This study investigated the surface characteristics of ultrafine-grain commercially pure titanium (UFG CP-Ti) substrates produced by equal channel angular pressing (ECAP), compared with those of coarse-grain commercially pure titanium (CG CP-Ti) and Ti–6Al–4V (Ti-64) substrates. All Ti surfaces were sandblasted and acid-etched (SLA-treated) to produce micro-rough surfaces. Tensile and microhardness tests were carried out to measure the mechanical properties of fabricated samples. Then the surface characteristics of samples including contact angle measurements, surface morphology and in vitro cell response were evaluated after polishing, sandblasting and acid etching procedures. The results showed that after applying four passes of ECAP, the average grain size of microstructure decreased from 25 µm to 170 nm, while the ultimate tensile strength increased from 545 ± 24 MPa to 971 ± 38 MPa. Investigation of surface morphologies carried out by scanning electron microscopy indicated that ECAP-processed substrate exhibits nano-topography compared with CG CP-Ti and Ti-64 substrates after applying SLA process. In addition, the contact angle of SLA-treated CG CP-Ti and UFG CP-Ti substrates decreased from 68.3° to 9.5° and 51.9° to 7.4°, respectively, indicating a significant improvement of surface wettability. The morphologies of MG63 cells cultured on the developed surfaces proved the potential superior osteoblast cell compatibility of the micro-roughened surface made of UFG CP-Ti substrates over CG CP-Ti and Ti-64 substrates.
EliasCN, et al.Mechanical properties, surface morphology and stability of a modified commercially pure high strength titanium alloy for dental implants. Dent Mater2015; 31: e1–e13.
2.
EftekhariM, et al.Processing and characterization of nanostructured Grade 2 Ti processed by combination of warm isothermal ECAP and extrusion. Mater Sci Eng2017; 703: 551–558.
3.
WilliamsDF. On the mechanisms of biocompatibility. Biomaterials2008; 29: 2941–2953.
4.
MahmoodianR, et al.Severe plastic deformation of commercial pure titanium (CP-Ti) for biomedical applications: a brief review. JOM2019; 71: 256–263.
5.
MishnaevskyL, et al.Nanostructured titanium-based materials for medical implants: modeling and development. Mater Sci Eng2014; 81: 1–19.
6.
CordeiroJM, et al.Development of binary and ternary titanium alloys for dental implants. Dent Mater2017; 33: 1244–1257.
7.
OkazakiY, et al.Corrosion resistance, mechanical properties, corrosion fatigue strength and cytocompatibility of new Ti alloys without Al and V. Biomaterials1998; 19: 1197–1215.
8.
AmaniSFarajiG. Processing and properties of biodegradable magnesium microtubes for using as vascular stents: a brief review. Metals Mater Int2019. https://doi.org/10.1007/s12540-019-00285-4.
9.
KimW-JHyunC-YKimH-K. Fatigue strength of ultrafine-grained pure Ti after severe plastic deformation. Scripta Mater2006; 54: 1745–1750.
10.
ReshadiF, et al.Surface modification of severe plastically deformed ultrafine grained pure titanium by plasma electrolytic oxidation. Surf Coat Technol2017; 316: 113–121.
11.
KralP, et al.Effect of severe plastic deformation on creep behaviour of a Ti–6Al–4V alloy. J Mater Sci2013; 48: 4789–4795.
12.
PushinVG, et al.Effect of severe plastic deformation on the behavior of Ti–Ni shape memory alloys. Mater Transac2006; 47: 694–697.
13.
ReshadiF, et al.Deformation speed and temperature effects on magnesium AZ91 during tubular channel angular pressing. Mater Sci Technol2015; 31: 1879–1885.
14.
FarajiGKimHKashiHT. Severe plastic deformation: methods, processing and properties, Elsevier, 2018.
15.
SegalV. Equal channel angular extrusion: from macromechanics to structure formation. Mater Sci Eng1999; 271: 322–333.
16.
BrunetteDM, et al.Titanium in medicine: material science, surface science, engineering, biological responses and medical applications, Germany: Springer Science & Business Media, 2012.
17.
Le GuéhennecL, et al.Surface treatments of titanium dental implants for rapid osseointegration. Dent Mater2007; 23: 844–854.
18.
HanCH, et al.Quantitative and qualitative investigations of surface enlarged titanium and titanium alloy implants. Clin Oral Implants Res1998; 9: 1–10.
19.
WebsterTJEjioforJU. Increased osteoblast adhesion on nanophase metals: Ti, Ti6Al4V, and CoCrMo. Biomaterials2004; 25: 4731–4739.
20.
BuserD, et al.Enhanced bone apposition to a chemically modified SLA titanium surface. J Dent Res2004; 83: 529–533.
21.
ShibataY, et al.Glow discharge plasma treatment of titanium plates enhances adhesion of osteoblast-like cells to the plates through the integrin-mediated mechanism. Int J Oral Maxillofacial Implants2002; 17: 771–2–771–2.
22.
NovaesABJr, et al.Influence of implant surfaces on osseointegration. Brazil Dent J2010; 21: 471–481.
23.
RossAPWebsterTJ. Anodizing color coded anodized Ti6Al4V medical devices for increasing bone cell functions. Int J Nanomed2013; 8: 109–109.
24.
SchliephakeH, et al.Effect of modifications of dual acid-etched implant surfaces on peri-implant bone formation. Part I: organic coatings. Clin Oral Implants Res2009; 20: 31–37.
25.
XirongYXichengZWenjieF. Deformed Microstructures and mechanical properties of CP-Ti processed by multi-pass ECAP at room temperature. Rare Metal Mater Eng2009; 38: 955–957.
26.
ShankarMR, et al.Severe plastic deformation (SPD) of titanium at near-ambient temperature. Acta Mater2006; 54: 3691–3700.
27.
Chuvil’deevV, et al.Effect of the simultaneous enhancement in strength and corrosion resistance of microcrystalline titanium alloys. Doklady Phys2012; 57: 10–2–10–2.
28.
HajizadehKAlamdariSGEghbaliB. Stored energy and recrystallization kinetics of ultrafine grained titanium processed by severe plastic deformation. Phys B2013; 417: 33–38.
29.
SuwasS, et al.Texture evolution in commercially pure titanium after warm equal channel angular extrusion. Acta Mater2011; 59: 1121–1133.
30.
ChenY, et al.Quantitative analysis of grain refinement in titanium during equal channel angular pressing. Scripta Mater2011; 64: 904–907.
31.
GunderovD, et al.Evolution of microstructure, macrotexture and mechanical properties of commercially pure Ti during ECAP-conform processing and drawing. Mater Sci Eng2013; 562: 128–136.
32.
FarajiGKimH. Review of principles and methods of severe plastic deformation for producing ultrafine-grained tubes. Mater Sci Technol2017; 33: 905–923.
33.
NiinomiM. Mechanical properties of biomedical titanium alloys. Mater Sci Eng1998; 243: 231–236.
34.
JuodzbalysGSapragonieneMWennerbergA. New acid etched titanium dental implant surface. Stomatologija Bal Den Maxillofac J2003; 5: 101–105.
35.
RosaMB, et al.The influence of surface treatment on the implant roughness pattern. J Appl Oral Sci2012; 20: 550–555.
36.
WennerbergAAlbrektssonT. Effects of titanium surface topography on bone integration: a systematic review. Clin Oral Implants Res2009; 20: 172–184.
37.
RuppF, et al.Surface characteristics of dental implants: a review. Dent Mater2017; 43: 40–2–40–2.
38.
GongadzeE, et al.Adhesion of osteoblasts to a nanorough titanium implant surface. Int J Nanomed2011; 6: 1801–1801.
39.
de JagerNFeilzerAJDavidsonCL. The influence of surface roughness on porcelain strength. Dent Mater2000; 16: 381–388.
40.
BiswasS, et al.Subsurface behavior of ductile material by particle impacts and its influence on wear mechanism. Proc Eng2014; 90: 160–165.
41.
RuppF, et al.A review on the wettability of dental implant surfaces I: theoretical and experimental aspects. Acta Biomater2014; 10: 2894–2906.
42.
PackhamDE. Surface energy, surface topography and adhesion. Int J Adhes Adhes2003; 23: 437–448.
43.
KatoESakuraiKYamadaM. Periodontal-like gingival connective tissue attachment on titanium surface with nano-ordered spikes and pores created by alkali-heat treatment. Dent Mater2015; 31: e116–e130.
44.
HitchcockSCarrollNNicholasM. Some effects of substrate roughness on wettability. J Mater Sci1981; 16: 714–732.
45.
EstrinY, et al.Accelerated stem cell attachment to ultrafine grained titanium. Acta Biomater2011; 7: 900–906.
46.
KimTN, et al.In vitro fibroblast response to ultra fine grained titanium produced by a severe plastic deformation process. J Mater Sci2008; 19: 553–557.
47.
ParkJ-W, et al.Enhanced osteoblast response to an equal channel angular pressing-processed pure titanium substrate with microrough surface topography. Acta Biomater2009; 5: 3272–3280.
48.
Maleki-GhalehH, et al.Electrochemical and cellular behavior of ultrafine-grained titanium in vitro. Mater Sci Eng2014; 39: 299–304.
49.
EliasCN, et al.Ultrafine grained titanium for biomedical applications: an overview of performance. J Mater Res Technol2013; 2: 340–350.
