Different sized silver nanoparticles were sputtered onto tantalum oxide with micro and nanopores. These samples were produced in order to achieve nanostructured samples with antibacterial activity suitable for a biomaterial. The porous tantalum oxide nanostructures were created by performing PEO to high-purity tantalum sheets. Afterwards, silver nanoparticles with 1nm and 2nm were deposited onto the manufactured substrates through magnetron sputtering. Then, some of these samples were covered by a thin carbon layer, using the same method. The samples were then submitted to characterization techniques in order to evaluate their physical, chemical, functional and mechanical properties.
Morphologically, every sample presented micro and nanopores which means the PEO technique was successful. It is also possible to observe silver nanoparticles on the surface of the sputtered substrates. The topography results confirmed the fact that the PEO technique created porosity since the mean roughness of the treated samples is higher than the pure Ta sheets. The chemical composition of the samples reported an incorporation of bioactive elements such as Ca and P during the PEO treatment. Furthermore, it confirmed the presence of silver and carbon on the substrates when they were deposited.
The ICP-OES results regarding the silver ion release showed that the samples that were covered with carbon exhibited higher ionization rates since silver and carbon form a nano-galvanic couple which promotes the galvanic corrosion of silver. However, even with the higher ionization rates, the ICP-OES cumulative results of ionization show very minimal silver release, which means that the quantity of silver NPs sputtered onto the substrate was not sufficient to produce antibacterial activity. Halo tests confirmed the suspicion that there was no antibacterial activity on the samples.
Mechanical characterization techniques revealed that the coating showed good adhesion to the surface. Additionally, it appears that the carbon layer has the ability of improving the mechanical robustness of the samples and in some cases preventing the removal of nanoparticles. However, it is important to mention that the robustness of the samples is a parameter that requires further investigation in order to achieve a dental implant with the mechanical robustness to withstand surgery procedure.
CONCLUSIONS AND FUTURE WORK
Pedro Agostinho 53
In future works, the deposition of more/bigger silver nanoparticles, while avoiding the formation of a film layer, can be an interesting starting point.
Furthermore, in order to create a functioning prototype, it will be crucial to test several carbon layers with different thicknesses to increase the mechanical robustness while further promoting the release of silver ions through nano-galvanic corrosion.
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BIBLIOGRAPHY
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BIBLIOGRAPHY
1. Hildebrand C, Fried K, Tuisku F, Johansson CS. Teeth and tooth nerves. Prog Neurobiol. 1995;45(3):165-222. doi:10.1016/0301-0082(94)00045-J
2. Agulyansky A. INTRODUCTION. In: Chemistry of Tantalum and Niobium
Fluoride Compounds. Elsevier; 2004:1-10. doi:10.1016/b978-044451604-6/50001-x 3. Yang Z, Xi Y, Bai J, et al. Covalent grafting of hyperbranched poly-L-lysine on
Ti-based implants achieves dual functions of antibacteria and promoted osteointegration in vivo. Biomaterials. 2021;269:120534.
doi:10.1016/j.biomaterials.2020.120534
4. Zafar MS, Najeeb S, Khurshid Z. Introduction to dental implants materials, coatings, and surface modifications. In: Dental Implants. Elsevier; 2020:1-4.
doi:10.1016/b978-0-12-819586-4.00001-9
5. Guo T, Gulati K, Arora H, Han P, Fournier B, Ivanovski S. Race to invade:
Understanding soft tissue integration at the transmucosal region of titanium dental implants. Dent Mater. Published online March 4, 2021.
doi:10.1016/j.dental.2021.02.005
6. Sakka S, Baroudi K, Nassani MZ. Factors associated with early and late failure of dental implants. J Investig Clin Dent. 2012;3(4):258-261. doi:10.1111/j.2041-1626.2012.00162.x
7. Tanner A, Maiden MFJ, Lee K, Shulman LB, Weber HP. Dental Implant Infections.
Clin Infect Dis. 1997;25(s2):S213-S217. doi:10.1086/516243
8. Liaw K, Delfini RH, Abrahams JJ. Dental Implant Complications. Semin Ultrasound, CT MRI. 2015;36(5):427-433.
doi:https://doi.org/10.1053/j.sult.2015.09.007
9. Zhao Y, Pu R, Qian Y, Shi J, Si M. Antimicrobial photodynamic therapy versus antibiotics as an adjunct in the treatment of periodontitis and peri-implantitis: A systematic review and meta-analysis. Photodiagnosis Photodyn Ther.
2021;34:102231. doi:10.1016/j.pdpdt.2021.102231
10. Song X, Li L, Gou H, Xu Y. Impact of implant location on the prevalence of peri-implantitis: A systematic review and meta- analysis. J Dent. 2020;103:103490.
Development of Dental implants
56 2021
doi:10.1016/j.jdent.2020.103490
11. Kotsailidi EA, Michelogiannakis D, Al-Zawawi AS, Javed F. Surgical or non-surgical treatment of peri-implantitis — what is the verdict?,. Surg Pract Sci.
2020;1:100010. doi:10.1016/j.sipas.2020.100010
12. Oliveira J. Deposition of Zn-ZnO nanoparticles by magnetron sputtering onto tantalum substrates. Published online 2017.
13. Wirth J, Tahriri M, Khoshroo K, Rasoulianboroujeni M, Dentino A, Tayebi L.
Surface modification of dental implants. In: Biomaterials for Oral and Dental Tissue Engineering. ; 2017:85-96. doi:10.1016/B978-0-08-100961-1.00006-2 14. Krishnakumar S, Senthilvelan T. Polymer composites in dentistry and orthopedic
applications-a review. Mater Today Proc. Published online October 2, 2020.
doi:10.1016/j.matpr.2020.08.463
15. Perrotti V, Iaculli F, Fontana A, Piattelli A, Iezzi G. Introduction to bone response to dental implant materials. In: Bone Response to Dental Implant Materials. Elsevier Inc.; 2017:1-23. doi:10.1016/B978-0-08-100287-2.00001-X
16. Lemons JE, Misch-Dietsh F, McCracken MS. Biomaterials for Dental Implants. In:
Dental Implant Prosthetics. Elsevier Inc.; 2015:66-94. doi:10.1016/B978-0-323-07845-0.00004-X
17. Chen CS, Chang JH, Srimaneepong V, et al. Improving the in vitro cell differentiation and in vivo osseointegration of titanium dental implant through oxygen plasma immersion ion implantation treatment. Surf Coatings Technol.
2020;399:126125. doi:10.1016/j.surfcoat.2020.126125
18. Fialho L, Grenho L, Fernandes MH, Carvalho S. Porous tantalum oxide with osteoconductive elements and antibacterial core-shell nanoparticles: A new generation of materials for dental implants. Mater Sci Eng C. 2021;120:111761.
doi:10.1016/j.msec.2020.111761
19. Kommel L, Shahreza BO, Mikli V. Microstructure and physical-mechanical properties evolution of pure tantalum processed with hard cyclic viscoplastic deformation. Int J Refract Met Hard Mater. 2019;83:104983.
doi:10.1016/j.ijrmhm.2019.104983
20. Black J. Biologic performance of tantalum. Clin Mater. 1994;16(3):167-173.
doi:10.1016/0267-6605(94)90113-9
BIBLIOGRAPHY
Pedro Agostinho 57
21. MOSHIER RW. INTRODUCTION. In: Analytical Chemistry of Niobium and Tantalum. Elsevier; 1964:1-10. doi:10.1016/b978-0-08-010418-8.50004-7
22. Niu Y, Chen M, Wang J, et al. Preparation and thermal shock performance of thick α-Ta coatings by direct current magnetron sputtering (DCMS). Surf Coatings Technol. 2017;321:19-25. doi:10.1016/j.surfcoat.2017.04.045
23. Garg SP, Krishnamurthy N, Awasthi A, Venkatraman M. The O-Ta (Oxygen-Tantalum) system. J Phase Equilibria. 1996;17(1):63-77. doi:10.1007/BF02648373 24. Almeida Alves CF, Calderon VS, Ferreira PJ, Marques L, Carvalho S. Passivation
and dissolution mechanisms in ordered anodic tantalum oxide nanostructures. Appl Surf Sci. 2020;513:145575. doi:10.1016/j.apsusc.2020.145575
25. Huang HL, Tsai MT, Lin YJ, Chang YY. Antibacterial and biological characteristics of tantalum oxide coated titanium pretreated by plasma electrolytic oxidation. Thin Solid Films. 2019;688:137268. doi:10.1016/j.tsf.2019.04.043
26. Anil S, Venkatesan J, Shim MS, Chalisserry EP, Kim SK. Bone response to calcium phosphate coatings for dental implants. In: Bone Response to Dental Implant
Materials. Elsevier Inc.; 2017:65-88. doi:10.1016/B978-0-08-100287-2.00004-5 27. Njuguna J, Ansari F, Sachse S, Zhu H, Rodriguez VM. Nanomaterials, nanofillers,
and nanocomposites: Types and properties. In: Health and Environmental Safety of Nanomaterials: Polymer Nancomposites and Other Materials Containing
Nanoparticles. Elsevier Ltd.; 2014:3-27. doi:10.1533/9780857096678.1.3
28. Leon L, Chung EJ, Rinaldi C. A brief history of nanotechnology and introduction to nanoparticles for biomedical applications. In: Nanoparticles for Biomedical
Applications: Fundamental Concepts, Biological Interactions and Clinical Applications. Elsevier; 2019:1-4. doi:10.1016/B978-0-12-816662-8.00001-1 29. Paris JL, Vallet-Regí M. Nanostructures for imaging, medical diagnostics and
therapy. In: Fundamentals of Nanoparticles: Classifications, Synthesis Methods, Properties and Characterization. Elsevier; 2018:1-28. doi:10.1016/B978-0-323-51255-8.00001-X
30. Martínez R, Navarro Poupard MF, Álvarez A, et al. Nanoparticle behavior and stability in biological environments. In: Nanoparticles for Biomedical Applications:
Fundamental Concepts, Biological Interactions and Clinical Applications. Elsevier;
2019:5-18. doi:10.1016/B978-0-12-816662-8.00002-3
Development of Dental implants
58 2021
31. Allaker RP, Memarzadeh K. Nanoparticles and the control of oral infections. Int J Antimicrob Agents. 2014;43(2):95-104. doi:10.1016/j.ijantimicag.2013.11.002 32. Nguyen Tri P, Nguyen TA, Nguyen TH, Carriere P. Antibacterial Behavior of
Hybrid Nanoparticles. In: Noble Metal-Metal Oxide Hybrid Nanoparticles:
Fundamentals and Applications. Elsevier; 2018:141-155. doi:10.1016/B978-0-12-814134-2.00007-3
33. THOMPSON NR. SILVER. In: The Chemistry of Copper, Silver and Gold.
Elsevier; 1973:79-128. doi:10.1016/B978-0-08-018860-7.50007-4
34. Kunkalekar RK. Role of Oxides (Fe3O4, MnO2) in the Antibacterial Action of Ag-Metal Oxide Hybrid Nanoparticles. In: Noble Ag-Metal-Ag-Metal Oxide Hybrid
Nanoparticles: Fundamentals and Applications. Elsevier; 2018:303-312.
doi:10.1016/B978-0-12-814134-2.00010-3
35. Manninen NKA de S. Silver segregation in Ag/a-C nanocomposite coatings for potential application as antibacterial surfaces. Published online 2015.
36. Prabhu S, Poulose EK. Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects. Int Nano Lett. 2012;2(1):32.
doi:10.1186/2228-5326-2-32
37. Shan D, Tao B, Fang C, et al. Anodization of titanium in reduced graphene oxide-citric acid electrolyte. Results Phys. 2021;24:104060.
doi:10.1016/j.rinp.2021.104060
38. Kozhukhova AE, du Preez SP, Shuro I, Bessarabov DG. Development of a low purity aluminum alloy (Al6082) anodization process and its application as a platinum-based catalyst in catalytic hydrogen combustion. Surf Coatings Technol.
2020;404:126483. doi:10.1016/j.surfcoat.2020.126483
39. Wang L-N, Jin M, Zheng Y, Guan Y, Lu X, Luo J-L. Nanotubular surface
modification of metallic implants via electrochemical anodization technique. Int J Nanomedicine. 2014;9:4421-4435. doi:10.2147/IJN.S65866
40. C.A. Grimes GKM. TiO2 Nanotube Arrays. Springer; 2009. doi:10.1007/978-1-4419-0068-5
41. Cordeiro JM, Nagay BE, Ribeiro ALR, et al. Functionalization of an experimental Ti-Nb-Zr-Ta alloy with a biomimetic coating produced by plasma electrolytic oxidation. J Alloys Compd. 2019;770:1038-1048. doi:10.1016/j.jallcom.2018.08.154
BIBLIOGRAPHY
Pedro Agostinho 59
42. Pesode P, Barve S. Surface modification of titanium and titanium alloy by plasma electrolytic oxidation process for biomedical applications: A review. Mater Today Proc. Published online December 24, 2020. doi:10.1016/j.matpr.2020.11.294 43. Babaei K, Fattah-alhosseini A, Chaharmahali R. A review on plasma electrolytic
oxidation (PEO) of niobium: Mechanism, properties and applications. Surfaces and Interfaces. 2020;21:100719. doi:10.1016/j.surfin.2020.100719
44. Wang H, Chu PK. Surface Characterization of Biomaterials. In: Characterization of Biomaterials. Elsevier Inc.; 2013:105-174.
doi:10.1016/B978-0-12-415800-9.00004-8
45. Ebnesajjad S. Surface and Material Characterization Techniques. In: Surface Treatment of Materials for Adhesive Bonding. Elsevier; 2014:39-75.
doi:10.1016/b978-0-323-26435-8.00004-6
46. Zhang H. Surface Characterization Techniques for Polyurethane Biomaterials. In:
Advances in Polyurethane Biomaterials. Elsevier Inc.; 2016:23-73.
doi:10.1016/B978-0-08-100614-6.00002-0
47. Salame PH, Pawade VB, Bhanvase BA. Characterization tools and techniques for nanomaterials. In: Nanomaterials for Green Energy. Elsevier; 2018:83-111.
doi:10.1016/B978-0-12-813731-4.00003-5
48. Duman M, Neundlinger I, Zhu R, et al. Atomic force microscopy. In:
Comprehensive Biophysics. Vol 2. Elsevier Inc.; 2012:111-143. doi:10.1016/B978-0-12-374920-8.00213-7
49. Wright CJ, Powell LC, Johnson DJ, Hilal N. Microscopy: Atomic Force
Microscopy. In: Encyclopedia of Food Microbiology: Second Edition. Elsevier Inc.;
2014:666-675. doi:10.1016/B978-0-12-384730-0.00217-2
50. Abhilash V, Rajender N, Suresh K. X-ray diffraction spectroscopy of polymer nanocomposites. In: Spectroscopy of Polymer Nanocomposites. Elsevier Inc.;
2016:410-451. doi:10.1016/B978-0-323-40183-8.00014-8
51. Chatterjee AK. X-Ray Diffraction. In: Handbook of Analytical Techniques in Concrete Science and Technology. Elsevier; 2001:275-332. doi:10.1016/B978-081551437-4.50011-4
52. Nobre D. Insole Coatings to Prevent Diabetic Foot Infections. Published online 2021.
Development of Dental implants
60 2021
53. Manninen NK, Calderon S V., Carvalho I, Henriques M, Cavaleiro A, Carvalho S.
Antibacterial Ag/a-C nanocomposite coatings: The influence of nano-galvanic a-C and Ag couples on Ag ionization rates. Appl Surf Sci. 2016;377:283-291.
doi:10.1016/J.APSUSC.2016.03.113
ANNEX A
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ANNEX A
Firstly, a silicon substrate was ultrasonically cleaned for 10 minutes in Ethanol and 10 minutes in distilled water. Following this step, duct tape was placed on the surface of the silicon sample. Then, mimicking the steps of the silver deposition and using the values represented in Table 0.1, carbon was sputtered onto the surface for 2 hours. The prolonged deposition time was used to create a big step when the tape was removed with the objective of minimizing errors. After the deposition time was over the duct tape was removed, revealing a clean surface without carbon and creating a step between the surfaces with and without carbon. That step was then measured using a perfilometer with the T1 mechanical head, G profile, and an advance of 5.6mm. The perfilometer’s results are depicted in Figure 0.1. Using the rule of 3 I was able to calculate the thickness of the carbon layer per minute which rounded the 4nm/minute.
Deposition Time (min)
1 30 60 120
Voltage (V) 623 654 665 665
Current Density (A/m2)
96.5 91.5 88 81
Power Density (W/m2)
60000 60000 58750 54000
Table 0.1. Carbon deposition parameters.
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Figure 0.1. Perfilometer results.
[APPENDIX A]
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[APPENDIX A]
Figure 0.1. TEM grid results.