Surface Morphology Of Titanium Research Articles

Reduced TiO2 Nanotubes/Silk Fibroin/ZnO as a Promising Hybrid Antibacterial Coating.

The current research aims to elucidate the influence of reduction process of TiO2 nanostructures on the surface properties of a bioinspired Ti modified implant, considering that the interface between a biomaterial surface and the living tissue plays an important role for this interaction. The production of reduced TiO2 nanotubes (RNT) with lower band gap is optimized and their performance is compared with those of simple TiO2 nanotubes (NT). The more conductive surfaces provided by the presence of RNT on Ti, allow a facile deposition of silk fibroin (SF) film using the electrochemical deposition method. This hybrid film is then functionalized with ZnO nanoparticles, to improve the antibacterial effect of the coating. The modified Ti surface is evaluated in terms of surface chemistry, morphology and roughness, wettability, surface energy, surface charge and antibacterial properties. Surface analysis such as SEM, AFM, FTIR and contact angle measurements were performed to obtain topographical features and wettability. FT-IR analysis confirms that SF was effectively attached to TiO2 nanotubes surfaces. The electrochemical deposition of SF and SF-ZnO reduced the interior diameter of nanotubes from ~85 nm to approx. 50-60 nm. All modified surfaces have a hydrophilic character.

Retention of zirconia crown to oxidized titanium base abutment: Experimental research.

To separate the crown from the titanium base abutment, by using heat, caused oxidization of the titanium base abutment. The effect of this procedure on the retention of a crown is unclear. To compare the resin bond strength and failure type between zirconia crowns and titanium base abutments utilizing four different surface treatments. Surface roughness and morphology of each surface treatment were also investigated. Forty titanium base abutments (Variobase®) were divided into four groups, 1. Control, 2. Air abraded, 3. Oxidized, and 4. Oxidized-air abraded. Oxidized and oxidized-air abraded groups were debonded from zirconia crowns using constant dry heat at 500 ˚C. For air abraded and oxidized-air abraded groups (after oxidization), the titanium base abutments were air abraded with Al3O2. After cleaning, one specimen of each group was investigated under a non-contact profilometer (50x), then the same samples were investigated under SEM at 25,300,500,1000 magnification and EDS at 30kV of accelerated voltage. All specimens were then cemented (RelyX Ultimate). After aging, with thermocycling under 5C° to 55C°,120 seconds dwell time for 5,000 cycles, bond strength was tested and statistical differences were calculated with One-way ANOVA (p-value <0.05) follow by Tukey test. All separated crowns and titanium base abutments were investigated under a light microscope (20x), using fisher's exact test for correlation of the failure types. There was a significant difference in the mean value of tensile bond strength among the control and test groups. Comparisons between control(237.6±46.3N) and oxidized(241.7±46.3N) showed statistically different values from air abraded(372.9±113.2N) when assembled using different surface treatments of the titanium-based abutments. (p-value<0.005) As for failure type, there were statistically significant differences between control versus air abraded, control versus oxidized-air abraded, oxidized versus air abraded, and oxidized versus oxidized-air abraded. (p-value<0.001) The titanium surface morphology shown from the profilometer and SEM was coordinated. Control (Ra 333.8nm) and oxidized (Ra 321.0nm) groups surfaces showed smooth, corrugated surfaces, meanwhile air abraded (Ra 476.0nm) and oxidized-air abraded (Ra 423.8nm) groups showed rough, rugged surfaces. Heat oxidization of titanium-based abutments did not adversely affect tensile bond strength or the failure mode and surface roughness between titanium base abutments and zirconia crowns. However, air abrasion of the titanium surface increased surface roughness and retentive strength. The titanium base abutments that were oxidized under heat treatment did not have an effect on crown retention. Thoroughly air abraded the titanium abutment prior to cementation can increase cement bond strength.

&lt;p&gt;The Cleaning Effect of the Photocatalysis of TiO&lt;sub&gt;2&lt;/sub&gt;-B＠anatase Nanowires on Biological Activity on a Titanium Surface&lt;/p&gt;

BackgroundImprovements in the early osseointegration of titanium implants require investigations on the bone-implant interface, which is a critical and complex challenge. The surface cleanliness of titanium implants plays an important role at this interface. However, the implant surface would inevitably absorb contamination such as organic hydrocarbons, which is not conductive to the establishment of early osseointegration. Herein, an optimized approach for removing contamination from titanium surfaces was studied.MethodsThe TiO2-B＠anatase NWs (nanowires) were prepared on titanium substrates through a hydrothermal process. A methylene blue degradation experiment was performed to assess the photodegradation activity. The cleaning effect of the photocatalysis of TiO2-B＠anatase NWs on a titanium surface and the cellular early response was determined by analyzing cell morphology, attachment, proliferation and differentiation.ResultsThe results indicated that the photocatalysis of TiO2-B＠anatase NWs could effectively remove hydrocarbons on titanium surfaces without sacrificing the favourable titanium surface morphology. The methylene blue degradation experiment revealed that the photocatalysis of TiO2-B＠anatase NWs had powerful degradation activity, which is attributed to the presence of strong oxidants such as ·OH. In addition, compared to the merely ultraviolet-treated titanium surfaces, the titanium surfaces treated after the NWs photocatalytic cleaning process markedly enhanced cellular early response.ConclusionThe photocatalysis of TiO2-B＠anatase NWs for the removal of contamination from titanium surfaces has the potential to enable the rapid and complete establishment of early osseointegration.

Morphologically modified surface with hierarchical micro-/nano-structures for enhanced bioactivity of titanium implants

Surface morphology of titanium (Ti) implants plays an important role in regulating cell behaviors at the interface. The purpose of our study was to investigate the effect of surface structures from microscale to nanoscale on the proliferation and differentiation of precursor osteoblasts. Sandblasting and acid etching and anodic oxidation were used to fabricate the micro-structure and nano-structure on Ti surface. Physical properties including surface topography, roughness and wettability were measured by scanning electron microscopy, laser scanning microscopy and contact angle goniometry, respectively. The bioactivity and cytocompatibility of different surface morphology were investigated in vitro. The results showed that the hierarchical micro-/nano-structured surface composed of micro-valleys and self-assembly nanotubes was successfully constructed on the substrate of Ti. The hydrophilicity of the micro-/nano-structured surface was significantly heightened in comparison with the polished surface, micro-structured surface and nano-structured surface. Moreover, a compact layer of hydroxyapatite was observed on the micro-/nano-structured surface after immersing in simulated body fluid for 14 days. Higher proliferation rate and alkaline phosphatases activity as well as enhanced biomineralization were also verified on the hierarchically structured surface. All results indicated that the integration of multiscale structures of micro-valleys and nanotubes can provide a better surrounding microenvironment to improve cell sensitivities and promote the cell proliferation and differentiation.

Influence of Temperature and Time of Acid Etching on the Surface Morphology of Titanium for Dental Implants

Research & Development in Material Science Influence of Temperature and Time of Acid Etching on the Surface Morphology of Titanium for Dental Implants Ariel Assayag, Beatriz Torres, Daniel J Fernandes* and Carlos N Elias Biomaterials Laboratory, Instituto Militar de Engenharia, Brazil *Corresponding author: Daniel J Fernandes, Biomaterials Laboratory, Instituto Militar de Engenharia, Rio de Janeiro, Brazil Submission: December 12, 2017; Published: March 23, 2018 DOI: 10.31031/RDMS.2018.04.000596 Volume 4 Issue 5 March 2018

Interrelationships among hydrogen permeation, physiochemical properties and early adsorption abilities of titanium.

This study aimed to investigate if the titanium samples with low hydrogen permeation which treated with a novel etching combination: phosphoric acid and sodium fluoride could influence the surface physiochemical properties and early adsorption ability. Titanium samples were treated with three different concentrations of the new formula, as groups A, B and C, and treated with the traditional etching formula, as group T. Zeta potential, contact angle, X-ray photoelectron spectroscopy (XPS) and fibronectin (FN)/vitronectin (VN) adsorption of Sprague-Dawley (SD) rat tibial osteotomies in the initial 30min and MG-63 adsorption in the initial 24 h were detected. Basing on the results of trails and pearson correlation analysis, the low hydrogen permeation into titanium didn't exert an impact on the surface morphology and surface stability. The adsorptions of F, P, S, acid hydroxyl and basic hydroxyl on the surfaces brought no bear on them as well. Surface concave depth and surface skewness showed highly positive correlation and moderate negative correlation with adsorption ability, respectively. Therefore, the surface morphology of titanium treated with the novel etching formula plays the only and primary role on the early adsorption. Because of its specific surface topography, group C showed the best performance which possessed slightly superiority than those of group B and group T, and with the lowest being group A. The low hydrogen permeation into titanium substrate was just benefit for improving the titanium mechanical properties, but not for the surface biochemical traits.

Effects of photodynamic laser and violet-blue led irradiation on Staphylococcus aureus biofilm and Escherichia coli lipopolysaccharide attached to moderately rough titanium surface: in vitro study.

Effective decontamination of biofilm and bacterial toxins from the surface of dental implants is a yet unresolved issue. This study investigates the in vitro efficacy of photodynamic treatment (PDT) with methylene blue (MB) photoactivated with λ 635nm diode laser and of λ 405nm violet-blue LED phototreatment for the reduction of bacterial biofilm and lipopolysaccharide (LPS) adherent to titanium surface mimicking the bone-implant interface. Staphylococcus aureus biofilm grown on titanium discs with a moderately rough surface was subjected to either PDT (0.1% MB and λ 635nm diode laser) or λ 405nm LED phototreatment for 1 and 5min. Bactericidal effect was evaluated by vital staining and residual colony-forming unit count. Biofilm and titanium surface morphology were analyzed by scanning electron microscopy (SEM). In parallel experiments, discs coated with Escherichia coli LPS were treated as above before seeding with RAW 264.7 macrophages to quantify LPS-driven inflammatory cell activation by measuring the enhanced generation of nitric oxide (NO). Both PDT and LED phototreatment induced a statistically significant (p < 0.05 or higher) reduction of viable bacteria, up to -99 and -98% (5min), respectively. Moreover, besides bactericidal effect, PDT and LED phototreatment also inhibited LPS bioactivity, assayed as nitrite formation, up to -42%, thereby blunting host inflammatory response. Non-invasive phototherapy emerges as an attractive alternative in the treatment of peri-implantitis to reduce bacteria and LPS adherent to titanium implant surface without causing damage of surface microstructure. Its efficacy in the clinical setting remains to be investigated.

레이저빔을 이용한 티타늄 표면에서의 선택적 구리 전해도금

Titanium has been used in various fields due to its good corrosion and erosion resistance, and superior mechanical properties. The process for selective electro-deposition on a titanium surface using laser beam is proposed in this paper. The process consists of laser irradiation, electro-deposition, and ultrasonic cleaning. Laser irradiation can change the surface morphology of titanium. Through laser irradiation, the surface cleaning effect and a rough surface can be achieved. The surface roughness of titanium was measured according to the laser beam conditions. The characteristics of selective electro-deposition on titanium surface according to surface roughness are investigated by various analytical methods such as SEM, and EDS.

Micro-structuring of Titanium Collectors by Laser Ablation Technique: A Promising Approach to Produce Micro-patterned Scaffolds for Tissue Engineering Applications

Multi-scale micro-structured scaffolds can sustain attachment and orientation of different cells phenotypes. An innovative use of laser ablation technique to build micro-structured titanium surfaces to be used as collectors in both electrophoretic deposition and electrospinning processes was investigated. To produce micro-patterned scaffolds, a negative replica patterning was exploited by designing specific patterns to be laser ablated on titanium plates. This method allows the deposition of the scaffolds on the mold, thus reproducing the micro-features on the scaffold surface. The titanium surface morphology depending on ablation parameters was studied and the capability of the process in replicating the micro-pattern was characterized.

The effects of diode laser on Staphylococcus aureus biofilm and Escherichia coli lipopolysaccharide adherent to titanium oxide surface of dental implants. An in vitro study.

Effective decontamination of biofilm and bacterial toxins from the surface of dental implants is a yet unresolved issue. This in vitro study aims at providing the experimental basis for possible use of diode laser (λ 808nm) in the treatment of peri-implantitis. Staphylococcus aureus biofilm was grown for 48h on titanium discs with porous surface corresponding to the bone-implant interface and then irradiated with a diode laser (λ 808nm) in noncontact mode with airflow cooling for 1min using a Ø 600-μm fiber. Setting parameters were 2W (400J/cm2) for continuous wave mode; 22μJ, 20kHz, 7μs (88J/cm2) for pulsed wave mode. Bactericidal effect was evaluated using fluorescence microscopy and counting the residual colony-forming units. Biofilm and titanium surface morphology were analyzed by scanning electron microscopy (SEM). In parallel experiments, the titanium discs were coated with Escherichia coli lipopolysaccharide (LPS), laser-irradiated and seeded with RAW 264.7 macrophages to quantify LPS-driven inflammatory cell activation by measuring the enhanced generation of nitric oxide (NO). Diode laser irradiation in both continuous and pulsed modes induced a statistically significant reduction of viable bacteria and nitrite levels. These results indicate that in addition to its bactericidal effect laser irradiation can also inhibit LPS-induced macrophage activation and thus blunt the inflammatory response. The λ 808-nm diode laser emerges as a valuable tool for decontamination/detoxification of the titanium implant surface and may be used in the treatment of peri-implantitis.

Spectroscopic and morphological study of laser ablated Titanium

The laser-induced breakdown spectroscopy (LIBS) and surface morphology of Titanium (Ti) plasma as a function of laser irradiance have been investigated under ambient environment of argon at fixed pressure of 50 Torr. Ablation was performed by employing Q-switched Nd:YAG laser pulses (λ ≈ 1064 nm, τ ≈ 10 ns, repetition rate ≈ 10 Hz). Ti targets were exposed to various laser intensities ranging from 6 to 50 GW/cm2. LIBS analysis has been employed for the investigation of plasma parameters. Scanning Electron Microscope (SEM) analysis was employed for investigation of surface morphology. Ablation depth was measured by optical microscopy technique. It was observed that both plasma parameters, i.e., excitation temperature and electron density have been significantly influenced by laser irradiance. It is observed that with increasing laser irradiance up to 13 GW/cm2, the electron temperature decreases whereas number density significantly increases and attains its maxima. Afterwards by increasing irradiance electron temperature increases, attains its maxima and a decrease in electron number density is observed at irradiance of 19 GW/cm2. Further increase in irradiance causes saturation with insignificant changes in both electron temperature and electron number density. This saturation in both excitation temperature and electron number density is explainable on the basis of self-sustaining regime. SEM micrographs reveal the ripple and coneformation at the boundaries of ablated region of Ti. The height of cones as well as the ablation depth is maximum at irradiance of 13 GW/cm2 whereas electron number density is also maximum. The maximum electron number density is considered to be responsible for maximum ablation as well as mass removal. A strong correlation between plasma parameters and surface morphology is established.

Initial oral biofilm formation on titanium implants with different surface treatments: An in vivo study

ObjectiveThe aim of this study was to examine in vivo the initial bacterial adhesion on titanium implants with different surface treatments. DesignTen subjects wore oral splints containing machined pure titanium disks (Ti-M), acid-etched titanium (Ti-AE) and anodized and laser irradiated disks (Ti-AL) for 24h. After this period, disks were removed from the splints and adherent bacteria were quantified by an enzymatic assay to assess total viable bacteria and by Real Time PCR to evaluate total bacteria and Streptococcus oralis levels. Additionally, the initial adherent microorganisms were visualized by scanning electron microscopy (SEM). Titanium surface morphology was verified using SEM, and roughness was evaluated by profilometer analysis. ResultsRegarding titanium surface roughness, Ti-AL (1.423±0.397) showed significantly higher Ra values than did Ti-M (0.771±0.182) and Ti-AE (0.735±0.196) (p<0.05, ANOVA – Tahame). Ti-AE and Ti-AL presented roughened micro-structure surfaces characterized by open pores, whereas Ti-M showed long grooves alternating with planed areas. Comparing the Ti-M, Ti-AE and Ti-AL groups for viable bacteria (MTT assay), total bacteria and S. oralis quantification (qPCR), no significant differences were observed among these three groups (p>0.05, ANOVA – Tahame). SEM images showed similar bacterial adhesion on the three titanium surfaces, predominantly characterized by cocci and several bacilli, indicating an initial colonization of the oral biofilm. ConclusionIn conclusion, roughness and microtopography did not stimulate initial biofilm formation on titanium surfaces with different surface treatments.

Effect of Heat Treatment on Surface Morphology of Titanium

Alkali and heat treatments were first introduced by Kim et al. to prepare a bioactive surface on titanium. This method has been proven very effective and widely used in biomaterial researches to promote titanium osteointegration. This study aims to investigate further the effect of heat treatment on surface morphology of high purity titanium. High purity titanium foils were immersed in 5 M NaOH at 60°C for 24 hours followed by heat treatment at 400°C, 500°C, 600°C, 700°C and 800°C for 1 hour in air atmosphere. The surface morphology was examined using Field Emission Scanning Electron Microscope (FESEM). The surface topography and surface roughness were obtained using Atomic Force Microscopy (AFM). A structure transformation accompanied by significant grain growth were observed as temperature increased from 400°C to 800°C. As temperature increased, the grain coarsened and became larger in size which is in good agreement with the increasing surface roughness. A sudden decrease in surface roughness of titanium at 800°C might be due to the spallation of oxide layer.

In vitro evaluation of peri-implantitis treatment modalities on Saos-2osteoblasts.

Mechanical treatment of the implant surface through surgical approach is recommended to control peri-implantitis. Few conclusive data exist about the physical and chemical properties of treated titanium surfaces and their biocompatibility towards osteoblasts. This invitro study aimed to evaluate four clinical procedures: plastic curette, air-abrasive device (Perio-Flow(®) ), titanium brush (Ti-Brush(®) ) and implantoplasty in terms of biocompatibility and osteogenic effect when cultured with Saos2. Titanium disks were treated with plastic curette, air-abrasive device (Perio-Flow(®) ), titanium brush (Ti-Brush(®) ) and implantoplasty. Their surface microtopography (SEM), chemical composition (EDX) and wettability were evaluated. After seeding with Saos-2, cell morphology (1h, 24h), viability (three and 6days) and alkaline phosphatase (ALP), osteoprotegerin (OPG) and osteocalcin (OCN) production (7days) were analyzed. Control, plastic curette, Perio-Flow(®) and Ti-Brush(®) groups presented complex microstructures including craters and micropits, whereas the implantoplasty group appeared much smoother (SEM). Titanium, oxygen, aluminium and carbon were identified as the main components in all disks with a decrease in the percentage of oxygen, carbon and an increase in the percentage of titanium in the implantoplasty group (EDX). Implantoplasty disks were also significantly more hydrophilic than the other ones, whose surfaces appeared hydrophobic. Saos-2 showed no morphological difference at 1h. At 24h, they appeared round shaped in all groups, except the implantoplasty group where the cells appeared stretched and elongated. Viability was similar in all groups, but significantly higher in the Perio-Flow(®) than the control group at day six. ALP, OPG and OCN protein expression at 7days was similar in all groups. Although implantoplasty was the only modality to modify the titanium surface morphology, composition and wettability, all treatment modalities promoted ALP, OPG and OCN production and appeared as valid approaches in terms of biocompatibility.

Surface treatment of titanium by a polydimethylsiloxane coating on bond strength of resin to titanium

PurposeTo evaluate the in vitro effect of titanium surface treatment by a polydimethylsiloxane coating on the shear bond strength of a resin composite cement to titanium. Materials and methodsThe titanium samples (40×30mm) were divided into 4 groups (n=12). A control group was surface treated by sandblasting using 110µm silica-coated alumina powder at a constant pressure of 300kPa for 15s/1cm2. For other three test groups, a polydimethylsiloxane silicone grease was applied onto the surface. The samples were subjected to thermal treatment in air at temperatures of 800°C, 1000°C, and 1100°C for 2h. A silane coupling agent was then applied and a resin composite stub was bonded using a polyethylene mold. The samples were submitted to three different storage conditions: dry storage, water storage in deionized water at 37°C for 30 days and thermo-cycled for 6000 cycles between 5.0 and 55.0°C. The shear bond strengths of all test groups were determined using a universal testing machine. Data were analyzed by two-way ANOVA and Tukey HSD (p<0.05). The surface morphology of titanium and elemental composition were examined with SEM and EDAX. ResultsThe results showed that there was a significant difference for different surface treatments (p<0.001) and different storage conditions (p<0.01) on the mean shear bond strengths. EDAX analysis showed there was a change of elemental composition of titanium surface after thermal treatment of the coating. ConclusionSurface treatment of titanium with a polydimethylsiloxane coating at 1000°C and 1100°C curing provides sufficient resin bonding for clinical services.

Polydopamine assisted immobilisation of copper(II) on titanium for antibacterial applications

Copper(II) were immobilised onto medical titanium surface by polydopamine (PDA) chelating, to build intrinsic antibacterial implant materials for inhibition of implant infection. A scanning electrical microscope showed that the modified titanium surface morphology was a porous nanostructure. An energy dispersive spectrometer showed the existence of Cu, and X-ray photoelectron spectroscopy results further confirmed that the immobilised copper element was in the form of Cu(II). Bacteria plate colony counting results showed that modified titanium surface had decent antibacterial property, matching the ion release outcomes. It could be conclude that the PDA assisted Cu(II) immobilisation was an efficient and effective method for antibacterial modification of titanium.

Nanoporous anodic oxidation titanium enhances cell proliferation and differentiation of immortalized mouse embryonic cells

Biological integration of dental implants into the surrounding tissue determines clinical success and the attraction of bone cells. Titanium and its alloys are widely used biomaterials with high mechanical strength and excellent biocompatibility; nanotopographies are currently under investigation for efficiency in promoting cell functions. The purpose of this study was to carry out nanoporous anodic oxidation (NAO) surface treatment on titanium and to observe the responses of immortalized mouse embryonic (ME) cells. The titanium surface was modified in two ways; by NAO via hydrofluoric acid and by microporous anodic oxidation (MAO). The ME cells were solely obtained from mesenchymal mouse (embryonic day 14.5) molar tissue (tooth germ). Field emission scanning electron microscopy was used to visualize the titanium surface morphology as well as the attachment and morphological features of the ME cells. Cytotoxicity, cell proliferation, and alkaline phosphatase activity were assayed as well. The nano- and microporous structures of the modified titanium surfaces were well formed, with diameters of 100nm and 1–3μm, respectively. ME cells were well attached to the NAO and MAO treated surfaces, resulting in no cytotoxicity to ME cells. Cell proliferation was significantly higher for the cells at the NAO treated surface than cells at the MAO treated surface. Alkaline phosphatase activity on the NAO treated surface increased from 1 to 3weeks. Hence it was concluded that NAO treated surfaces provide an attractive substrate for ME cell adhesion, proliferation, and differentiation, and may serve as useful materials for the construction of dental implants.

Immunocytochemical and structural comparative study of committed versus multipotent stem cells cultured with different biomaterials

The aim of this work was the comparison of the behavior of committed (human osteoblast cells – hOB – from bone biopsies) versus multipotent (human dental pulp stem cells – hDPSC – from extracted teeth) cells, cultured on shot-peened titanium surfaces, since the kind of cell model considered has been shown to be relevant in techniques widely used in studies on composition/morphology of biomaterial surfaces. The titanium surface morphology, with different roughness, and the behavior of cells were analyzed by confocal microscope (CM), scanning electron microscope (SEM) and X-ray microanalysis. The best results, in terms of hOB adhesion/distribution, were highlighted by both CM and SEM in cultured plates having 20-μm-depth cavities. On the contrary, CM and SEM results highlighted the hDPSC growth regardless the different surface morphology, arranged in overlapped layers due to their high proliferation rate, showing their unfitness in biomaterial surface test. Nevertheless, hDPSC cultured inside 3D-matrices reproduced an osteocyte-like three-dimensional network, potentially useful in the repair of critical size bone defects. The behavior of the two cell models suggests a different use in biomaterial cell cultures: committed osteoblast cells could be appropriate in selecting the best surfaces to improve osseointegration, while multipotent cells could be suitable to obtain in vitro osteocyte-like network for regenerative medicine. The originality of the present work consists in studying for the first time two different cell models (committed versus multipotent) compared in parallel different biomaterial cultures, thus suggesting distinct targets for each cellular model.

The influence of nano-scale surface roughness on bacterial adhesion to ultrafine-grained titanium

We discuss the effect of extreme grain refinement in the bulk of commercial purity titanium (CP, Grade-2) on bacterial attachment to the mechano-chemically polished surfaces of the material. The ultrafine crystallinity of the bulk was achieved by severe plastic deformation by means of equal channel angular pressing (ECAP). The chemical composition, wettability, surface topography and roughness of titanium surfaces were characterized using X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurements, as well as atomic force microscopy (AFM) with 3D interactive visualization of the titanium surface morphology. It was found that physico-chemical surface characteristics of the as-received and the ECAP-modified CP titanium did not differ in any significant way, while the surface roughness at the nano-scale did. Optical profilometry performed on large scanning areas of approximately 225 μm × 300 μm showed that there was no significant difference between the roughness parameters R a and R q for surfaces in the two conditions, the overall level of roughness being lower for the ECAP-processed one. By contrast, topographic profile analysis at the nano-scale by AFM did reveal a difference in these parameters. This difference was sensitive to the size of the scanned surface area. A further two surface roughness parameters, skewness ( R skw) and kurtosis ( R kur), were also used to describe the morphology of titanium surfaces. It was found that the bacterial strains used in this study as adsorbates, viz. Staphylococcus aureus CIP 65.8 and Pseudomonas aeruginosa ATCC 9025, showed preference for surfaces of ECAP-processed titanium. S. aureus cells were found to have a greater propensity for attachment to surfaces of ECAP-modified titanium, while the attachment of P. aeruginosa, while also showing some preference for the ECAP-processed material, was less sensitive to the ECAP processing.

Improvement in the morphology of micro-arc oxidised titanium surfaces: A new process to increase osteoblast response

This study describes a method for combining sandblast-acid etching and micro-arc oxidation to optimise titanium implant surfaces, and examines the effects of these surfaces on osteoblast response. Titanium discs were grouped as: micro-arc oxidised (MAO), sandblast-acid etched and micro-arc oxidised (MAO-SA), micro-arc oxidised and heated (MAO-HT), and untreated smooth surface. The combination of sandblast-acid etching and micro-arc oxidation in the MAO-SA group created an average surface roughness of 2.02 ± 0.15 μm compared to the untreated machined surface of 0.31 ± 0.06 μm. Scanning electron microscopy observations of the surface structures showed that the irregularly ordered valleys created by sandblast-acid etching remained after micro-arc oxidation and that micropores had also formed. These microstructures provided a better place for osteoblasts to spread compared with the other surfaces. In addition, our results indicated that adherent osteoblasts expressed greater alkaline phosphatase (ALP) activity and osteocalcin (OC) production on MAO-SA surfaces compared with MAO, MAO-HT, and smooth surfaces. The overall results clearly indicate that combining sandblast-acid etching and micro-arc oxidation techniques improves the titanium surface morphology and increases the roughness, which provides an optimal surface for cell differentiation and osseointegration.