Osteoblast cell adhesion on a laser modified zirconia based bioceramic

Antibacterial Zirconia Surfaces from Organocatalyzed Atom-Transfer Radical Polymerization

Antibacterial coatings are becoming increasingly attractive for application in the field of biomaterials. In this framework, we developed polymer coating zirconia with antibacterial activity using the "grafting from" methodology. First, 1-(4-vinylbenzyl)-3-butylimidazolium chloride monomer was synthesized. Then, the surface modification of zirconia substrates was performed with this monomer via surface-initiated photo atom transfer radical polymerization for antibacterial activity. X-ray photoelectron spectroscopy, ellipsometry, static contact angle measurements, and an atomic force microscope were used to characterize the films for each step of the surface modification. The results revealed that cationic polymers could be successfully deposited on the zirconia surfaces, and the thickness of the grafted layer steadily increased with polymerization time. Finally, the antibacterial adhesion test was used to evaluate the antibacterial activity of the modified zirconia substrates, and we successfully showed the antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains.

Influence of laser intensity and BaTiO3 content on the surface properties of 3YSZ

Zirconia-based dental implants are in direct contact with living tissues and any improvements in their bioactivity and adhesion to the tissues are highly welcome. In this study, different ratios of barium titanate (BT) were added to 3 mol% yttria-stabilized zirconia (3YSZ) through conventional sintering. The laser-texturing technique was also conducted to improve the biological performance of 3YSZ ceramics. The composition and the surface of the prepared composites were characterized by X-ray diffraction and scanning electron microscopy (SEM), respectively. The roughness and surface wettability of the composites were also measured. Furthermore, MC3T3-E1 pre-osteoblast cells were used for the in vitro experiments. Cell viability was evaluated using a commercial resazurin-based method. Morphology and cellular adhesion were observed using SEM. Based on the results, the laser texturing and the barium titanate content influenced the surface characteristics of the prepared composites. The laser-textured 3YSZ/7 mol% BT composites showed a lower water contact angle compared to the other samples, which indicated superior surface hydrophilicity. The cell viability and cell adhesion of 3YSZ/BT composites increased with the rise in the barium titanate content and laser power. An elongated cell morphology and apatite nucleation were also observed by the BT content. Overall, the laser-treated 3YSZ/5 and 7 mol% BT composites may be promising candidates in hard tissue repair due to their good cell response.

Role and Mechanism of a Micro-/Nano-Structured Porous Zirconia Surface in Regulating the Biological Behavior of Bone Marrow Mesenchymal Stem Cells

Zirconia as a promising dental implant material has attracted much attention in recent years. Improving the bone binding ability of zirconia is critical for clinical applications. Here, we established a distinct micro-/nano-structured porous zirconia through dry-pressing with addition of pore-forming agents followed by hydrofluoric acid etching (POROHF). Porous zirconia without hydrofluoric acid treatment (PORO), sandblasting plus acid-etching zirconia, and sintering zirconia surface were applied as controls. After human bone marrow mesenchymal stem cells (hBMSCs) were seeded on these four groups of zirconia specimens, we observed the highest cell affinity and extension on POROHF. In addition, the POROHF surface displayed an improved osteogenic phenotype in contrast to the other groups. Moreover, the POROHF surface facilitated angiogenesis of hBMSCs, as confirmed by optimal stimulation of vascular endothelial growth factor B and angiopoietin 1 (ANGPT1) expression. Most importantly, the POROHF group demonstrated the most obvious bone matrix development in vivo. To investigate further the underlying mechanism, RNA sequencing was employed and critical target genes modulated by POROHF were identified. Taken together, this study established an innovative micro-/nano-structured porous zirconia surface that significantly promoted osteogenesis and investigated the potential underlying mechanism. Our present work will improve the osseointegration of zirconia implants and help further clinical applications.

Superhydrophilic and topography-regulatable surface grafting on PEEK to improve cellular affinity

Polyetheretherketone (PEEK) has been widely used in the preparation of orthopedic implants due to its biological inertness and similar mechanical modulus to natural bone. However, the affinity between biological tissue (bone and soft tissue) and PEEK surface is weak, leading to low osseointegration and an increased risk of inflammation. The situation could be improved by modifying PEEK surface. Surfaces with good hydrophilicity and proper microtopography would promote cellular adhesion and proliferation. This work presented a two-step surface modification method to achieve the effect. Polyacrylic acid (PAA) chains were grafted on PEEK surface by UV irradiation. Then, ethylenediamine (EDA) was added to introduce amino groups and promote the cross-linking of PAA chains. Furthermore, a mathematical model was built to describe and regulate the surface topography growth process semi-quantitatively. The model fits experimental data quite well (adjusted R² = 0.779). Results showed that the modified PEEK surface obtained superhydrophilicity. It significantly improved the adhesion and proliferation of BMSCs and MFBs by activating the FAK pathway and Rho family GTPase. The cellular affinity performed better when the surface topography was in network structure with holes in about 25 μm depth and 20-50 μm diameter. Good hydrophilicity seems necessary for the FAK pathway activation, but simply improving surface hydrophilicity might not be enough for cellular affinity improvement. Surface topography at micron scale should be a more important cue. This simple surface modification method could be contributed to further study of cell-microtopography interaction and have potential applications in clinical PEEK orthopedic implants.

Advancing dental implants: Bioactive and therapeutic modifications of zirconia

Zirconium-based implants have gained popularity in the dental implant field owing to their corrosion resistance and biocompatibility, attributed to the formation of a native zirconia (ZrO₂) film. However, enhanced bioactivity and local therapy from such implants are desirable to enable the earlier establishment and improved long-term maintenance of implant integration, especially in compromised patient conditions. As a result, surface modification of zirconium-based implants have been performed using various physical, chemical and biological techniques at the macro-, micro-, and nano-scales. In this extensive review, we discuss and detail the development of Zr implants covering the spectrum from past and present advancements to future perspectives, arriving at the next generation of highly bioactive and therapeutic nano-engineered Zr-based implants. The review provides in-depth knowledge of the bioactive/therapeutic value of surface modification of Zr implants in dental implant applications focusing on clinical translation.

Modification of Zirconia Implant Surfaces by Nd:YAG Laser Grooves: Does It Change Cell Behavior?

The aim of this study was to evaluate gingival fibroblasts and human osteoblasts’ response to textured Nd:YAG laser microgrooves, with different dimensions, on zirconia implant surfaces. A total of 60 zirconia disks (8 mm in diameter and 2 mm in thickness) were produced and divided between four study groups (N = 15): three laser-textured (widths between 125.07 ± 5.29 μm and 45.36 ± 2.37 μm and depth values from 50.54 ± 2.48 μm to 23.01 ± 3.79 μm) and a control group without laser treatment. Human osteoblasts and gingival fibroblasts were cultured on these surfaces for 14 days. FEG-SEM (Field Emission Gun–Scanning Electron Microscope) images showed cellular adhesion at 24 h, with comparable morphology in all samples for both cell types. A similar cell spreading within the grooves and in the space between them was observed. Cell viability increased over time in all study groups; however, no differences were found between them. Additionally, proliferation, ALP (Alkaline phosphatase) activity, collagen type I, osteopontin and interleukin levels were not significantly different between any of the study groups for any of the cell types. Analysis of variance to compare parameters effect did not reveal statistically significant differences when comparing all groups in the different tests performed. The results obtained revealed similar cell behavior based on cell viability and differentiation on different microtopographic laser grooves, compared to a microtopography only established by sandblasting and acid-etching protocol, the reference surface treatment on zirconia dental implants.

Surface modification of zirconia dental implants by laser texturing

The aim of this work was to perform an integrative literature review on the influence of laser irradiation on zirconia implants to enhance surface topographic aspects and the biological response for osseointegration. An electronic search was carried out on the PubMed database using the following search terms: "zirconia" AND "laser" AND "surface modification" OR "surface treatment" AND "dental implants" OR "bone" OR "osteoblast" OR "osseointegration." Of the identified articles, 12 studies were selected in this review. Results reported that the laser irradiation was capable of promoting changes on the zirconia surfaces regarding topographic aspects, roughness, and wettability. An increase in roughness was recorded at micro- and nano-scale and it resulted in an enhanced wettability and biological response. Also, adhesion, spreading, proliferation, and differentiation of osteogenic cells were also enhanced after laser irradiation mainly by using a femtosecond laser at 10nJ and 80 MHz. After 3 months of osseointegration, in vivo studies in dogs revealed a similar average percentage of bone-to-implant contact (BIC) on zirconia surfaces (around 47.9 ± 16%) when compared to standard titanium surfaces (61.73 ±16.27%), denoting that there is no significant difference between such different materials. The laser  approach revealed several parameters that can be used for zirconia surface modification such as irradiation intensity, time, and frequency. Laser irradiation parameters can be optimized and well-controlled to reach desirable surface morphologic aspects and biological response concerning the osseointegration process.

Classification and Properties of Dental Zirconia as Implant Fixtures and Superstructures

Various types of zirconia are widely used for the fabrication of dental implant superstructures and fixtures. Zirconia-alumina composites, such as ATZ and NanoZR, are adequate for implant fixtures because they have excellent mechanical strength in spite of insufficient esthetic properties. On the other hand, yttria-stabilized zirconia has been used for implant superstructures because of sufficient esthetic properties. They are classified to 12 types with yttria content, monochromatic/polychromatic, uniform/hybrid composition, and monolayer/multilayer. Zirconia with a higher yttria content has higher translucency and lower mechanical strength. Fracture strength of superstructures strongly depends on the strength on the occlusal contact region. It suggests that adequate zirconia should be selected as the superstructure crown, depending on whether strength or esthetics is prioritized. Low temperature degradation of zirconia decreases with yttria content, but even 3Y zirconia has a sufficient durability in oral condition. Although zirconia is the hardest dental materials, zirconia restorative rarely subjects the antagonist teeth to occlusal wear when it is mirror polished. Furthermore, zirconia has less bacterial adhesion and better soft tissue adhesion when it is mirror polished. This indicates that zirconia has advantageous for implant superstructures. As implant fixtures, zirconia is required for surface modification to obtain osseointegration to bone. Various surface treatments, such as roughening, surface activation, and coating, has been developed and improved. It is concluded that an adequately selected zirconia is a suitable material as implant superstructures and fixtures because of mechanically, esthetically, and biologically excellent properties.

Zirconia Materials for Dental Implants: A Literature Review

Titanium is currently the most commonly used material for manufacturing dental implants. However, its potential toxic effects and the gray color have resulted in increasing requests for metal-free treatment options. Zirconia is a type of ceramic materials that has been extensively used in medicine field, such as implant abutments and various joint replacement appliances. Amounts of clinical evaluations have indicated good biocompatibility for zirconia products. Besides, its toothlike color, low affinity for plaque and outstanding mechanical and chemical properties have made it an ideal candidate for dental implants. The aim of this study is to review the laboratory and clinical papers about several kinds of zirconia materials and zirconia surface modification techniques. Although there are plenty of literatures on these topics, most of the researches focused on the mechanical properties of the materials or based on cell and animal experiments. Randomized clinical trials on zirconia materials are still urgently needed to validate their application as dental implants.

Laser surface treatment on Yttria-stabilized zirconia dental implants: Influence on cell behavior

Yttria-stabilized zirconia (YSZ) is being proposed as an alternative material to Titanium for dental implants due to its aesthetic and biocompatibility properties. However, is it yet to define the optimal surface treatment to improve YSZ bioactivy. Texturization is a promising approach, but the biological role of patterned YSZ surfaces in cell cultures is yet to be determined. Thus, cellular behavior of osteoblasts and fibroblasts in contact with groove-texturized YSZ surfaces was investigated. YSZ discs were groove-textured by conventional milling and Nd:YAG laser. All samples including control were sandblasted and acid-etched. Human osteoblasts and fibroblasts were cultured on discs for 14 days. Morphology and cellular adhesion were observed. Cell viability, interleukin-1β, osteopontin, collagen type I prodution, alkaline phosphatase activity, and interleukin-8 were measured. YSZ texturization by conventional milling improved osteoblasts viability and differentiation when compared to laser texturization. Fibroblasts behavior did not seem to be influenced by the texturing technique. Compared to sandblasting and acid etching currently used as gold standard for zirconia dental implants no superiority of macrotexturization was found.

Surface Finishing of Zirconium Dioxide with Abrasive Brushing Tools

Brushing with bonded abrasives is a finishing process which can be used for the surface improvement of various materials. Since the machining mechanisms of abrasive brushing processes are still largely unknown and little predating research was done on brushing ceramic workpieces, within the scope of this work technological investigations were carried out on planar workpieces of MgO-PSZ (zirconium dioxide, ZrO2) using brushing tools with bonded grains of polycrystalline diamond. The primary goal was the reduction of grinding-related surface defects under the preservation of surface roughness valleys and workpiece form. Based on microscopy and topography measurements, the grain size sg and the brushing velocity vb were found to have a considerable influence on the processing result. Furthermore, excessive tool wear was observed while brushing ceramics.

Bioinstructive Micro-Nanotextured Zirconia Ceramic Interfaces for Guiding and Stimulating an Osteogenic Response In Vitro

Osseous implantology’s material requirements include a lack of potential for inducing allergic disorders and providing both functional and esthetic features for the patient’s benefit. Despite being bioinert, Zirconia ceramics have become a candidate of interest to be used as an alternative to titanium dental and cochlear bone-anchored hearing aid (BAHA) implants, implying the need for endowing the surface with biologically instructive properties by changing basic parameters such as surface texture. Within this context, we propose anisotropic and isotropic patterns (linear microgroove arrays, and superimposed crossline microgroove arrays, respectively) textured in zirconia substrates, as bioinstructive interfaces to guide the cytoskeletal organization of human mesenchymal stem cells (hMSCs). The designed textured micro-nano interfaces with either steep ridges and microgratings or curved edges, and nanoroughened walls obtained by direct femtosecond laser texturing are used to evaluate the hMSC response parameters and osteogenic differentiation to each topography. Our results show parallel micro line anisotropic surfaces are able to guide cell growth only for the steep surfaces, while the curved ones reduce the initial response and show the lowest osteogenic response. An improved osteogenic phenotype of hMSCs is obtained when grown onto isotropic grid/pillar-like patterns, showing an improved cell coverage and Ca/P ratio, with direct implications for BAHA prosthetic development, or other future applications in regenerating bone defects.

Surface Modified Techniques and Emerging Functional Coating of Dental Implants

Dental implants are widely used in the field of oral restoration, but there are still problems leading to implant failures in clinical application, such as failed osseointegration, marginal bone resorption, and peri-implantitis, which restrict the success rate of dental implants and patient satisfaction. Poor osseointegration and bacterial infection are the most essential reasons resulting in implant failure. To improve the clinical outcomes of implants, many scholars devoted to modifying the surface of implants, especially to preparing different physical and chemical modifications to improve the osseointegration between alveolar bone and implant surface. Besides, the bioactive-coatings to promote the adhesion and colonization of ossteointegration-related proteins and cells also aim to improve the osseointegration. Meanwhile, improving the anti-bacterial performance of the implant surface can obstruct the adhesion and activity of bacteria, avoiding the occurrence of inflammation related to implants. Therefore, this review comprehensively investigates and summarizes the modifying or coating methods of implant surfaces, and analyzes the ossteointegration ability and anti-bacterial characteristics of emerging functional coatings in published references.

An introduction of biological performance of zirconia with different surface characteristics: A review

Zirconia (ZrO₂) ceramic is widely used in dentistry as a clinical dental biomaterial. In this review, we are focusing on and summarizing the biological performance of zirconia under different surface characteristics. We have included an initial tissue cell attachment study on zirconia and bacterial adhesion on zirconia. Our results suggest that surface modifications applied on zirconia may change the interfacial surface characteristics e.g. surface roughness, surface free energy, and chemistry of zirconia. The modifications also result in advanced biological performance of zirconia, including enhanced tissue cell attachment and reduction of bacterial adhesion. The recent laboratory research has provided many interesting modification methods and showed clinically interesting and promising outcomes. A few of the outcomes are validated and have been applied in clinical dentistry.

Effect of the Compositions on the Biocompatibility of New Alumina-Zirconia-Titania Dental Ceramic Composites

Dental implant biomaterials are expected to be in contact with living tissues, therefore their toxicity and osseointegration ability must be carefully assessed. In the current study, the wettability, cytotoxicity, and genotoxicity of different alumina-zirconia-titania composites were evaluated. The surface wettability determines the biological event cascade in the bioceramic/human living tissues interface. The measured water contact angle indicated that the wettability strongly depends on the ceramic composition. Notwithstanding the contact angle variability, the ceramic surfaces are hydrophilic. The cytotoxicity of human gingival fibroblast cells with materials, evaluated by an (3-(4,5 methylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) test, revealed an absence of any cytotoxic effect. A relationship was found between the cell viability and the wettability. It was subsequently deduced that the cell viability increases when the wettability increases. This effect is more pronounced when the titania content is higher. Finally, a comet test was applied as complementary biocompatibility test to detect any changes in fibroblast cell DNA. The results showed that the DNA damage is intimately related to the TiO₂ content. Genotoxicity was mainly attributed to ceramic composites containing 10 wt.% TiO₂. Our research revealed that the newly developed high performance alumina-zirconia-titania ceramic composites contain less than 10 wt.% TiO₂, and display promising surface properties, making them suitable for dental implantology applications.

Novel laser textured surface designs for improved zirconia implants performance

The development of new surface designs to enhance the integration process between surgically placed implants and biological tissues remains a challenge for the scientific community. In this way and trying to overcome this issue, in this work, laser technology was explored to produce novel textures on the surface of green zirconia compacts produced by cold pressing technique. Two strategies regarding line design (8 and 16 lines design) and different laser parameters (laser power and number of laser passages) were explored to assess their influence on geometry and depth of created textures. The produced textures were evaluated with Scanning Electron Microscopy (SEM) and it was observed that well-defined textured surfaces with regular geometric features (cavities or pillars) were obtained by laser combining different strategies lines design and parameters. The potential of proposed textures was also evaluated regarding surface wettability, friction performance (static and dynamic coefficient of friction evolution) against bone, aging resistance and flexural strength. Results demonstrated that all the produced textures display a super hydrophilic or hydrophilic behavior. Regarding the friction behavior, it was experimentally observed a high initial static coefficient of friction (COF) for all produced textures. Concerning the aging resistance, all the textured surfaces revealed a low monoclinic content, less than 25% after 5 h of hydrothermal aging. The flexural strength results showed that the mechanical resistance of zirconia was not significantly compromised with the laser action. Based on the obtained results, it is possible to prove that the processing route used for manufacturing the new and different surface designs (cold pressing technique followed by laser texturing) showed to be particularly effective for the production of zirconia implants with customized surface designs according to the properties required in a specific application. These new surface designs besides to enhance the surface wettability and also to improve the fixation at the initial moment of the implantation, do not significantly compromise the resistance to aging and the mechanical performance of zirconia. Hence, a positive impact on the long-term performance of the zirconia implants may be expected with the proposed novel laser textured surface designs.

The osteoinduction of RGD and Mg ion functionalized bioactive zirconia coating

The objective of this study was to investigate the adhesion, proliferation and mineralization of osteoblasts on arginine-glycine-aspartic acid (RGD)- and magnesium ion (Mg⁺)-decorated zirconia coatings. The zirconia coatings were prepared via a plasma spray; RGD and Mg⁺ were immobilized via a silane-coupling agent and ion implantation, respectively. This study employed scanning electron microscopy (SEM) to observe the surface morphology of RGD- and Mg⁺-decorated zirconia coatings; surface roughness and wettability were also measured. The initial adhesion of osteoblasts was measured, and cell morphology and focal adhesion were observed. In addition, the expressions of the integrins a1, a2, a5, av, and ß1 were measured using RT-PCR. A cell count was conducted to measure proliferation. The expressions of ALP and OCN were detected based on a western blot analysis, and mineralized nodules were observed to visualize the mineralization of osteoblasts. A nanoscale surface structure could be found on the Mg⁺-decorated zirconia coating, and the RGD-decorated zirconia coating showed better wettability (p < 0.05). Cells on the RGD- and Mg⁺-decorated zirconia coating possessed better spreading properties than did cells on nondecorated surfaces, and more focal adhesion was observed. The higher expressions of the integrins a5, av and ß1 were found on the RGD-decorated zirconia coating (p < 0.05). The western blot results demonstrated that the introduction of Mg⁺ heightened the expressions of ALP and OCN. More and bigger mineralized nodules were observed on the Mg⁺- and RGD-decorated zirconia coating, which consisted of small mineralized nodules. RGD- and Mg⁺-functionalized zirconia coating facilitates the osteogenic reaction of osteoblasts. RGD improves the adhesion of osteoblasts, and Mg⁺ benefits the mineralization of osteoblasts. In addition, a synergistic effect was found between RGD and Mg⁺, allowing better performances with regard to adhesion, proliferation and mineralization when the two were used together rather than as separate decorations.

Zirconia surface modifications for implant dentistry

BACKGROUND

Zirconia has emerged as a versatile dental material due to its excellent aesthetic outcomes such as color and opacity, unique mechanical properties that can mimic the appearance of natural teeth and decrease peri-implant inflammatory reactions.

OBJECTIVE

The aim of this review was to critically explore the state of art of zirconia surface treatment to enhance the biological and osseointegration behavior of zirconia in implant dentistry.

MATERIALS AND METHODS

An electronic search in PubMed database was carried out until May 2018 using the following combination of key words and MeSH terms without time periods: "zirconia surface treatment" or "zirconia surface modification" or "zirconia coating" and "osseointegration" or "biological properties" or "bioactivity" or "functionally graded properties".

RESULTS

Previous studies have reported the influence of zirconia-based implant surface on the adhesion, proliferation, and differentiation of osteoblast and fibroblasts at the implant to bone interface during the osseointegration process. A large number of physicochemical methods have been used to change the implant surfaces and therefore to improve the early and late bone-to-implant integration, namely: acid etching, gritblasting, laser treatment, UV light, CVD, and PVD. The development of coatings composed of silica, magnesium, graphene, dopamine, and bioactive molecules has been assessed although the development of a functionally graded material for implants has shown encouraging mechanical and biological behavior.

CONCLUSION

Modified zirconia surfaces clearly demonstrate faster osseointegration than that on untreated surfaces. However, there is no consensus regarding the surface treatment and consequent morphological aspects of the surfaces to enhance osseointegration.

Bioactive poly(etheretherketone) composite containing calcium polyphosphate and multi-walled carbon nanotubes for bone repair: Mechanical property and in vitro biocompatibility

Poly(etheretherketone) exhibits good biocompatibility, excellent mechanical properties, and bone-like stiffness. However, the natural bio-inertness of pure poly(etheretherketone) hinders its applications in biomedical field, especially when direct bone-implant osteo-integration is desired. For developing an alternative biomaterial for load-bearing orthopedic application, combination of bioactive fillers with poly(etheretherketone) matrix is a feasible approach. In this study, a bioactive multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite was prepared through a compounding and injection-molding process for the first time. Bioactive calcium polyphosphate was added to polymer matrix to enhance the bioactivity of the composite, and incorporation of multi-walled carbon nanotubes to composite was aimed to improve both the mechanical property and biocompatibility. Furthermore, the microstructures, surface hydrophilicity, and mechanical property of multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite, as well as the cellular responses of MC3T3-E1 osteoblast cells to this material were investigated. The mechanical testing revealed that mechanical performance of the resulting ternary composite was significantly enhanced by adding the multi-walled carbon nanotubes and the mechanical values obtained were close to or higher than those of human cortical bone. More importantly, cell culture tests showed that initial cell adhesion, cell viability, and osteogenic differentiation of MC3T3-E1 cells were significantly promoted on the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite. Accordingly, the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite may be used as a promising bone repair material in dental and orthopedic applications.

Preparation, mechanical properties and in vitro cytocompatibility of multi-walled carbon nanotubes/poly(etheretherketone) nanocomposites

Desired bone repair material must have excellent biocompatibility and high bioactivity. Moreover, mechanical properties of biomaterial should be equivalent to those of human bones. For developing an alternative biocomposite for load-bearing orthopedic application, combination of bioactive fillers with polymer matrix is a feasible approach. In this study, a series of multi-walled carbon nanotubes (MWCNTs)/poly(etheretherketone) (PEEK) bioactive nanocomposites were prepared by a novel coprecipitation-compounding and injection-molding process. Scanning electron microscope (SEM) images revealed that MWCNTs were adsorbed on the surface of PEEK particles during the coprecipitation-compounding process and dispersed homogeneously in the nanocomposite because the conjugated PEEK polymers stabilized MWCNTs by forming strong π-π stack interactions. The mechanical testing revealed that mechanical performance of PEEK was significantly improved by adding MWCNTs (2-8 wt%) and the experimental values obtained were close to or higher than that of human cortical bone. In addition, incorporation of MWCNTs into PEEK matrix also enhanced the roughness and hydrophilicity of the nanocomposite surface. In vitro cytocompatibility tests demonstrated that the MWCNTs/PEEK nanocomposite was in favor of cell adhesion and proliferation of MC3T3-E1 osteoblast cells, exhibiting excellent cytocompatibility and biocompatibility. Thus, this MWCNTs/PEEK nanocomposite may be used as a promising bone repair material in orthopedic implants application.

Is zirconia a viable alternative to titanium for oral implant? A critical review

PURPOSE

Titanium based implant systems, though considered as the gold standard for rehabilitation of edentulous spaces, have been criticized for many inherent flaws. The onset of hypersensitivity reactions, biocompatibility issues, and an unaesthetic gray hue have raised demands for more aesthetic and tissue compatible material for implant fabrication. Zirconia is emerging as a promising alternative to conventional Titanium based implant systems for oral rehabilitation with superior biological, aesthetics, mechanical and optical properties. This review aims to critically analyze and review the credibility of Zirconia implants as an alternative to Titanium for prosthetic rehabilitation.

STUDY SELECTION

The literature search for articles written in the English language in PubMed and Cochrane Library database from 1990 till December 2016. The following search terms were utilized for data search: "zirconia implants" NOT "abutment", "zirconia implants" AND "titanium implants" AND "osseointegration", "zirconia implants" AND compatibility.

RESULTS

The number of potential relevant articles selected were 47. All the human in vivo clinical, in vitro, animals' studies were included and discussed under the following subheadings: Chemical composition, structure and phases; Physical and mechanical properties; Aesthetic and optical properties; Osseointegration and biocompatibility; Surface modifications; Peri-implant tissue compatibility, inflammation and soft tissue healing, and long-term prognosis.

CONCLUSIONS

Zirconia implants are a promising alternative to titanium with a superior soft-tissue response, biocompatibility, and aesthetics with comparable osseointegration. However, further long-term longitudinal and comparative clinical trials are required to validate zirconia as a viable alternative to the titanium implant.

Effect of Sandblasting Angle and Distance on Biaxial Flexural Strength of Zirconia-based Ceramics

AIM

Surface treatment is necessarily required for bonding of zirconia to the veneering porcelain and luting cements. Sandblasting is the most common and probably the most efficient surface treatment method. Sandblasting roughens the surface and may affect the flexural strength of zirconia. Different sandblasting protocols may yield variable results. This study sought to assess the effect of sandblasting angle and distance on the biaxial flexural strength of zirconia-based ceramics.

MATERIALS AND METHODS

This in vitro experimental study was conducted on 50 zirconia discs measuring 1.2 ± 0.2 mm in thickness and 15 ± 0.2 mm in diameter, which were randomly divided into five groups (n = 10) of one control and four experimental groups subjected to sandblasting with 110 μm aluminum oxide particles under 2 bar pressure for 10 seconds at 15 and 25 mm distances and 45 and 90° angles (between the nozzle head and zirconia surface). Surface roughness was measured by a roughness tester and samples were subjected to thermocycling followed by biaxial flexural strength testing according to ISO6872. The data were analyzed using one-way analysis of variance (p < 0.05).

RESULTS

No statistically significant difference was noted in the mean biaxial flexural strength of the five groups (p = 0.40). Different sandblasting protocols yielded significantly different surface roughness values (p < 0.001). The highest and the lowest mean surface roughness belonged to 15 mm/90° (0.51 μm) and control (0.001 μm) groups respectively.

CONCLUSION

Change in sandblasting angle and distance had no significant effect on the biaxial flexural strength of zirconia-based ceramic, but surface roughness was significantly different in the study groups. Clinical significances: Regardless of sandblasting angle, increasing distance to 25 mm significantly decreases surface roughness that may negatively affect zirconia bond strength.

Enhancing the Bioactivity of Yttria-Stabilized Tetragonal Zirconia Ceramics via Grain-Boundary Activation

Yttria-stabilized tetragonal zirconia (Y-TZP) has been proposed as a potential dental implant because of its good biocompatibility, excellent mechanical properties, and distinctive aesthetic effect. However, Y-TZP cannot form chemical bonds with bone tissue because of its biological inertness, which affects the reliability and long-term efficacy of Y-TZP implants. In this study, to improve the bioactivity of Y-TZP ceramics while maintaining their good mechanical performance, Y-TZP was modified by grain-boundary activation via the infiltration of a bioactive glass (BG) sol into the surface layers of Y-TZP ceramics under different negative pressures (atmospheric pressure, -0.05 kPa, and -0.1 kPa), followed by gelling and sintering. The in vitro bioactivity, mechanical properties, and cell behavior of the Y-TZP with improved bioactivity were systematically investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), electron probe microanalysis (EPMA), and Raman spectroscopy. The results of the bioactivity test conducted by immersing Y-TZP in simulated body fluid (SBF) showed that a bonelike apatite layer was produced on the entire surface. The mechanical properties of the modified Y-TZP decreased as the negative pressure in the BG-infiltration process increased relative to those of the Y-TZP blank group. However, the samples infiltrated with the BG sol under -0.05 kPa and atmospheric pressure still retained good mechanical performance. The cell-culture results revealed that the bioactive surface modification of Y-TZP could promote cell adhesion and differentiation. The present work demonstrates that the bioactivity of Y-TZP can be enhanced by grain-boundary activation, and the bioactive Y-TZP is expected to be a potential candidate for use as a dental implant material.

In vitro biological outcome of laser application for modification or processing of titanium dental implants

There are numerous functions for laser in modern implant dentistry including surface treatment, surface coating, and implant manufacturing. As laser application may potentially improve osseointegration of dental implants, we systematically reviewed the literature for in vitro biological responses to laser-modified or processed titanium dental implants. The literature was searched in PubMed, ISI Web, and Scopus, using keywords "titanium dental implants," "laser," "biocompatibility," and their synonyms. After screening the 136 references obtained, 28 articles met the inclusion criteria. We found that Nd:YAG laser was the most commonly used lasers in the treatment or processing of titanium dental implants. Most of the experiments used cell attachment and cell proliferation to investigate bioresponses of the implants. The most commonly used cells in these assays were osteoblast-like cells. Only one study was conducted in stem cells. These in vitro studies reported higher biocompatibility in laser-modified titanium implants. It seems that laser radiation plays a vital role in cell response to dental implants; however, it is necessary to accomplish more studies using different laser types and parameters on various cells to offer a more conclusive result.

The evaluation of prepared microgroove pattern by femtosecond laser on alumina-zirconia nano-composite for endosseous dental implant application

Ceramic dental materials, especially alumina (20 %vol)-yttrium stabilized tetragonal zirconia poly crystal (A-Y-TZP20), have been considered as alternatives to metals for endosseous dental implant application. For increasing the bone-to-implant contact as well as the speed of bone formation, a new surface modification can be effective. The aim of this study was to design microgroove patterns by femtosecond laser on A-Y-TZP20 nano-composite disks for endosseous dental implant application. The phase composition and the morphology of the A-Y-TZP20 nano-composite samples were characterized using X-ray diffraction and Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy techniques. Statistical analysis was submitted to Kolmogorov-Smirnov test and Student's t test for independent variables, with a 5 % significance level. EDAX analysis revealed a significant decrease in the relative content of contaminants like carbon (p < 0.05) in laser surface-treated group as compared to non surface-treated group. X-ray diffraction did not show any change in the crystalline structure induced by laser processing. It was concluded that the femtosecond laser is a clean and safe method for surface modification of A-Y-TZP20.

Surface free energy predominates in cell adhesion to hydroxyapatite through wettability

The initial adhesion of cells to biomaterials is critical in the regulation of subsequent cell behaviors. The purpose of this study was to investigate a mechanism through which the surface wettability of biomaterials can be improved and determine the effects of biomaterial surface characteristics on cellular behaviors. We investigated the surface characteristics of various types of hydroxyapatite after sintering in different atmospheres and examined the effects of various surface characteristics on cell adhesion to study cell-biomaterial interactions. Sintering atmosphere affects the polarization capacity of hydroxyapatite by changing hydroxide ion content and grain size. Compared with hydroxyapatite sintered in air, hydroxyapatite sintered in saturated water vapor had a higher polarization capacity that increased surface free energy and improved wettability, which in turn accelerated cell adhesion. We determined the optimal conditions of hydroxyapatite polarization for the improvement of surface wettability and acceleration of cell adhesion.

A Critical Review of Dental Implant Materials with an Emphasis on Titanium versus Zirconia

The goal of the current publication is to provide a comprehensive literature review on the topic of dental implant materials. The following paper focuses on conventional titanium implants and more recently introduced and increasingly popular zirconia implants. Major subtopics include the material science and the clinical considerations involving both implant materials and the influence of their physical properties on the treatment outcome. Titanium remains the gold standard for the fabrication of oral implants, even though sensitivity does occur, though its clinical relevance is not yet clear. Zirconia implants may prove to be promising in the future; however, further in vitro and well-designed in vivo clinical studies are needed before such a recommendation can be made. Special considerations and technical experience are needed when dealing with zirconia implants to minimize the incidence of mechanical failure.

Enhanced osteoblast cells adhesion, spreading, and proliferation to surface-carboxylated poly(etheretherketone)

Poly(etheretherketone) is a rigid semicrystalline thermoplastic that combines excellent mechanical properties, broad chemical resistance, and bone-like stiffness, and is widely used in biomedical fields. However, the hydrophobic bio-inert surface of poly(etheretherketone) tends to hinder its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this investigation, poly(etheretherketone) surface was functionalized by a method with chemistry analogous to the formation of organosilane self-assembled monolayers on glass or silicon. First, poly(etheretherketone) surface activation with selective carbonyl reduction introduces surface hydroxylation. And then treatment of the hydroxylation-pretreated poly(etheretherketone) samples with a substituted organosilane solution forms the carboxyl (–COOH) functional surface layers. The modified surfaces were characterized using X-ray photoelectron spectroscopy, water contact angle measurements, differential scanning calorimetry, X-ray diffraction, and surface profiler. The effect of cell adhesion, spreading, and proliferation on each specimen was investigated. Pre-osteoblast cells (MC3T3-E1) adhesion, spreading, and proliferation were improved remarkably on surface-carboxylated poly(etheretherketone). Poly(etheretherketone) modified with –COOH on its surface has potential use in orthopedic or dental implants.

Cytocompatibility and early osseointegration of nanoTiO2-modified Ti-24 Nb-4 Zr-7.9 Sn surfaces

This study aimed to evaluate the cytocompatibility and early osseointegration of Ti-24 Nb-4 Zr-7.9 Sn (Ti-2448) surfaces that were modified with a nanoscale TiO2 coating. The coating was fabricated using a hydrothermal synthesis method to generate nanoTiO2/Ti-2448. The surface characteristics of the samples were evaluated using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The cytotoxicity of the fabricated nanoTiO2/Ti-2448 was determined using MTT assays. The proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts cultured on nanoTiO2/Ti-2448 were compared with those cultured on Ti-2448. Disk-shaped implants were placed in Wistar rats. The histological sections were stained with haematoxylin and eosin (HE), and the histocompatibility was analysed at 4 and 12weeks post-implantation. Cylindrical implants were embedded in Japanese white rabbits, and the histological sections were stained with HE and anti-TGF-β1 to evaluate the histocompatibility and early osseointegration at 4, 12 and 26weeks post-implantation. NanoTiO2/Ti-2448 exhibited a rougher surface than did Ti-2448. NanoTiO2/Ti-2448 was determined to be non-cytotoxic. More osteoblasts and higher ALP activity were observed for nanoTiO2/Ti-2448 than Ti-2448 (p<0.05). Few inflammatory cells were detected around nanoTiO2/Ti-2448, and the expression of TGF-β1 on nanoTiO2/Ti-2448 peaked at earlier time than that on Ti-2448. The results indicate that the cytocompatibility and early osseointegration were enhanced by the nanoTiO2 coating.

Influence of plasma and ultraviolet treatment of zirconia on initial attachment of human oral keratinocytes: expressions of laminin γ2 and integrin β4

Initial attachment of human oral keratinocytes cultured on yttria-stabilized tetragonal zirconia polycrystal (TZP) surfaces that were subjected to UV or oxygen plasma (O2-plasma) treatment was investigated. The viability of the attached cells, mRNA expression of laminin γ2 and integrin β4, distribution of laminin γ2 and integrin β4, cell area, and cell morphology were assessed. The results showed that no differences in the viability of attached cells were recognized among the conditions. However, expression of laminin γ2 and integrin β4 as well as cell morphology were promoted only in O2-plasma specimens even though superhydrophilicity was obtained in both the UV and O2-plasma specimens compared with the untreated control specimen. The photocatalytic activity was believed to be closely involved in the above-mentioned differences. The results of this study suggest that TZP surface treated with oxygen plasma promotes the initial attachment capability of human oral keratinocytes with enhancing the extracellular matrix such as laminin γ2.

Functionalized ceramics for biomedical, biotechnological and environmental applications

Surface functionalization has become of paramount importance and is considered a fundamental tool for the development and design of countless devices and engineered systems for key technological areas in biomedical, biotechnological and environmental applications. In this review, surface functionalization strategies for alumina, zirconia, titania, silica, iron oxide and calcium phosphate are presented and discussed. These materials have become particularly important concerning the aforementioned applications, being not only of great academic, but also of steadily increasing human and commercial, interest. In this review, special emphasis is given to their use as biomaterials, biosensors, biological targets, drug delivery systems, implants, chromatographic supports for biomolecule purification and analysis, and adsorbents for toxic substances and pollutants. The objective of this review is to provide a broad picture of the enormous possibilities offered by surface functionalization and to identify particular challenges regarding surface analysis and characterization.

Creation of nanoporous TiO2 surface onto polyetheretherketone for effective immobilization and delivery of bone morphogenetic protein

This study evaluated the utility of the creation of a nanoporous TiO2 surface to enhance the in vitro biocompatibility and in vivo osseoconductivity of polyetheretherketone (PEEK) implants by providing favorable sites for the effective immobilization of bone morphogenetic protein-2 (BMP-2). A uniform nanoporous TiO2 layer with a pore diameter of ∼70 nm was successfully created by anodizing a Ti film, which had been deposited onto a PEEK substrate via electron beam (e-beam) evaporation technique. This nanoporous, hydrophilic TiO2 surface enabled the efficient immobilization of BMP-2, resulting in a remarkable enhancement in in vitro biocompatibility that was assessed in terms of cell attachment, proliferation, and differentiation. The in vivo animal tests also confirmed that the nanoporous TiO2 surface immobilized with BMP-2 could significantly enhance the osseoconductivity of PEEK implants. The BMP-immobilized PEEK implant with the nanoporous TiO2 surface showed much higher bone-to-implant contact (BIC) ratio (60%) than the bare PEEK (30%), PEEK with the nanoporous TiO2 surface (50%) and even BMP-immobilized PEEK without the nanoporous TiO2 surface (32%).

Characterization of wet powder-sprayed zirconia/calcium phosphate coating for dental implants

PURPOSE

Yttria-stabilized zirconia (TZ) is used for dental applications because of its low toxicity and beneficial mechanical properties, but it does not stimulate bone regeneration around the implant due to its bioinertness. Therefore, hydroxyapatite (HA) coatings are often utilized to increase the surface bioactivity and to achieve a better osseointegration. These coatings, however, are chemically nonstable and provide a weak bonding to the substrate surface.

MATERIALS AND METHODS

In this study, zirconia substrates were coated with a calcium phosphate/zirconia mixture to achieve ceramic coatings with a high bioactivity potential and a good mechanical stability. The coatings were obtained by wet powder spraying (WPS). Pure HA and TZ coatings were employed as reference materials. The coatings were characterized with regard to microstructure, surface roughness, and phase composition. Scratch tests were carried out to investigate the coating adhesion. The influence of the coating on the mechanical strength was evaluated with the ball on three balls test (B3B). In addition, zirconia dental implant screws were also coated and inserted in a biomechanical test block and bovine rip bone.

RESULTS

After sintering, the mixed coating exhibited a porous morphology with a surface roughness of about 4 μm and a total porosity of 17%. Phase analysis showed a transformation from TZ and HA to calcium zirconium oxide and tricalcium phosphate. Investigations of the bond strength confirmed a strong adhesion of the mixed coating to the substrate, while the biaxial fracture strength was only slightly affected. Insertion experiments confirmed the scratch test results and evidenced an intact mixed coating on the zirconia screw.

CONCLUSIONS

The present study revealed a higher stability and firm adhesion of the mixed coating compared with a pure calcium phosphate coating. We also successfully demonstrate the particular versatility of the WPS technique for dental implants by coating a complex curved surface.

Hybrid micro/nano-topography of a TiO2 nanotube-coated commercial zirconia femoral knee implant promotes bone cell adhesion in vitro

Various approaches have been studied to engineer the implant surface to enhance bone in-growth properties, particularly using micro- and nano-topography. In this study, the behavior of osteoblast (bone) cells was analyzed in response to a titanium oxide (TiO2) nanotube-coated commercial zirconia femoral knee implant consisting of a combined surface structure of a micro-roughened surface with the nanotube coating. The osteoblast cells demonstrated high degrees of adhesion and integration into the surface of the nanotube-coated implant material, indicating preferential cell behavior on this surface when compared to the bare implant. The results of this brief study provide sufficient evidence to encourage future studies. The development of such hierarchical micro- and nano-topographical features, as demonstrated in this work, can provide insightful designs for advanced bone-inducing material coatings on ceramic orthopedic implant surfaces.

Enhanced osteoblastic cell response on zirconia by bio-inspired surface modification

Excellent esthetic properties and limited plaque adhesion make zirconia ceramics an ideal material for implants in the fields of dentistry and orthopedics. Unfortunately, the physicochemical stability of zirconia makes it difficult to improve biocompatibility through surface modification. The dopamine-derived residue, 3,4-dihydroxy-L-phenylalanine (L-DOPA), has been identified as an important molecule secreted by marine mussels for the formation of adhesive pads. This study coated zirconia with L-DOPA to improve the biocompatibility of ZrO2. As confirmed by contact angle and X-ray photoelectron spectroscopy (XPS), the formation of L-DOPA film can be controlled by varying the process temperature. Results from scanning electron microscopy (SEM) and atomic force microscopy (AFM) show that the topography of the zirconia substrate was preserved after being coated with a film of L-DOPA. Specifically, the thickness of the coating and initial cell spreading ability were both enhanced by preparing samples at higher temperatures. L-DOPA coated zirconia demonstrated better cyto-compatibility than uncoated specimens, as indicated by cell responses such as cell spreading and proliferation. These preliminary results suggest that L-DOPA film could be used to improve the cyto-compatibility of zirconia and further has the potential to immobilize other biofunctional molecules in biomedical applications.

A comparison of biocompatibility and osseointegration of ceramic and titanium implants: an in vivo and in vitro study

This study compared the biocompatibility in vitro and the osseointegration in vivo of zirconium and titanium implants regarding implant surfaces and the bone-implant contacts. The different implant surfaces and the biocompatibility of zirconium versus titanium implants were determined by vitality and cytotoxic tests in vitro. The contact of the osteoblasts to the implant surface was determined by scanning electron microscopy (SEM). The in vivo study for osseointegration was performed in domestic pigs over 4 and 12 weeks. In each animal, 4 zirconium and 4 titanium implants (WhiteSky, BlueSky, Bredent, Germany) were inserted in the os frontale and analysed by histomorphometry. Cytotoxicity and SEM showed good biocompatibility in relation to the investigated implant materials. Histological results showed direct bone-implant contact of the implant surfaces. The zirconium implants showed a slight delay in osseointegration in terms of bone-implant contact as measured by histomorphometry (after 4 weeks, zirconium (59.3 ± 4.6%) versus titanium (64.1 ± 3.9%); after 12 weeks, zirconium (67.1 ± 2.3%) versus titanium (73.6 ± 3.2%). A statistically significant difference between the two groups was not observed. The results indicated similar biocompatibility and osseointegration for zirconium compared to titanium implants.

Immediate provisional restoration of single-piece zirconia implants: a prospective case series - results after 24 months of clinical function

OBJECTIVE

Aim of this prospective case series was to evaluate the outcome of immediately provisionalized single-piece zirconia implants.

MATERIAL AND METHODS

A total of 20 zirconia implants were inserted in single-tooth gaps in the maxilla (11) and mandible (9) of 20 patients. Implants were restored with all-ceramic CAD/CAM provisionals without occlusal contacts immediately after placement. Permanent all-ceramic restoration was performed 4 months after surgery. Plaque index (PI), bleeding on probing (BOP), Periotest(®) (PV), pink aesthetic score (PES), mean radiographic marginal bone levels (MBL), implant survival and success were evaluated up to 24 months.

RESULTS

Assessment of PI at baseline and follow-ups after 6, 12, 18 and 24 months revealed 27% (±5.3), 24% (±6), 23% (±6.1), 23% (±5.3) and 22% (±6.4), respectively. Evaluation of BOP revealed 25% (±5.6), 21% (±6), 21% (±7.2), 18% (±5.9) and 15% (±5.5), respectively. Implants presented stable at follow-ups (PV). PES improved, but not statistically significant from 8.13 (±1.5) at baseline to 10 (±2) 24 months after implantation. Measurements of MBL showed a significant bone loss of 1.01 mm within the first year after placement (P < 0.001) and 1.29 mm 24 months post-implant insertion, not reaching further statistically significant levels (P > 0.05). One implant was lost 4 months after placement, resulting in a survival and success rate of 95%.

CONCLUSION

Clinical and radiographic parameters demonstrated a 95% integration of immediately loaded zirconia single-piece implants. A long-term randomized-controlled clinical trial was initiated to confirm evidence of this protocol.

Surface damages of zirconia by Nd:YAG dental laser irradiation

The purpose of this study was to characterize the surface damages of zirconia by Nd:YAG dental laser irradiation through a systematic evaluation of the associated microstructural changes. Disk specimens of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) and ceria-stabilized zirconia/alumina nanocomposite (Ce-TZP/Al₂O₃ nanocomposite) were irradiated by Nd:YAG dental laser. The specimens were characterized using scanning electron microscopy, X-ray diffractometry, and wavelength dispersive X-ray spectroscopy. Every single irradiated spot was indicated by a circular black pit surrounded by a circular raised rim with a sunken depression at the center. On surface changes, many cracks were formed inside each irradiated pit. On changes in elemental composition, the concentration of oxygen decreased while that of zirconium increased. After heating in air, the assembly of circular black pits turned white, although the depression and raised rim remained. This study showed that Nd:YAG dental laser irradiation induced cracking and reduced oxygen content on the surface of zirconia. Consequently, these phenomena reduced the mechanical strength of zirconia. Therefore, Nd:YAG dental laser welding should not be performed on tetragonal zirconia.

Comparison of zirconia and titanium implants after a short healing period. A pilot study in minipigs

The aim of this animal study was to investigate and compare the osseointegration of zirconia and titanium dental implants. 14 one-piece zirconia implants and 7 titanium implants were inserted into the mandibles of 7 minipigs. The zirconia implants were alternately placed submerged and non-submerged. To enable submerged healing, the supraosseous part was removed, using a diamond saw. The titanium implants were all placed submerged. After a healing period of 4 weeks, a histological analysis of the soft and hard tissue and a histomorphometric analysis of the bone-implant contact (BIC) and relative peri-implant bone-volume density (rBVD; relation to bone-volume density of the host bone) was performed. Two zirconia implants were found to be loose. All other implants were available for evaluation. For submerged zirconia and titanium implants, the implant surface showed an intimate connection to the neighbouring bone, with both types achieving a BIC of 53%. For the non-submerged zirconia implants, some crestal epithelial downgrowth could be detected, with a resultant BIC of 48%. Highest rBVD values were found for submerged zirconia (80%), followed by titanium (74%) and non-submerged zirconia (63%). The results suggest that unloaded zirconia and titanium implants osseointegrate comparably, within the healing period studied.

Laser-assisted Zr/ZrO(2) coating on Ti for load-bearing implants

Oxidized Zr alloys have been shown to exhibit lower friction and superior wear properties, suggesting that they could be used in hip and knee implants. However, conventional oxidation of Zr alloys above 500 degrees C, in dry air, for several hours has been shown to have detrimental effects on the substrate's properties. In this work, we deposited pure Zr on Ti, then oxidized the coating using a continuous-wave Nd:YAG laser, which facilitated localized heating to elevated temperatures without affecting the substrate. Laser-assisted oxidation resulted in a 7microm thick fully dense ZrO(2) layer on Zr in which an increase in oxidation kinetics was evident due to an increase in the laser power and/or the oxygen partial pressure. Due to its high surface energy and wettability, the wear rate of laser-oxidized Zr was two orders of magnitude less compared to that of as-deposited Zr. The oxidized coatings showed comparable in vitro biocompatibility to that of pure Ti and excellent in vitro cell-material interactions. This article reports the processing of Zr/ZrO(2) coatings on Ti using lasers, and the influence of laser parameters and oxygen partial pressure on the coating's mechanical, microstructural, wear and in vitro biological properties using human osteoblast cells.