under stress. Excess movement causes inflammation, hard tissue resorption, euid failure. This need for other