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Correlation between structural          properties and in vivo            biocompatibility of      alumina/zirconia biocer...
Motivation There is a continuous input from bioengineering for  reaching a high level of comfort, improving reliability, ...
Motivation     Al2O3                               ZrO2 Excellent hardness and        Was introduced to overcome  wear p...
The ideal ceramic is a high performance biocomposite that combinesthe excellent material properties of alumina in terms of...
Goal An evaluation of the structural and  biocompatibility properties of a new  zirconia toughened alumina ceramics. The...
Methods   Investigation of the structural changes induced by TiO2    addition to Al2O3/ ZrO2 are made by FTIR spectroscop...
Results: XRD Spectroscopy                                                                 XRD patterns of (a) 90Al2O3∙10Zr...
FTIR Spectroscopy: (a) 90Al2O3∙10ZrO2 and                         (b) 90Al2O3∙10ZrO2 + 5%TiO2 samples.                    ...
SEM: Irregular shape of 90%Al2O3-10%ZrO2(a)     and 90%Al2O3-10%ZrO2+5%TiO2 (b) granules and     their corresponding micro...
Biocompatibility evaluation: Animal model   (Wistar rats) Surgical procedure
Surgical procedure: filling the critical size      defect created in the femurCollagen film
Monitoring the osseointegration process at   different time intervals (3, 6 weeks).   Radiographic images90Al2O3∙10ZrO290A...
SEM images of the sheared implant surfaces:                                       3 weeks  90Al2O3∙10ZrO290Al2O3∙10ZrO2 + ...
SEM images of the sheared implant surfaces:                                    6 weeks  90Al2O3∙10ZrO290Al2O3∙10ZrO2 + 5%T...
Haversian canal details
SEM Analysis reveals: Fibrinous and collagenous matrix extensively interdigitated  with the three-dimensional interconnec...
XRD spectrum of the femoral bone                 900                 800                 Z                                ...
Histological images: The connective tissue     was also examined to detect any     immunological or inflammatory responses...
Conclusions Structural investigations of the proposed composites  using XRD and FTIR spectroscopy confirms the  stability...
The team: Prof. dr. Gultekin Goller and dr. Ipek Akin, Istanbul  Technical University, Materials Science Department. Pro...
Jerry and Jimmy                  LindaThank you
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SIMONA CAVALU_Correlation between structural properties and in vivo biocompatibility of alumina/zirconia bioceramics

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Correlation between structural properties and in vivo biocompatibility of alumina/zirconia bioceramics

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SIMONA CAVALU_Correlation between structural properties and in vivo biocompatibility of alumina/zirconia bioceramics

  1. 1. Correlation between structural properties and in vivo biocompatibility of alumina/zirconia bioceramics Simona Cavalu Professor Preclinical Sciences DepartmentFaculty of Medicine and Pharmaceutics University of Oradea ROMANIA
  2. 2. Motivation There is a continuous input from bioengineering for reaching a high level of comfort, improving reliability, finding new applications. This development is also a response to the growing number of patients afflicted with traumatic or non- traumatic conditions: the number of implants is continuously growing, due to the increase in persons suffering of arthritis and joint problems. As the average age of population grows, the need for medical devices to replace damaged or worn tissues increases. As patients have become more and more demanding regarding esthetic and biocompatibility aspects of their dental restorations
  3. 3. Motivation Al2O3 ZrO2 Excellent hardness and  Was introduced to overcome wear properties. the limitations of alumina. Fracture toughness values  When properly manufactured, are lower than those of zirconia has a higher strength, the metals used in but only 50% of alumina’s orthopedic surgery. hardness. Chemical and  Unstable material. The hydrothermal stability. tetragonal phase tends to It is a brittle material, transform into the monoclinic phase. The addition of with low resistance to the stabilizing materials propagation of cracks. (Y2O3)during manufacture, can control the phase transformation of zirconia. Al2O3, ZrO2, TiO2 have been considered as bioinert ceramics since they cannot induce apatite formation in SBF. They do however support bone cell attachment, proliferation and differentiation.
  4. 4. The ideal ceramic is a high performance biocomposite that combinesthe excellent material properties of alumina in terms of chemicalstability and low wear and of zirconia with its superior mechanicalstrength and fracture toughness. Alumina/zirconia ceramics were successfully used in total hip/knee arthroplasty in the last decades. For dental application: root canal posts, orthodontic brackets, implant abutments and all- ceramic restaurations.
  5. 5. Goal An evaluation of the structural and biocompatibility properties of a new zirconia toughened alumina ceramics. The composition of proposed materials for this study: 90%Al2O3-10%ZrO2 and 90%Al2O3-10%ZrO2+5%TiO2 prepared by using modern processing technologies – spark plasma sintering.
  6. 6. Methods Investigation of the structural changes induced by TiO2 addition to Al2O3/ ZrO2 are made by FTIR spectroscopy and X- ray diffraction (XRD) analysis . Scanning Electron Microscopy (SEM) and EDX are used for microstructure and morphology investigation of the samples. In order to perform in vivo tests, the rat model has been applied for biocompatibility evaluation. The rat model has been accepted as a model for the effects of systemic disease on osseointegration. SEM micrographs are recorded on the rats femur along with the elemental composition of the sheared implant surfaces at different time intervals after the surgery. Histological examination of the connective tissue is performed to detect any immunological or inflammatory responses.
  7. 7. Results: XRD Spectroscopy XRD patterns of (a) 90Al2O3∙10ZrO2 and (b) 90Al2O3∙10ZrO2 + 5%TiO2 samples. 1200 Z A  The TiO2 addition slightly A Z modifies the relative intensities 1000 of XRD peaks. Both samples A A show similar peak positions, 800 A Z A A the slight change of relative Z A A intensities of XRD peaks could be attributed T to weakIntensity (a.u.) Z A 600 Z A A Z (a) differences in size and shape of the crystals in these samples 400 A A A A A  This result suggest that 200 Z A zirconia present in the T Z A composite is, therefore, 0 A (b) retained in the tetragonal form as alumina particles prevent 0 10 20 30 40 50 60 70 80 90 100 the tetragonal to monoclinic 2 theta (degrees) transformation by matrix constraint.
  8. 8. FTIR Spectroscopy: (a) 90Al2O3∙10ZrO2 and (b) 90Al2O3∙10ZrO2 + 5%TiO2 samples.  The large bands around 1088 cm-1 are assigned to stretching vibration of Al–O–Al bonds.  The Al-O stretching vibrations of 465 0.6 1088 tetrahedral AlO4 groups are 614 660 related with the bands in the 780 1168 region 900 – 750 cm-1 and 564 518 797 0.5 bands in 650 – 460 cm-1 regionIntensity (a.u.) (a) are associated with stretching modes of AlO6 octahedra. 0.4  The absorption bands at 518 to 564 cm-1 correspond to Zr-O vibrations in tetragonal ZrO2 0.3 phase. (b)  Upon TiO2 addition to alumina- zirconia matrix, the relative 0.2 intensity of 660/614 cm-1 band 1200 1000 800 Wavenumber (cm ) -1 600 400 is considerably modified, as a superposition of the characteristics absorption bands occurs in this region.
  9. 9. SEM: Irregular shape of 90%Al2O3-10%ZrO2(a) and 90%Al2O3-10%ZrO2+5%TiO2 (b) granules and their corresponding microstructure (c, d)a) c)b) d)
  10. 10. Biocompatibility evaluation: Animal model (Wistar rats) Surgical procedure
  11. 11. Surgical procedure: filling the critical size defect created in the femurCollagen film
  12. 12. Monitoring the osseointegration process at different time intervals (3, 6 weeks). Radiographic images90Al2O3∙10ZrO290Al2O3∙10ZrO2 + 5%TiO2
  13. 13. SEM images of the sheared implant surfaces: 3 weeks 90Al2O3∙10ZrO290Al2O3∙10ZrO2 + 5%TiO2
  14. 14. SEM images of the sheared implant surfaces: 6 weeks 90Al2O3∙10ZrO290Al2O3∙10ZrO2 + 5%TiO2
  15. 15. Haversian canal details
  16. 16. SEM Analysis reveals: Fibrinous and collagenous matrix extensively interdigitated with the three-dimensional interconnected porous structure after first 3 weeks. Distinct gaps between the implant and the bone were observed in a few locations. After 6 weeks, the matrix around the surface implanted area appeared more densely, well covered and extensively integrated into a mixture of mineralized tissue, osteoid and dense matrix. As revealed from the EDAX spectra, calcium/phosphate ratio is an indicative of the surface implant coverage for a successful osseointegration, varying from 1.5 (after 3 weeks) to 1.9 (after 6 weeks). The results suggest that TiO2 presence in the samples favor the osseointegration process.
  17. 17. XRD spectrum of the femoral bone 900 800 Z AlZr Biocomposite 700 A A Z Z A A A A A A T Z 600 500 Z Bone/AlZr I (a.u.) B Z Z A A A 400 A B A AZ 300 * 200 * Bone 100 0 0 20 40 60 80 100 2Θ (deg)
  18. 18. Histological images: The connective tissue was also examined to detect any immunological or inflammatory responses osteoblastsA network of woven bony trabecular architecture with cellular infiltrationwas observed
  19. 19. Conclusions Structural investigations of the proposed composites using XRD and FTIR spectroscopy confirms the stability of the microstructure upon TiO 2 addition to alumina/zirconia matrix. In vivo: both implanted materials in critical size defect of the femur were well integrated in the original bone defects and covered with a layer of soft tissue at 6 weeks after implantation, as demonstrated by SEM images. As revealed from the EDAX spectra, Ca/P ratio is an indicative of the surface implant coverage for a successful osseointegration, varying from 1.5 (after 3 weeks) to 1.9 (after 6 weeks). No signs of inflammatory reactions, such as necrosis or reddening suggesting implant rejection, were found upon histological examination.
  20. 20. The team: Prof. dr. Gultekin Goller and dr. Ipek Akin, Istanbul Technical University, Materials Science Department. Prof. dr. Viorica Simon and dr. Oana Ponta Babes-Bolyai University, Faculty of Physics & Institute of Interdisciplinary Research in Bio-Nano-Sciences, Cluj-Napoca, Romania. Assoc. prof. Cristian Ratiu and dr. Ioan Oswald University of Oradea, Faculty of Medicine and Pharmaceutics, Oradea, Romania. Romania-Turkey Bilateral Cooperation project 385/2010.
  21. 21. Jerry and Jimmy LindaThank you

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