Improving Biocompatibility and Mechanical Properties of Titanium Implants in Orthopedic Surgeries: The Role of Machining Depth in Enhancing Surface Interaction with Bone Tissue

Document Type : RESEARCH PAPER

Authors

School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran

10.22038/abjs.2025.83963.3830

Abstract

Objectives: This study comprehensively examined the influence of cutting depth during dry milling on the structural, mechanical, and biocompatibility characteristics of commercially pure titanium. The primary objective was to evaluate how variations in cutting depth can alter the crystallite size, microstrain, and wear resistance, as well as to investigate their correlation with essential biocompatibility parameters including cellular interactions, osteointegration potential, and corrosion resistance in a simulated body fluid environment. Understanding these interrelations is crucial for improving the overall performance of titanium implants used in biomedical applications.
Methods: Pure titanium specimens were precisely machined at cutting depths of 0.1, 0.2, and 0.3 mm under dry conditions, ensuring that all other machining parameters remained constant. The structural characteristics were analyzed using X-ray diffraction to determine crystallite size and microstrain variations. Wear resistance was evaluated through sliding wear tests that quantified material loss, while biocompatibility performance was assessed via immersion tests in simulated body fluid. This evaluation included corrosion resistance measurements, quantification of calcium–phosphate deposition on the surface, and analysis of the initial interactions with osteoblast-like cells to determine cellular affinity and bioactivity.
Results: The experimental results indicated that increasing the cutting depth led to a significant reduction in crystallite size (28, 50, and 25 nm for 0.1, 0.2, and 0.3 mm, respectively) and a corresponding increase in microstrain (0.0011, 0.0011, and 0.009). Specimens machined at cutting depths of 0.2 and 0.3 mm exhibited superior wear resistance, with lower weight losses (7.9 and 5.3 mg) compared with the 0.1 mm specimen (12.1 mg). Biocompatibility assessments revealed that higher cutting depths enhanced corrosion resistance, promoted calcium–phosphate deposition, and improved osteointegration potential.
Conclusion: optimizing the cutting depth to 0.2–0.3 mm during dry milling can substantially improve both mechanical performance and biocompatibility, offering valuable guidance for implant manufacturing and long-term in vivo functionality.
        Level of evidence: I

Keywords

Main Subjects


  1. Li Y, Yang C, Zhao H, Qu S, Li X, Li Y. New developments of Ti-based alloys for biomedical applications. Materials (Basel). 2014;7(3):1709-1800. doi: 10.3390/ma7031709.
  2. Graul I, Marintschev I, Pizanis A, et al. Triangular Screw Placement to Treat Dysmorphic Sacral Fragility Fractures in Osteoporotic Bone Results in an Equivalent Stability to Cement-Augmented Sacroiliac Screws A Biomechanical Cadaver Study. J Clin Med. 2025;14(5):1497. doi: 10.3390/jcm14051497.
  3. Mekrane FZ, Ouladsine R, Barkaoui A, Ghandour R. Prognostics of the knee osteoarthritis induced by cyclic loading activities. A model-based analysis. Comput Methods Biomech Biomed Engin. 2025:1-14. doi: 10.1080/10255842.2025.2456993.
  4. Maeda K, Yoshida K, Nishizawa T, et al. Inflammation and bone metabolism in rheumatoid arthritis: molecular mechanisms of joint destruction and pharmacological treatments. Int J Mol Sci. 2022;23(5):2871. doi: 10.3390/ijms23052871.
  5. Soundharya V, Arthi R, Suresh Kumar I, Hari Haran A. Enhanced Bone Marrow Aspirate Concentrate (BMAC) Preparation Strategy in the Management of Chondromalacia Patella: A Case Report. Cureus. 2024;16(4):e59321. doi: 10.7759/cureus.59321.
  6. Geetha M, Singh AK, Asokamani R, Gogia AK. Ti based biomaterials, the ultimate choice for orthopaedic implants–A review. Progress in materials science. 2009;54(3):397-425.
  7. Perren SM, Pohler OE, Schneider E, eds. Titanium as implant material for osteosynthesis applications. In: Titanium in Medicine: Material Science, Surface Science, Engineering, Biological Responses and Medical Applications 2001 (pp. 771-825). Berlin, Heidelberg: Springer Berlin Heidelberg.
  8. Long MJ, Rack HJ. Titanium alloys in total joint replacements a material science perspective. Biomaterials.1998; 19(18):1621-39. doi: 10.1016/s0142-9612(97)00146-4.
  9. Jin W, Chu PK. Orthopedic implants. Encyclopedia of biomedical engineering. 2019;1(3):425-39.
  10. Sidambe AT. Biocompatibility of advanced manufactured titanium implants A review. Materials (Basel). 2014;7(12):8168-8188. doi: 10.3390/ma7128168.
  11. Niinomi M. Design and development of metallic biomaterials with biological and mechanical biocompatibility. J Biomed Mater Res A.2019;107(5):944-954. doi: 10.1002/jbm.a.36667.
  12. Chen Q, Thouas GA. Metallic implant biomaterials. Materials Science and Engineering: R: Reports. 2015;87:1-57.
  13. Gravier J, Vignal V, Bissey-Breton S. Influence of residual stress, surface roughness and crystallographic texture induced by machining on the corrosion behaviour of copper in salt-fog atmosphere. Corrosion Science. 2012;61:162-70.
  14. Saptaji K, Gebremariam MA, Azhari MA. Machining of biocompatible materials: a review. The International Journal of Advanced Manufacturing Technology. 2018;97(5):2255-92.
  15. Mhamdi MB, Boujelbene M, Bayraktar E, Zghal A. Surface integrity of titanium alloy Ti-6Al-4V in ball end milling. Physics Procedia. 2012;25:355-62.
  16. Festas A, Ramos A, Davim JP. Machining of titanium alloys for medical application-a review. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture. 2022;236(4):309-18.
  17. Wan X, Hu A, Li M, Chang C, Mao D. Performances of CaSiO3 ceramic sintered by Spark plasma sintering. Materials Characterization. 2008;59(3):256-60.
  18. Prakash M, Shekhar S, Moon AP, Mondal K. Effect of machining configuration on the corrosion of mild steel. Journal of Materials Processing Technology. 2015;219:70-83.
  19. Beltrán V, Lazzarini M, Figueroa R, Sousa V, Engelke W. In situ endoscopic analysis of vascular supply and regenerated alveolar bone in β-TCP grafted and ungrafted postextraction sites before implant placement: A prospective case-control study. Biomed Res Int. 2019:2019:2797210. doi: 10.1155/2019/2797210.
  20. Balasubramanian R, Nagumothu R, Parfenov E, Valiev R. Development of nanostructured titanium implants for biomedical implants–A short review. Materials Today: Proceedings. 2021;46:1195-200.
  21. Davis R, Singh A. Performance study of cryo-treated end mill via wet, cryogenic, and hybrid lubri-coolant-milling induced surface integrity of biocompatible Mg alloy AZ91D. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science. 2021;235(23):7045-61.
  22. Bruschi S, Pezzato L, Ghiotti A, Dabalà M, Bertolini R. Effectiveness of using low-temperature coolants in machining to enhance durability of AISI 316L stainless steel for reusable biomedical devices. Journal of Manufacturing Processes. 2019;39:295-304.
  23. Madyira DM, Laubscher RF, Van Rensburg NJ, Henning PF. High speed machining induced residual stresses in Grade 5 titanium alloy. Proceedings of the institution of mechanical engineers, part L: journal of materials: design and applications. 2013;227(3):208-15.
  24. Bertolini R, Bruschi S, Ghiotti A, Pezzato L, Dabalà M. The effect of cooling strategies and machining feed rate on the corrosion behavior and wettability of AZ31 alloy for biomedical applications. Procedia Cirp. 2017;65:7-12.
  25. Fouzia H, Mamoun F, Naouel H, et al. The effect of milling time on the microstructure and mechanical properties of Ti-6Al-4Fe alloys. Materials Today Communications. 2021;27:102428.
  26. Singh B, Saxena KK, Dagwa IM, Singhal P, Malik V. Optimization of machining characteristics of titanium-based biomaterials: approach to optimize surface integrity for implants applications. Surface Review and Letters. 2025;32(04):2340008.
  27. Patil S, Jadhav S, Kekade S, Supare A, Powar A, Singh RK. The influence of cutting heat on the surface integrity during machining of titanium alloy Ti6Al4V. Procedia Manufacturing. 2016;5:857-69.
  28. Mamedov A, Lazoglu I. Thermal analysis of micro milling titanium alloy Ti–6Al–4V. Journal of Materials Processing Technology. 2016;229:659-67.
  29. Cengiz B, Gokce Y, Yildiz N, Aktas Z, Calimli A. Synthesis and characterization of hydroxyapatite nanoparticles. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2008;322(1-3):29-33.
  30. Noordin MY, Jiawkok N, Ndaruhadi PY, Kurniawan D. Machining of bone: Analysis of cutting force and surface roughness by turning process. Proc Inst Mech Eng H. 2015;229(11):761-8. doi: 10.1177/0954411915606169.
  31. Pesode P, Barve S. Biocompatibility of Plasma Electrolytic Oxidation Coated Titanium Alloy for Biomedical Applications. Bionanoscience. 2025;15(2):232.
  32. Tanabe I, Goi Y, Tanabe Y. Research on oxidation phenomenon during titanium machining and its prevention. Journal of Machine Engineering. 2020;20.
  33. Soe YH, Tanabe I, Iyama T, Abe Y. Control of tool temperature using neural network for machining materials with low thermal conductivity. Journal of Machine Engineering. 2010;10.
  34. Ribeiro Filho SL, Lauro CH, Bueno AH, Brandao LC. Influence cutting parameters on the surface quality and corrosion behavior of Ti–6Al–4V alloy in synthetic body environment (SBF) using Response Surface Method. Measurement. 2016;88:223-37.
  35. Brunette DM, Tengvall P, Textor M, Thomsen P,eds. Titanium in medicine: material science, surface science, engineering, biological responses and medical applications. Berlin: Springer; 2001.
  36. Urbani G, Lombardo G, Santi E, Consolo U. Distraction osteogenesis to achieve mandibular vertical bone regeneration: a case report. Int J Periodontics Restorative Dent. 1999;19(4):321-31.
  37. Esposito M, Hirsch JM, Lekholm U, Thomsen P. Biological factors contributing. Eur J Oral Sci. 1998;106(3):721-64. doi: 10.1046/j.0909-8836..t01-6-.x.
  38. d'Hoedt B, Schulte W. A comparative study of results with various endosseous implant systems. Int J Oral Maxillofac Implants. 1989;4(2):95-105.
  39. M Salonen MA, Oikarinen K, Virtanen K, Pernu H. Failures in the osseointegration of endosseous implants. Int J Oral Maxillofac Implants. 1993;8(1):92-7.
  40. Mericske-Stern R, Zarb GA. Overdentures: an alternative implant methodology for edentulous patients. Int J Prosthodont. 1993;6(2):203-8.
  41. Bozorgi A, Khazaei M, Soleimani M, Jamalpoor Z. Application of nanoparticles in bone tissue engineering; a review on the molecular mechanisms driving osteogenesis. Biomater Sci. 2021;9(13):4541-4567. doi: 10.1039/d1bm00504a.
  42. He Y, Zhou H, Zhao Y, et al. Investigating the thermal stability of compressive residual stress in a gradient nanostructured austenitic stainless steel by in-situ XRD and TEM. Materials Characterization. 2024;207:113610.
  43. Tamarani A, Zainul R, Dewata I. Preparation and characterization of XRD nano Cu-TiO2 using sol-gel method. InJournal of Physics: Conference Series 2019 (Vol. 1185, p. 012020). IOP Publishing.
  44. Ramazani M, Farahmandjou M, Firoozabadi TP. Effect of nitric acid on particle morphology of the nano-TiO2. International Journal of Nanoscience and Nanotechnology. 2015;11(2):115-22.
  45. Sedehi SM, Khosravi M, Yaghoubinezhad Y. Mechanical properties and microstructures of reduced graphene oxide reinforced titanium matrix composites produced by spark plasma sintering and simple shear extrusion. Ceramics International. 2021;47(23):33180-90.
  46. Prosolov KA, Khimich MA, Sharkeev YP. Surface Treatments and Residual Stress: Assessing the Implications for Biocompatibility in Titanium Implants. Russian Physics Journal. 2023;66(1):116-23.
  47. Bemporad E, Brisotto M, Depero LE, Gelfi M, Korsunsky AM, Lunt AJ, Sebastiani M. A critical comparison between XRD and FIB residual stress measurement techniques in thin films. Thin Solid Films. 2014;572:224-31.
  48. Liu J, Liang C. Microstructure characterization and mechanical properties of bulk nanocrystalline aluminium prepared by SPS and followed by high-temperature extruded techniques. Materials Letters. 2017;206:95-9.
  49. Cao L, Sengupta A, Pantuso D, Koslowski M. Effect of texture and grain size on the residual stress of nanocrystalline thin films. Modelling and Simulation in Materials Science and Engineering. 2017;25(7):075004.
  50. Yogamalar R, Srinivasan R, Vinu A, Ariga K, Bose AC. X-ray peak broadening analysis in ZnO nanoparticles. Solid State Communications. 2009;149(43-44):1919-23.
  51. Akbas O, Reck L, Jahn A, Hermsdorf J, Stiesch M, Greuling A. Effect of Different Sandblasting Parameters on the Properties of Additively Manufactured and Machined Titanium Surfaces. In Vivo. 2025;39(3):1767-1785. doi: 10.21873/invivo.13979.
  52. Umar Farooq M, Pervez Mughal M, Ahmed N, Ahmad Mufti N, Al-Ahmari AM, He Y. On the investigation of surface integrity of Ti6Al4V ELI using Si-mixed electric discharge machining. Materials (Basel). 2020;13(7):1549. doi: 10.3390/ma13071549.
  53. Himabindu B, Devi NL, Kanth BR. Microstructural parameters from X-ray peak profile analysis by Williamson-Hall models; A review. Materials Today: Proceedings. 2021;47:4891-6.
  54. Kibasomba PM, Dhlamini S, Maaza M, et al. Strain and grain size of TiO2 nanoparticles from TEM, Raman spectroscopy and XRD: The revisiting of the Williamson-Hall plot method. Results in Physics. 2018;9:628-35.
  55. Veljović D, Čolić M, Kojić V, et al. The effect of grain size on the biocompatibility, cell–materials interface, and mechanical properties of microwave‐sintered bioceramics. J Biomed Mater Res A. 2012;100(11):3059-70. doi: 10.1002/jbm.a.34225.
  56. Kasaeian-Naeini M, Sedighi M, Hashemi R. Severe plastic deformation (SPD) of biodegradable magnesium alloys and composites: A review of developments and prospects. Journal of Magnesium and Alloys. 2022;10(4):938-55.
  57. Ramezani M, Ripin ZM. An overview of enhancing the performance of medical implants with nanocomposites. Journal of Composites Science. 2023;7(5):199.
  58. Strunz P, Kunčická L, Beran P, Kocich R, Hervoches C. Correlating microstrain and activated slip systems with mechanical properties within rotary swaged WNiCo pseudoalloy. Materials (Basel).2020;13(1):208. doi: 10.3390/ma13010208.
  59. Tjandra J, Alabort E, Barba D, Pedrazzini S. Corrosion, fatigue and wear of additively manufactured Ti alloys for orthopaedic implants. Materials Science and Technology. 2023;39(18):2951-65.
  60. Jiang W, Zhao W, Deng L, Zhou T, Qiu T. Research on theoretical and experimental investigations of burr formation mechanism in micro-milling process of medical ploy-L-lactide. Journal of Manufacturing Processes. 2024;117:1-3.
  61. Yazar KU, Mishra S, Karmakar A, Bhattacharjee A, Suwas S. On the temperature sensitivity of dwell fatigue of a near alpha titanium alloy: role of strain hardening and strain rate sensitivity. Metallurgical and Materials Transactions A. 2020;51(10):5036-42.
  62. Antil P, Kumar Antil S, Prakash C, Krolczyk G, Pruncu C. Multi-objective optimization of drilling parameters for orthopaedic implants. Measurement and Control. 2020;53(9-10):1902-10.
  63. Singh B, Saxena KK, Dagwa IM, Singhal P, Malik V. Optimization of machining characteristics of titanium-based biomaterials: approach to optimize surface integrity for implants applications. Surface Review and Letters. 2025;32(04):2340008.