Surface Characteristics Of Titanium Research Articles

Preparation of Bio-Composite Coatings on Titanium Substrate by Electrostatic Spray Deposition

In this research, the most modern deposition technique used will be utilized for biomedical applications is Electrostatic Spray Deposition (ESD), which focused on enhancing the corrosion resistance as well as biocompatibility of commercially pure titanium substrate by constructing bio composite coating, various percentages (2, 6, and 10) wt.% of Hydroxyapatite (HAP) powder were combined with (98, 94, and 90) wt.% of polymethyl methacrylate (PMMA) powder, and the same percentages (2, 6, and 10) wt.% of Nickel Oxide (NiO) powder also combined with (98, 94, and 90) wt.% of PMMA. The effects of HAP and NiO percentages in the PMMA matrix on the surface characteristics of titanium were analyzed. The FESEM, XRD, contact angle, and anti-bacterial test demonstrated that the coating layer was successfully made consistent throughout and devoid of cracks. the samples exhibited favorable wetting qualities and inhibited bacterial growth.

The influence on surface characteristic and biocompatibility of nano-SnO2-modified titanium implant material using atomic layer deposition technique

To investigate the surface characteristics of titanium (Ti) implant materials, which were coated with different thicknesses of nanoscale tin oxide (SnO2) using the atomic layer deposition technique, and evaluated its biological performance on human embryonic palatal mesenchyme (HEPM) cells. The thickness of the coating layer on Ti was 0 (Ti0), 20nm (Ti20), 50nm (Ti50), and 100nm (Ti100), respectively. The surface morphology was observed with an SEM and AFM. The root mean square roughness of micron-scale (mRq) and nanoroughness (nRq) of Ti discs' surface were measured. The Alamar blue (AB) assay and F-actin fluorescence staining were used to evaluate the biocompatibility, and the osteocalcin (OCN) was measured to clarify the differentiation of HEPM cells on materials. In the coating groups, the mRq was decreased, but the nRq was increased. The spreading and polygonal morphology of HEPMs was apparent in coating groups. On Day 4, the survival rate of HEPM cells on Ti0 was higher than on Ti20 and Ti50. There was no significant difference on Day 7, Day 10, and Day 14. The OCN was significantly higher on Day 14 in all the coating groups than Ti0. The results showed that the cell growth was intensified with rough surfaces. However, the OCN and morphology change was prominent when the nanoroughness was increased, which meant the increased nanoroughness might enhance OCN production and improve the tendency of osseointegration. The nanoscale SnO2 coating could increase the ability of bone formation but not cell growth.

Ion induced effects and defects on surface, structural and mechanical properties of Ni ion irradiated titanium

Abstract Effect of 2 MeV Ni+ ion beam irradiation with varying fluences on the surface, structural, and mechanical characteristics of titanium will be explored. For this objective, titanium targets were exposed to nickel ions obtained from a pelletron linear accelerator with 2 MeV energy and various fluences extending from 3 × 1012 to 7 × 1015 ions/cm2. Penetration features and damage evolution of 2 MeV Ni-ion in titanium have been estimated by employing SRIM-2013 software. Various characterization tools were employed to confirm the modifications in the ion beam irradiated targets. The surface and crystallographic variations of ion beam irradiated targets were explored by employing a scanning electron microscope (SEM) and X-ray diffractometer (XRD). Tensile testing and microhardness analysis was performed by utilizing a software-controlled 50 KN universal tensile testing machine and Vickers’s hardness tester, respectively. The SEM analysis represents random and irregularly distributed sputter morphology for lower ion fluences. With the increase of ion fluence, the pores keep growing radially while the growth rate slows down. At the highest ion fluence, localized melting, evaporation and expulsion of surface material were recorded at the irradiated zone. The X-ray diffraction analysis revealed no additional phases to be developed in the Ni-ion treated titanium. However, a variation in the peak intensity and slight angle/position shifting was reported, which depicts the creation of ion-induced stresses and defects. The mechanical testing results indicated the variations in the mechanical characteristics (yield stress, ultimate tensile stress, hardness etc.) of irradiated titanium. The hardness, yield stress and ultimate tensile strength increased monotonically with the increase of ion fluence. The reported modifications in the mechanical characteristics of irradiated titanium are in good accordance with structural and surface modifications. The stated changes in the irradiated titanium are ascribed to the development of ions induced stress as well to creation, augmentation/expansion, recombination, and annihilation of the ion-induced defects.

Titanium Surface Characteristics Induce the Specific Reprogramming of Toll-like Receptor Signaling in Macrophages.

Most of the research on titanium-based dental implants (Ti-discs) is focused on how they are able to stimulate the formation of new tissue and/or cytotoxic studies, with very scarce data on their effects on functional responses by immunocompetent cells. In particular, the link between the rewiring of innate immune responses and surface biomaterials properties is poorly understood. To address this, we characterize the functional response of macrophage cultures to four different dental titanium surfaces (MA: mechanical abrasion; SB + AE: sandblasting plus etching; SB: sandblasting; AE: acid etching). We use different Toll-like receptor (TLR) ligands towards cell surface receptors (bacterial lipopolysaccharide LPS for TLR4; imiquimod for TLR7; synthetic bacterial triacylated lipoprotein for TLR2/TLR1) and endosomal membrane receptor (poly I:C for TLR3) to simulate bacterial (cell wall bacterial components) or viral infections (dsRNA and ssRNA). The extracellular and total LDH levels indicate that exposure to the different Ti-surfaces is not cytotoxic for macrophages under resting or TLR-stimulated conditions, although there is a tendency towards an impairment in macrophage proliferation, viability or adhesion under TLR4, TLR3 and TLR2/1 stimulations in SB discs cultures. The secreted IL-6 and IL-10 levels are not modified upon resting macrophage exposure to the Ti-surfaces studied as well as steady state levels of iNos or ArgI mRNA. However, macrophage exposure to MA Ti-surface do display an enhanced immune response to TLR4, TLR7 or TLR2/1 compared to other Ti-surfaces in terms of soluble immune mediators secreted and M1/M2 gene expression profiling. This change of characteristics in cellular phenotype might be related to changes in cellular morphology. Remarkably, the gene expression of Tlr3 is the only TLR that is differentially affected by distinct Ti-surface exposure. These results highlight the relevance of patterned substrates in dental implants to achieve a smart manipulation of the immune responses in the context of personalized medicine, cell-based therapies, preferential lineage commitment of precursor cells or control of tissue architecture in oral biology.

The Oxidative Response of Human Monocytes to Surface Modified Commercially Pure Titanium.

Cellular responses to implanted biomaterials are key to understanding osseointegration. The aim of this investigation was to determine the in vitro priming and activation of the respiratory burst activity of monocytes in response to surface-modified titanium. Human peripheral blood monocytes of healthy blood donors were separated, then incubated with surface-modified grade 2 commercially pure titanium (CPT) disks with a range of known surface energies and surface roughness for 30- or 60-min. Secondary stimulation by phorbol 12-myrisate 13-acetate (PMA) following the priming phase, and luminol-enhanced-chemiluminescence (LCL) was used to monitor oxygen-dependent activity. Comparison among groups was made by incubation time using one-way ANOVA. One sample from each group for each phase of the experiment was viewed under scanning electron microscopy (SEM) and qualitative comparisons made. The results indicate that titanium is capable of priming peripheral blood monocytes following 60-min incubation. In contrast, 30 min incubation time lead to reduced LCL on secondary stimulation as compared to cells alone. At both time intervals, the disk with the lowest surface energy produced significantly less LCL compared to other samples. SEM examination revealed differences in surface morphology at different time points but not between differently surface-modified disks. These results are consistent with the hypothesis that the titanium surface characteristics influenced the monocyte activity, which may be important in regulating the healing response to these materials.

Histological and Histomorphometric Comparison of Innovative Dental Implants Laser Obtained: Animal Pilot Study.

Objective: Evaluation of the in vivo bone response of two innovative titanium surfaces ytterbium laser active fiber obtained (L1-L2) compared to a sandblasted and acid etched (SBAE) during early phase of osseointegration. Material and Methods: Three implant groups with the same macroscopic features were obtained (L1-L2-SBAE) to promote specific surface characteristics. Scanning electron microscopy, profilometric evaluation, X-ray spectrometry, and diffraction analysis were performed. For each group, six implants were placed in the tibiae of three Peli Buey sheep, and histologic, histomorphometric analysis, bone to implant contact (BIC), and the Dynamic Osseointegration index (DOI) were performed. Results: During the early phases of osseointegration, the histological and histomorphometric results showed significant differences between L1-L2-SBAE implants. At 15 and 30 days, histological analysis detected a newly bone formation around all specimens with an higher vital bone in L2 compared to L1 and SBAE both in cortical and in poor-quality marrow bone. At same time, histomorphometric analysis showed significantly higher BIC values in L2 (42.1 ± 2.6 and 82.4 ± 2.2) compared to L1 (5.2 ± 3.1 and 56.2 ± 1.3) and SBAE (23.3 ± 3.9 and 77.3 ± 0.4). DOI medium value showed a higher rate in L2 (2.83) compared to SBAE (2.60) and L1 (1.91). Conclusions: With the limitations of this pilot study, it is possible to assess that the titanium surface characteristics, and not the technologies used to obtain the modification, played a crucial role during the osseointegration process. Histological, histomorphometric, BIC, and DOI evaluation showed a significantly higher rate in L2 specimens compared to others, confirming that the implant surface could increase the bone response in cortical or marrow poor quality bone during the initial phases of osseointegration.

Research progress on the osseointegration of titanium implants promoted by cold atmospheric plasma

The application of cold atmospheric plasma to titanium surface modification has recently become a research focus in the area of material modification. Previous studies found that cold atmospheric plasma can affect the colonization of bacteria and biological behaviors of osteoblasts by changing the surface characteristics of titanium in vitro. In vivo studies reveal that cold atmospheric plasma can promote the process of osseointegration of titanium implants. This review focuses on research on the effects of the surface modification of titanium implants with cold atmospheric plasma on osseointegration.

Improvement in the chemical structure and biological activity of surface titanium after exposure to UVC light.

Ultraviolet (UV) irradiation has been proposed as a method to reverse the aging process of titanium. However, the intensity, exposure time and wavelength that provide the best results have not yet been determined. The objective of this study was to evaluate the effects of photocatalysis by ultraviolet C light on the time-dependent aging of titanium and to analyze the irradiated titanium for changes in structure and in vitro biological activity, with regard to different exposure times. A titanium photofunctionalization device was developed with characteristics different from those on the market. The sample was composed of titanium disks irradiated for different times of exposure to ultraviolet C light (0, 15, 30 and 60min). The disks were tested for surface wettability (water contact angle), topography (scanning electron microscopy-SEM) and chemical composition (X-ray photoelectron spectroscopy), and effects on cell adhesion (cell culture and SEM) and cell viability by sulforhodamine B (SRB). Ultraviolet C treatment caused changes in titanium surface characteristics, such as increased wettability and removal of hydrocarbons from the surface after 15min of exposure in the chamber developed. The biological characteristics of the material also appear to have changed, with improved cell adhesion and viability. Photofunctionalization of titanium proved to be effective for the treatment of aged surfaces, with significant modifications in the surface chemical structure and biological activity of the material.

Epigenetic changes of osteoblasts in response to titanium surface characteristics.

We aimed to investigate the influence of titanium surface characteristics on epigenetic mechanisms and DNA damage/repair pathways. Osteoblast-like cells (MG63) were incubated on glass, smooth titanium, and minimally rough titanium discs, respectively, for 0, 1, 6, and 24 hr. The presence of double-stranded DNA damage (γH2AX), DNA repair (Chk2), and epigenetic markers (AcH3 & DNMT1) were investigated using immunofluorescence. There were no Chk2-positive cells on the minimally rough titanium surfaces at all-time points, in comparison to glass and smooth titanium. Total γH2AX-positive cells on minimally rough titanium gradually decreased as incubation time increased, on the contrary to smooth titanium. Minimally rough titanium surfaces induced cytoplasmic staining of DNMT1 up to 99% at 24 hr. For epigenetic markers related to the DNA damage/repair pathway, minimally rough titanium surfaces showed the lower percentage of AcH3-positive cells compared to glass and smooth titanium surface. The findings in the current study show that titanium surface characteristics indeed influence DNA damage and the DNA repair pathway, including epigenetic factors.

Optimization of preparation technology on fibre metal laminates (FMLs) for high-temperature applications

Fibre metal laminates based on titanium and carbon fibre reinforced polyimide (TCP-FML) are designed and manufactured to meet the requirements of high temperature applications. In this work, the preparation technology of the TCP-FML was optimized through the investigation of prepreg manufacture as well as surface treatment of titanium. Prepreg were manufactured using a solution dip method. The effects of step width, fibre tension and translational speed on the performance of prepreg were studied. Surface treatments were performed on titanium using sandblasting, chromic acid (CAA) anodization and NaTESi anodization methods. SEM observation and contact angle were used to analyze the surface characteristics of titanium. The effects of surface treatment on the interlaminar properties of titanium/polyimide were investigated by single-lap shear test and double cantilever beam (DCB) tests. This careful surface preparation, to ensure a good interfacial strength, is crucial for good mechanical properties.

Surface properties of Ti-6Al-4V alloy treated by plasma ion nitriding process

Titanium and its alloys are most widely used in variety of applications due to its special properties viz, good strength, corrosion resistance, biocompatibility, less weight. Due to poor surface characteristics of titanium and its alloys, these are normally surface treated in order to improve the surface properties. Among the all processes, plasma ion nitriding is most common method employed to improve the surface properties of titanium and its alloys. The effect of plasma ion nitriding on mechanical properties, corrosion properties and wear properties of Ti6Al4V alloy has been investigated in this present investigation. The plasma ion nitriding has been carried out under the 80% nitrogen and 20% hydrogen atmosphere at the temperature of 500 °C for 8 h to study the improvements in the surface properties with respect to the base material surface properties. EDS analyses substantiated the formation nitrides in the surface layer. The wear test was performed in dry sliding conditions and the corrosion test was carried out in strong hydrogen sulphate solution. The sample treated with plasma ion nitriding exhibited good corrosion resistance, wear resistance and high hardness compare to base material.

Effects of Novel Laser Dental Implant Microtopography on Human Osteoblast Proliferation and Bone Deposition

The aim of this study was to compare how two innovative laser titanium surfaces and sandblasted and acid-etched surfaces influence human osteoblast behavior during osteogenesis and the initial phases of bone deposition. Human osteoblasts from human adipose stem cells were sorted by flow cytometric analysis and induced to differentiate. After 40 days, the osteogenic differentiation was detected by alizarin red staining, and the alkaline phosphatase (ALP) was evaluated with western blot (WB) and real-time reverse transcriptase-polymerase chain reaction (RT-PcR) analysis. After confluence, human osteoblasts were cultured onto two different innovative laser-obtained titanium surfaces (L1 and L2) and compared with one sandblasted and acid-etched (SBAE) surface as the control. At different times, human osteoblast behavior was evaluated with cell proliferation viability assay (MTT), scanning electron microscopy (SEM), energy-dispersive x-rays (EDAX), osteogenic markers with RT-PcR, and WB analysis of matrix extracellular phosphoglycoprotein (MEPE), ALP, and osteocalcin (OCN). After cell sorting, the human osteoblasts from human adipose stem cells showed increasing values of ALP mRNA and protein expression. The osteogenic differentiation was confirmed by quantitative alizarin red staining assay. Profilometric and SEM analysis showed relevant differences between SBAE, L1, and L2 specimens. After 20 days of culture onto titanium samples, SEM evaluation showed a small number of human osteoblasts and isolated sites of bone matrix deposition in SBAE specimens. At the same time, on L1 surfaces, only an osteoblast mono-layer with initial bone deposition was found, while on L2 specimens, there was a thick network with flattened large stellate cells, many cellular interconnections with strong titanium adhesion, and a large complex mineralized structure of crystal bone. After 20 days, for all titanium samples, human osteoblasts culturing EDAX analysis showed the absence of impurities and a higher bone matrix deposition in L2 specimens compared with L1 and SBAE samples. The innovative microtopography and nanotopography laser-induced surface showed high biocompatibility with primary human osteoblast cultures and the absence of impurities. The innovative laser texture was capable of influencing the osteogenic process, confirming the critical role of titanium surface characteristics in the cell adhesion and bone deposition during the early phases of osseointegration. The association of human adipose stem cells and titanium surfaces laser-induced with an innovative procedure could generate promising improvements and developments in orthopedics, maxillofacial, and dental implant surgery.

Thermal-induced hydrophilicity enhancement of titanium dental implant surfaces.

Titanium surface characteristics, including microtopography, chemical composition, and wettability, are essential features to achieve osseointegration of dental implants, but the choice of a particular surface topography is still a debated topic among clinicians. An increased level of implant surface hydrophilicity has been demonstrated to ameliorate osseointegration and shorten healing times. The aim of this work is to develop and test a suitable thermal-based method to enhance titanium surface wettability without modifying other characteristics of the implant surface. For this function, titanium discs with different surface topography have been thermally treated by testing different temperatures and excluding those that led to evident chromatic and morphological modifications. The selected surface gain in wettability after the treatment was assessed through contact angle measurement, chemistry modifications through x-ray photoelectron spectroscopy (XPS) analysis, and microtopography through scanning electron microscopy (SEM). Results showed a great enhancement in hydrophilicity on the tested surfaces without any other modification in terms of surface chemical composition and topography. A possible limitation of this method could be the persistent, although relatively slow, biological aging of the surfaces after the treatment. The present findings indicate that the described treatment could be a safe and effective method to enhance dental titanium hydrophilicity and thus its biological performance.

Surface characteristics of pure titanium loaded graphene oxide: effect on bacteria adhesion and osteoblast structure

To evaluate the process characterization of graphene oxide loaded on pure titanium surface and effect on the biological properties of Staphylococcus aureus and osteoblasts. Graphene oxide at four concentrations (20, 50, 80, and 100 µg·mL⁻¹) was loaded on the pure titanium surface via electroplating, and the morphology, properties, and hydrophilic properties were measured with a field emission scanning electron microscope, micro Raman spectrometer, and contact angle tester, respectively. In addition, Staphylococcus aureus and osteoblasts were used as models and cultured with pure titanium-graphene oxide. Then, field-emission scanning electron microscopy and laser confocal microscopy were utilized to observe the changes in the amount of bacteria and osteoblast morphology and structure, respectively. Graphene oxide at the four concentrations was successfully loaded on pure titanium surface via electroplating. It improved the hydrophilic properties of pure titanium surface, which benefitted the adhesion and growth of Staphylococcus aureus and changed the morphology and structure of the osteoblasts. The pure titanium-graphene oxide composite has no antibacterial properties and has good biocompatibility.

P15. Human mesenchymal stem cells exhibit increased proliferation on rough titanium substrates

BACKGROUND CONTEXT In the majority of orthopaedic surgeries, osseointegration between an implant and surrounding bone is crucial to achieving short- and long-term stability of the implant. Since an implant's surface properties directly influence the cellular response at the cell-material interface, a number of techniques exist to modify the surface characteristics of titanium (Ti)-based implants, with the objective of achieving improved osseointegration of the implant and surrounding bone. Many of these processes, such as grit-blasting and acid-etching, create a roughened surface in a random, poorly controlled manner. Conversely, subtractive laser-etching allows for controlled, intentionally designed micro- and nano-scale features to be imparted on a Ti surface. Biomimetic surface modifications can be created utilizing this technique. The biological reactions in response to a roughened, laser-etched Ti-based implant is not well understood. PURPOSE The objective of this study was to evaluate the effect of a roughened, laser-etched Ti6Al4V, substrate designed to mimic the trabecular-like structure of bone, on the cellular behavior of human bone-marrow derived mesenchymal stem cells (BM-MSCs). STUDY DESIGN/SETTING In vitro cell culture study. OUTCOME MEASURES Cell growth and proliferation rate over 7 days of culture were measured using the alamarBlue™ (AB) cell viability kit. At 4 hours, 3 days and 7 days of culture, the redox reaction, in which AB is reduced by the cells, was measured by absorbance readings at 570 and 600 nm. The percent of AB reduction has previously been shown to relate directly to the number of viable cells. METHODS Average 3D surface roughness (Sa) of the TAV substrates was characterized using 3D stereoscopic reconstruction of images from a scanning electron microscope. BM-MSCs were cultured for 7 days in a 24-well plate at a seeding density of 20,000 cells/well on the following substrates: tissue culture polysterene (TCPS), sTAV, rTAV (n=10 per group). Cells were given 4 hours to attach, after which cell media was changed and the TAV substrates were moved to a separate well plate to remove any unattached cells. At 4 hours, 3 days and 7 days of culture, the reduction percentage of AB was measured. The cell proliferation rate was calculated as the rate of change in average AB reduction from the 4 hour to 7 day time points. RESULTS Theaverage roughness of the sTAV and rTAV substrates were 0.36±0.06 μm and 36.3±1.5 μm, respectively. Significantly more AB reduction was found with rTAV substrates compared to sTAV at all time points (p CONCLUSIONS This study found increased cell proliferation on a rough, laser-etched TAV surface designed specifically to mimic the surface morphology of bone when compared to a smooth TAV substrate. This data confirms that surface roughness was increased in a controlled manner, by orders of magnitude, through subtractive laser-etching. It was found that this technique was successful in modifying cellular behavior and resulted in increased BM-MSC proliferation. Future work should investigate how laser-etched rTAV influences cell phenotype, as well as the short- and long-term cellular response. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

Experimental Investigation of Machinability and Surface Characteristics in Microelectrical Discharge Milling of Titanium, Stainless Steel and Copper

Microelectrical discharge milling (µED-milling) possesses good processing capability to fabricate intricate shapes in any electrically conductive material. In the present work, an experimental study is carried out to investigate machinability and surface characteristics of titanium (Ti) grade 2 alloy, stainless steel 304 (SS304) and copper (Cu) undergoing microelectrical discharge milling (µED-milling) process. Voltage, feed rate (FR) and tool rotation speed (TRS) are the process parameters that are varied during machining. The response measures chosen for evaluating machinability performance are material removal rate (MRR) and tool wear rate (TWR). After performing µED-milling, topography of the fabricated microslots is characterized by optical microscopy, scanning electron microscopy and surface roughness (Ra) analysis, whereas material composition analysis is carried out by X-ray diffraction and energy-dispersive X-ray techniques. It is found that Cu exhibits higher MRR than Ti and SS304, whereas SS304 exhibits higher TWR than Ti and Cu at all the chosen parametric conditions. The most significant parameter affecting MRR and TWR as ascertained by analysis of variance is FR, followed by voltage and TRS. Surface morphology of the microchannels fabricated by µED-milling reveals that globule formation and redeposition phenomenon is profound in case of Cu and SS304. In contrast, Ti grade 2 exhibits better surface morphology in terms of less globule formation, microvoids, redeposition layer and lower Ra as compared to Cu and SS304.

Effect of hydroxy groups and microtopography generated by a nanosecond-pulsed laser on pure Ti surfaces.

In this paper, we study a process for modifying the surface microtopography of the Ti oxide layer using a nanosecond-pulsed laser (NPL). Even now, the mechanism by which hydroxyl groups are generated on the titanium surface treated by NPL is not clear. Hence, we evaluated the surface properties of the NPL defocus distances on pure titanium surfaces, and investigated the relationship between the generation of hydroxyapatites/cell viability and the titanium surface characteristics. The NPL defocus distance was varied from 0 to 4 mm. Defocus distances of 0 and 2 mm generated microtopographical features on the titanium surface, and the resulting surfaces exhibited a greater density of OH groups than the surface treated with a defocus distance of 4 mm. The surfaces treated using defocus distances of 0 and 2 mm were found to be coated with microspherical hydroxyapatite composed of coexisting plate- and needle-like crystals after immersion in simulated body fluid, and alkaline phosphatase activity assays indicated improved cell compatibility. The improvements in biocompatibility and cell compatibility were due to the pocket-like microtopographical structures formed along the processing trace. These pockets contained a large amount of OH groups, and promoted the growth of hydroxyapatite.

Cigarette Smoke Extract Exposure: Effects on the Interactions between Titanium Surface and Osteoblasts.

The aim of this study was to explore the changes in the characteristics of titanium surface and the osteoblast-titanium interactions under cigarette smoke extract (CSE) exposure. In this study, CSE was used to simulate the oral liquid environment around the implant under cigarette smoke exposure. Titanium samples were immersed in CSE to explore the changes in the characteristics of titanium surface. The physical properties of titanium surface were measured, including surface micromorphology, surface elemental composition, roughness, and surface hydrophilicity. MC3T3-E1 cells were cultured on the titanium surface in vitro under different concentrations of CSE exposure, and cell adhesion, cell proliferation, and osteogenic differentiation were observed. The surface micromorphology and elemental composition of titanium surface changed under CSE exposure. No obvious changes were found in the surface roughness and the hydrophilicity of titanium samples. Moreover, the results of in vitro study showed that CSE exposure downregulated the cell spreading, proliferation, and osteogenic differentiation of MC3T3-E1 cells on the titanium surface. It could be speculated that some carbon-containing compounds from CSE adsorbed on the titanium surface and the osteoblast-titanium interactions were influenced under CSE exposure. It is hoped that these results could provide valuable information for further studies on smoking-mediated inhibition of implants osseointegration.

Interpenetrating polymer network adhesive bonding of PEEK to titanium for aerospace application

Abstract This investigation highlights the rationale of epoxy-novolac interpenetrating polymer network (IPN) adhesive bonding of low-pressure plasma treated polyether ether ketone (PEEK) to plasma nitrided titanium for aerospace application. Physico-chemical characterization of surface modified PEEK is carried out by surface energy measurement and X-ray photoelectron spectroscopy (XPS) analysis. Lap shear tensile tests are carried out to measure mechanical properties such as lap-shear tensile strength, Young’s modulus, percentage elongation at break (% EB) and toughness of the adhesive bonded PEEK to titanium joint. XPS analysis reveals the presence of the oxygen (O) functional group into the plasma treated PEEK surface. This polar functional group O increases the surface energy on the plasma treated PEEK surface, and consequently, the adhesive bond strength is enhanced. The values of Young’s modulus, % EB and toughness of epoxy-novolac IPN adhesive bonded plasma treated PEEK to plasma nitrided titanium are increased considerably in respect to epoxy-novolac IPN adhesive bonded untreated PEEK to untreated titanium joint. Therefore, the present investigation concludes that the adhesive bond strength not only depends on the surface characteristics of PEEK and titanium, but also on the cohesive properties of the adhesive.

Surface morphology characterization of laser-induced titanium implants: lesson to enhance osseointegration process.

The surface properties of implant are responsible to provide mechanical stability by creating an intimate bond between the bone and implant; hence, play a major role on osseointegration process. The current study was aimed to measure surface characteristics of titanium modified by a pulsed Nd:YAG laser. The results of this study revealed an optimum density of laser energy (140Jcm-2), at which improvement of osteointegration process was seen. Significant differences were found between arithmetical mean height (Ra), root mean square deviation (Rq) and texture orientation, all were lower for 140Jcm-2 samples compared to untreated one. Also it was identified that the surface segments were more uniformly distributed with a more Gaussian distribution for treated samples at 140Jcm-2. The distribution of texture orientation at high laser density (250 and 300Jcm-2) were approximately similar to untreated sample. The skewness index that indicates how peaks and valleys are distributed throughout the surface showed a positive value for laser treated samples, compared to untreated one. The surface characterization revealed that Kurtosis index, which tells us how high or flat the surface profile is, for treated sample at 140Jcm-2 was marginally close to 3 indicating flat peaks and valleys in the surface profile.