Cell Adhesion and in Vivo Osseointegration of Sandblasted/Acid Etched/Anodized Dental Implants

The authors describe a new type of titanium (Ti) implant as a Modi-anodized (ANO) Ti implant, the surface of which was treated by sandblasting, acid etching (SLA), and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control), SLA, anodized, and Modi-ANO Ti. In the cell adhesion study, Modi-ANO Ti showed higher initial MG-63 cell adhesion and induced greater filopodia growth than other groups. In vivo study in a beagle model revealed the bone-to-implant contact (BIC) of Modi-ANO Ti (74.20% ± 10.89%) was much greater than those of machined (33.58% ± 8.63%), SLA (58.47% ± 12.89), or ANO Ti (59.62% ± 18.30%). In conclusion, this study demonstrates that Modi-ANO Ti implants produced by sandblasting, acid etching, and anodizing improve cell adhesion and bone ongrowth as compared with machined, SLA, or ANO Ti implants. These findings suggest that the application of Modi-ANO surface treatment could improve the osseointegration of dental implant.     

Effect of the Size of Titanium Particles Released from Dental Implants on Immunological Response

The techniques used in oral implantology to remove bacterial biofilm from the surface of implants by machining the titanium surface (implantoplasty) or by placing rough dental implants through friction with the cortical bone generate a large release of particles. In this work, we performed a simulation of particle generation following clinical protocols. The particles were characterized for commercially pure titanium with particle sizes of 5, 10, 15, and 30 μm. The aim was to determine the effect of particle size and chemical composition of the implant on the immune response. For this purpose, their morphology and possible contamination were characterized by scanning electron microscopy and X-ray microanalysis. In addition, the granulometry, specific surface area, release of metal ions into the medium, and studies of cytocompatibility, gene expression, and cytokine release linked to the inflammatory process were studied. The release of ions for titanium particles showed levels below 800 ppb for all sizes. Smaller particle sizes showed less cytotoxicity, although particles of 15 μm presented higher levels of cytocompatibility. In addition, inflammatory markers (TNFα and Il-1β) were higher compared to larger titanium. Specifically, particles of 15 μm presented a lower proinflammatory and higher anti-inflammatory response as characterized by gene expression and cytokine release, compared to control or smaller particles. Therefore, in general, there is a greater tendency for smaller particles to produce greater toxicity and a greater proinflammatory response.     

Stable superhydrophobic surface of hierarchical carbon nanotubes on Si micropillar arrays

It is of great importance to construct a stable superhydrophobic surface with low sliding angle (SA) for various applications. We used hydrophobic carbon nanotubes (CNTs) to construct the superhydrophobic hierarchical architecture of CNTs on silicon micropillar array (CNTs/Si-μp), which have a large contact angle of 153° to 155° and an ultralow SA of 3° to 5°. Small water droplets with a volume larger than 0.3 μL can slide on the CNTs/Si-μp with a tilted angle of approximately 5°. The CNTs growing on planar Si wafer lose their superhydrophobic properties after exposing to tiny water droplets. However, the CNTs/Si-μp still show superhydrophobic properties even after wetting using tiny water droplets. The CNTs/Si-μp still have a hierarchical structure after wetting, resulting in a stable superhydrophobic surface.     

The Topographical Optimization of 3D Microgroove Pattern Intervals for Ligamentous Cell Orientations: In Vitro

Specific orientations of periodontal ligaments (PDLs) to tooth-root surface play an important role in offering positional stabilities of teeth, transmitting and absorbing various stresses under masticatory/occlusal loading conditions, or promoting tissue remodeling by mechanical stimulations to periodontal cells. However, it is still challenging to spatially control PDL orientations and collective PDL cell alignments using 3D scaffold architectures. Here, we investigated the optimization of scaffold topographies in order to control orientations of human PDL cells with predictability in in vitro. The 3D PDL-guiding architectures were designed by computer-aided design (CAD) and microgroove patterns on the scaffold surfaces were created with four different slice intervals such as 25.40 µm (μG-25), 19.05 µm (μG-19), 12.70 µm (μG-12), and 6.35 µm (μG-6) by the digital slicing step. After scaffold design and 3D wax printing, poly-ε-caprolactone (PCL) was casted into 3D printed molds and human PDL cells were cultured for 7 days. In the results, μG-25 with low vertical resolution can angularly organize seeded cells predictably rather than μG-6 created by the highest resolution for high surface quality (or smooth surface). Moreover, nuclear orientations and deformability were quantitatively analyzed and a significant correlation between microgroove pattern intervals and cell alignments was calculated for the topographic optimization. In conclusion, controllable microgroove intervals can specifically organize human PDL cells by 3D printing, which can create various surface topographies with structural consistence. The optimal surface topography (μG-25) can angularly guide human PDL cells, but 6.35 µm-thick patterns (μG-6) showed random organization of cell collectivity.     

A novel effect of sandblasting on titanium surface: static charge generation

Recent advances in biomaterials’ research suggest that electrical charges on a dental implant surface significantly improve its osseointegration to living bone, as a result of selective osteoblast activation and fibroblast inhibition. This study aims at investigating the possibility of using sandblasting to modify the electrical charges on the surface of titanium materials. Our experiments used Al₂O₃ grits to blast on CP2 titanium plates, for durations between 3 and 30?s. After sandblasting, Ti surfaces were measured for their electrostatic voltage. The results indicate a novel finding, i.e. negative static charges are generated on the titanium surface, which may stimulate osteoblast activity to promote osseointegration around dental implant surface. This finding may at least partially explain the good osseointegration results of sandblasted titanium dental implants, in addition to other known reasons, such as topological changes on the implant’s surface. However, the static charges accumulated on the titanium surface during sandblasting decayed to a lower level with time. It remains a challenging task to seek ways to retain these charges after quantification of desired level of negative charges needed to promote osteoblast activity for osseointegration around dental implants.     

Unpatterned Bioactive Poly(Butylene 1,4-Cyclohexanedicarboxylate)-Based Film Fast Induced Neuronal-Like Differentiation of Human Bone Marrow-Mesenchymal Stem Cells

Herein, we present poly(butylene 1,4-cyclohexanedicarboxylate) (PBCE) films characterized by an unpatterned microstructure and a specific hydrophobicity, capable of boosting a drastic cytoskeleton architecture remodeling, culminating with the neuronal-like differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs). We have used two different filming procedures to prepare the films, solvent casting (PBCE) and compression-moulding (PBCE*). PBCE film had a rough and porous surface with spherulite-like aggregations (Ø = 10–20 μm) and was characterized by a water contact angle = 100°. PBCE* showed a smooth and continuous surface without voids and visible spherulite-like aggregations and was more hydrophobic (WCA = 110°). Both surface characteristics were modulated through the copolymerization of different amounts of ether-oxygen-containing co-units into PBCE chemical structure. We showed that only the surface characteristics of PBCE-solvent-casted films steered hBM-MSCs toward a neuronal-like differentiation. hBM-MSCs lost their canonical mesenchymal morphology, acquired a neuronal polarized shape with a long cell protrusion (≥150 μm), expressed neuron-specific class III β-tubulin and microtubule-associated protein 2 neuronal markers, while nestin, a marker of uncommitted stem cells, was drastically silenced. These events were observed as early as 2-days after cell seeding. Of note, the phenomenon was totally absent on PBCE* film, as hBM-MSCs maintained the mesenchymal shape and behavior and did not express neuronal/glial markers.     

New O- and N-N-Bridging Complexes of Tc(V), the Role of the Nitrogen Atom Position in Aromatic Rings: Reaction Mechanism,Spectroscopy, DTA,XRD and Hirshfeld Surface Analysis

In this work, O- and N-N-bridging complexes of technetium (V), previously known only for rhenium, were obtained for the first time. Tc(V) complexes with pyridazine (pyd), 1,2,4-triazole (trz), 3,5-dimethylpyrazole (dmpz) and pyrimidine (pyr) were obtained. In three complexes [{TcOCl₂}₂(μ-O)(μ-pyd)₂], [{TcOCl₂}₂(μ-O)(μ-trz)₂]·Htrz·Cl and [{TcO(dmpz)₄}(μ-O)(TcOCl₄)] two technetium atoms are linked by a Tc-O-Tc bond, and in the first two, Tc atoms are additionally linked by a Tc-N-N-Tc bond through the nitrogen atoms of the aromatic rings. We determined the role of nitrogen atom position in the aromatic ring and the presence of substituents on the formation of such complexes. For the first time, a reaction mechanism for the formation of such complexes was proposed. This article details the crystal structures of four new compounds. The work describes in detail the coordination of Tc atoms in the obtained structures and the regularities of the formation of crystal packings. The spectroscopic properties of the obtained compounds and their mother solutions were studied. The decomposition temperatures of the described complexes were determined. An assumption was made about the oligomerization of three-bridged complexes based on the results of mass spectrometry. Through the analysis of non-valent interactions in the structures, π-stacking, halogen-π and CH-π interactions were found. An analysis of the Hirshfeld surface for [{TcOCl₂}₂(μ-O)(μ-pyd)₂], [{TcOCl2}2(μ-O)(μ-trz)₂] and their rhenium analogues showed that the main contribution to the crystalline packing is made by interactions of the type Hal···H/H···Hal (45.4–48.9%), H···H (10.2–15.8%), and O···H/H···O (9.4–16.5%).     

The Effect of Pore Size Distribution and l-Lysine Modified Apatite Whiskers (HAP) on Osteoblasts Response in PLLA/HAP Foam Scaffolds Obtained in the Thermally Induced Phase Separation Process

In this research, we prepared foam scaffolds based on poly(l-lactide) (PLLA) and apatite whiskers (HAP) using thermally induced phase separation technique supported by the salt leaching process (TIPS-SL). Using sodium chloride having a size of (a) 150–315 μm, (b) 315–400 μm, and (c) 500–600 μm, three types of foams with different pore sizes have been obtained. Internal structure of the obtained materials has been investigated using SEM as well as μCT. The materials have been studied by means of porosity, density, and compression tests. As the most promising, the composite prepared with salt size of 500–600 μm was prepared also with the l-lysine modified apatite. The osteoblast hFOB 1.19 cell response for the scaffolds was also investigated by means of cell viability, proliferation, adhesion/penetration, and biomineralization. Direct contact cytotoxicity assay showed the cytocompatibility of the scaffolds. All types of foam scaffolds containing HAP whiskers, regardless the pore size or l-lysine modification induced significant stimulatory effect on the cal-cium deposits formation in osteoblasts. The PLLA/HAP scaffolds modified with l-lysine stimulated hFOB 1.19 osteoblasts proliferation. Compared to the scaffolds with smaller pores (150–315 µm and 315–400 µm), the PLLA/HAP foams with large pores (500–600 µm) promoted more effective ad-hesion of osteoblasts to the surface of the biomaterial.     

Hierarchically Structured Polystyrene-Based Surfaces Amplifying Fluorescence Signals: Cytocompatibility with Human Induced Pluripotent Stem Cell

An innovative multi-step phase separation process was used to prepare tissue culture for the polystyrene-based, hierarchically structured substrates, which mimicked in vivo microenvironment and architecture. Macro- (pore area from 3000 to 18,000 µm²; roughness (Ra) 7.2 ± 0.1 µm) and meso- (pore area from 50 to 300 µm²; Ra 1.1 ± 0.1 µm) structured substrates covered with micro-pores (area around 3 µm²) were prepared and characterised. Both types of substrate were suitable for human-induced pluripotent stem cell (hiPSC) cultivation and were found to be beneficial for the induction of cardiomyogenesis in hiPSC. This was confirmed both by the number of promoted proliferated cells and the expressions of specific markers (Nkx2.5, MYH6, MYL2, and MYL7). Moreover, the substrates amplified the fluorescence signal when Ca²⁺ flow was monitored. This property, together with cytocompatibility, make this material especially suitable for in vitro studies of cell/material interactions within tissue-mimicking environments.     

Early Bone Healing on Hydroxyapatite-Coated and Chemically-Modified Hydrophilic Implant Surfaces in an Ovine Model

Implant topography affects early peri-implant bone healing by changing the osteoconduction rate in the surrounding biological environment. Implant surfaces have been designed to promote faster and stronger bone formation for rapid and stable prosthesis loading. Early peri-implant bone healing has been observed with a sandblasted, acid-etched implant that was chemically modified to be hydrophilic (cmSLA). The present study investigates whether early peri-implant bone healing extends to a rough surface implant with a high crystalline hydroxyapatite surface (TSV MP-1 HA). Three implants were randomly placed in porous trabecular bone within both medial femoral condyles of 10 sheep. Early peri-implant bone stability was measured at 3- and 6-weeks healing time following implant insertion. Results indicated a similar implant stability quotient between the implants at insertion and over time. The significant increase over time of reverse torque values with respect to insertion torque (p < 0.001) did not differ between the implants. However, the bone-to-implant contact of TSV MP-1 HA was significantly higher than that of cmSLA implants at 6 weeks (p < 0.01). These data validate previous findings of a hydrophilic implant surface and extend the observation of early osseointegration to a rough surface implant in porous trabecular bone.     

Use of CGF in Oral and Implant Surgery: From Laboratory Evidence to Clinical Evaluation

Edentulism is the condition of having lost natural teeth, and has serious social, psychological, and emotional consequences. The need for implant services in edentulous patients has dramatically increased during the last decades. In this study, the effects of concentrated growth factor (CGF), an autologous blood-derived biomaterial, in improving the process of osseointegration of dental implants have been evaluated. Here, permeation of dental implants with CGF has been obtained by using a Round up device. These CGF-coated dental implants retained a complex internal structure capable of releasing growth factors (VEGF, TGF-β1, and BMP-2) and matrix metalloproteinases (MMP-2 and MMP-9) over time. The CGF-permeated implants induced the osteogenic differentiation of human bone marrow stem cells (hBMSC) as confirmed by matrix mineralization and the expression of osteogenic differentiation markers. Moreover, CGF provided dental implants with a biocompatible and biologically active surface that significantly improved adhesion of endothelial cells on CGF-coated implants compared to control implants (without CGF). Finally, data obtained from surgical interventions with CGF-permeated dental implants presented better results in terms of optimal osseointegration and reduced post-surgical complications. These data, taken together, highlight new and interesting perspectives in the use of CGF in the dental implantology field to improve osseointegration and promote the healing process.     

Supercritical Carbon Dioxide and Microwave-Assisted Extraction of Functional Lipophilic Compounds from Arthrospira platensis

Arthrospira platensis biomass was used in order to obtain functional lipophilic compounds through green extraction technologies such as supercritical carbon dioxide fluid extraction (SFE) and microwave-assisted extraction (MAE). The temperature (T) factor was evaluated for MAE, while for SFE, pressure (P), temperature (T), and co-solvent (ethanol) (CS) were evaluated. The maximum extraction yield of the obtained oleoresin was (4.07% ± 0.14%) and (4.27% ± 0.10%) for SFE and MAE, respectively. Extracts were characterized by gas chromatography mass spectrometry (GC-MS) and gas chromatography flame ionization detector (GC-FID). The maximum contents of functional lipophilic compounds in the SFE and MAE extracts were: for carotenoids 283 ± 0.10 μg/g and 629 ± 0.13 μg/g, respectively; for tocopherols 5.01 ± 0.05 μg/g and 2.46 ± 0.09 μg/g, respectively; and for fatty acids 34.76 ± 0.08 mg/g and 15.88 ± 0.06 mg/g, respectively. In conclusion, the SFE process at P 450 bar, T 60 °C and CS 53.33% of CO₂ produced the highest yield of tocopherols, carotenoids and fatty acids. The MAE process at 400 W and 50 °C gives the best extracts in terms of tocopherols and carotenoids. For yield and fatty acids, the MAE process at 400 W and 70 °C produced the highest values. Both SFE and MAE showed to be suitable green extraction technologies for obtaining functional lipophilic compounds from Arthrospira platensis.     

First Experimental Study of the Influence of Extracellular Vesicles Derived from Multipotent Stromal Cells on Osseointegration of Dental Implants

Herein, the aim was to study the state of the bone tissue adjacent to dental implants after the use of extracellular vesicles derived from multipotent stromal cells (MSC EVs) of bone marrow origin in the experiment. In compliance with the rules of asepsis and antiseptics under general intravenous anesthesia with propofol, the screw dental implants were installed in the proximal condyles of the tibia of outbred rabbits without and with preliminary introduction of 19.2 μg MSC EVs into each bone tissue defect. In 3, 7, and 10 days after the operation, the density of bone tissue adjacent to different parts of the implant using an X-ray unit with densitometer was measured. In addition, the histological examinations of the bone site with the hole from the removed device and the soft tissues from the surface of the proximal tibial condyle in the area of intra-bone implants were made. It was found out that 3 days after implantation with the use of MSC EVs, the bone density was statistically significantly higher by 47.2% than after the same implantation, but without the injection of MSC EVs. It is possible that as a result of the immunomodulatory action of MSC EVs, the activity of inflammation decreases, and, respectively, the degree of vasodilation in bones and leukocyte infiltration of the soft tissues are lower, in comparison with the surgery performed in the control group. The bone fragments formed during implantation are mainly consolidated with each other and with the regenerating bone. Day 10 demonstrated that all animals with the use of MSC EVs had almost complete fusion of the screw device with the bone tissue, whereas after the operation without the application of MSC EVs, the heterogeneous histologic pattern was observed: From almost complete osseointegration of the implant to the absolute absence of contact between the foreign body and the new formed bone. Therefore, the use of MSC EVs during the introduction of dental implants into the proximal condyle of the tibia of rabbits contributes to an increase of the bone tissue density near the device after 3 days and to the achievement of consistently successful osseointegration of implants 10 days after the surgery.     

Structural Design and Finite Element Simulation Analysis of Grade 3 Graded Porous Titanium Implant

The metal titanium is often used as a dental implant material, and the elastic modulus of solid titanium implants does not match the biological bone tissue, which can easily produce a stress shielding effect and cause implant failure. In this paper, a three-level gradient porous structure implant was designed, and its mechanical and biological adaptability were studied by finite element simulation analysis. Combined with the comprehensive evaluation of the mechanical and biological properties of implants of various structures, the analysis found that a porous implant with porosity of 59.86% of the gradient was the best structure. The maximum equivalent stress of this structure in the mandible that simulated the oral environment was 154.34 MPa, which was less than half of its theoretical compression yield strength. The strain of the surrounding bone tissue lies in the bone compared with other structures, the proportion of the active state of plastic construction is larger, at 10.51%, and the fretting value of this structure and the bone tissue interface is the smallest, at only 10 μm.     

Biomimetic Zirconia with Cactus-Inspired Meso-Scale Spikes and Nano-Trabeculae for Enhanced Bone Integration

Biomimetic design provides novel opportunities for enhancing and functionalizing biomaterials. Here we created a zirconia surface with cactus-inspired meso-scale spikes and bone-inspired nano-scale trabecular architecture and examined its biological activity in bone generation and integration. Crisscrossing laser etching successfully engraved 60 μm wide, cactus-inspired spikes on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) with 200–300 nm trabecular bone-inspired interwoven structures on the entire surface. The height of the spikes was varied from 20 to 80 μm for optimization. Average roughness (Sa) increased from 0.10 μm (polished smooth surface) to 18.14 μm (80 μm-high spikes), while the surface area increased by up to 4.43 times. The measured dimensions of the spikes almost perfectly correlated with their estimated dimensions (R² = 0.998). The dimensional error of forming the architecture was 1% as a coefficient of variation. Bone marrow-derived osteoblasts were cultured on a polished surface and on meso- and nano-scale hybrid textured surfaces with different spike heights. The osteoblastic differentiation was significantly promoted on the hybrid-textured surfaces compared with the polished surface, and among them the hybrid-textured surface with 40 μm-high spikes showed unparalleled performance. In vivo bone-implant integration also peaked when the hybrid-textured surface had 40 μm-high spikes. The relationships between the spike height and measures of osteoblast differentiation and the strength of bone and implant integration were non-linear. The controllable creation of meso- and nano-scale hybrid biomimetic surfaces established in this study may provide a novel technological platform and design strategy for future development of biomaterial surfaces to improve bone integration and regeneration.     

Cryogenic 3D Printing of w/o Pickering Emulsions Containing Bifunctional Drugs for Producing Hierarchically Porous Bone Tissue Engineering Scaffolds with Antibacterial Capability

How to fabricate bone tissue engineering scaffolds with excellent antibacterial and bone regeneration ability has attracted increasing attention. Herein, we produced a hierarchical porous β-tricalcium phosphate (β-TCP)/poly(lactic-co-glycolic acid)-polycaprolactone composite bone tissue engineering scaffold containing tetracycline hydrochloride (TCH) through a micro-extrusion-based cryogenic 3D printing of Pickering emulsion inks, in which the hydrophobic silica (h-SiO₂) nanoparticles were used as emulsifiers to stabilize composite Pickering emulsion inks. Hierarchically porous scaffolds with desirable antibacterial properties and bone-forming ability were obtained. Grid scaffolds with a macroscopic pore size of 250.03 ± 75.88 μm and a large number of secondary micropores with a diameter of 24.70 ± 15.56 μm can be fabricated through cryogenic 3D printing, followed by freeze-drying treatment, whereas the grid structure of scaffolds printed or dried at room temperature was discontinuous, and fewer micropores could be observed on the strut surface. Moreover, the impartment of β-TCP in scaffolds changed the shape and density of the micropores but endowed the scaffold with better osteoconductivity. Scaffolds loaded with TCH had excellent antibacterial properties and could effectively promote the adhesion, expansion, proliferation, and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells afterward. The scaffolds loaded with TCH could realize the strategy to “kill bacteria first, then induce osteogenesis”. Such hierarchically porous scaffolds with abundant micropores, excellent antibacterial property, and improved bone-forming ability display great prospects in treating bone defects with infection.     

The Potential of Calcium/Phosphate Containing MAO Implanted in Bone Tissue Regeneration and Biological Characteristics

Micro arc oxidation (MAO) is a prominent surface treatment to form bioceramic coating layers with beneficial physical, chemical, and biological properties on the metal substrates for biomaterial applications. In this study, MAO treatment has been performed to modify the surface characteristics of AZ31 Mg alloy to enhance the biocompatibility and corrosion resistance for implant applications by using an electrolytic mixture of Ca₃(PO₄)₂ and C₁₀H₁₆N₂O₈ (EDTA) in the solutions. For this purpose, the calcium phosphate (Ca-P) containing thin film was successfully fabricated on the surface of the implant material. After in-vivo implantation into the rabbit bone for four weeks, the apparent growth of soft tissues and bone healing effects have been documented. The morphology, microstructure, chemical composition, and phase structures of the coating were identified by SEM, XPS, and XRD. The corrosion resistance of the coating was analyzed by polarization and salt spray test. The coatings consist of Ca-P compounds continuously have proliferation activity and show better corrosion resistance and lower roughness in comparison to mere MAO coated AZ31. The corrosion current density decreased to approximately 2.81 × 10⁻⁷ A/cm² and roughness was reduced to 0.622 μm. Thus, based on the results, it was anticipated that the development of degradable materials and implants would be feasible using this method. This study aims to fabricate MAO coatings for orthopedic magnesium implants that can enhance bioactivity, biocompatibility, and prevent additional surgery and implant-related infections to be used in clinical applications.     

Chemical and magnetic functionalization of graphene oxide as a route to enhance its biocompatibility

The novel approach for deposition of iron oxide nanoparticles with narrow size distribution supported on different sized graphene oxide was reported. Two different samples with different size distributions of graphene oxide (0.5 to 7 μm and 1 to 3 μm) were selectively prepared, and the influence of the flake size distribution on the mitochondrial activity of L929 with WST1 assay in vitro study was also evaluated. Little reduction of mitochondrial activity of the GO-Fe₃O₄ samples with broader size distribution (0.5 to 7 μm) was observed. The pristine GO samples (0.5 to 7 μm) in the highest concentrations reduced the mitochondrial activity significantly. For GO-Fe₃O₄ samples with narrower size distribution, the best biocompatibility was noticed at concentration 12.5 μg/mL. The highest reduction of cell viability was noted at a dose 100 μg/mL for GO (1 to 3 μm). It is worth noting that the chemical functionalization of GO and Fe₃O₄ is a way to enhance the biocompatibility and makes the system independent of the size distribution of graphene oxide.     

On Interlayer Stability and High-Cycle Simulator Performance of Diamond-Like Carbon Layers for Articulating Joint Replacements

Diamond like carbon (DLC) coatings have been proven to be an excellent choice for wear reduction in many technical applications. However, for successful adaption to the orthopaedic field, layer performance, stability and adhesion in physiologically relevant setups are crucial and not consistently investigated. In vitro wear testing as well as adequate corrosion tests of interfaces and interlayers are of great importance to verify the long term stability of DLC coated load bearing implants in the human body. DLC coatings were deposited on articulating lumbar spinal disks made of CoCr28Mo6 biomedical implant alloy using a plasma-activated chemical vapor deposition (PACVD) process. As an adhesion promoting interlayer, tantalum films were deposited by magnetron sputtering. Wear tests of coated and uncoated implants were performed in physiological solution up to a maximum of 101 million articulation cycles with an amplitude of ±2° and −3/+6° in successive intervals at a preload of 1200 N. The implants were characterized by gravimetry, inductively coupled plasma optical emission spectrometry (ICP-OES) and cross section scanning electron microscopy (SEM) analysis. It is shown that DLC coated surfaces with uncontaminated tantalum interlayers perform very well and no corrosive or mechanical failure could be observed. This also holds true in tests featuring overload and third-body wear by cortical bone chips present in the bearing pairs. Regarding the interlayer tolerance towards interlayer contamination (oxygen), limits for initiation of potential failure modes were established. It was found that mechanical failure is the most critical aspect and this mode is hypothetically linked to the α-β tantalum phase switch induced by increasing oxygen levels as observed by X-ray diffraction (XRD). It is concluded that DLC coatings are a feasible candidate for near zero wear articulations on implants, potentially even surpassing the performance of ceramic vs. ceramic.