Yttria-tetragonal Zirconia Polycrystal Research Articles

Biomolecular modification of zirconia surfaces for enhanced biocompatibility

Yttria-tetragonal zirconia polycrystal (Y-TZP) is a preferred biomaterial due to its good mechanical properties. In order to improve the biocompatibility of zirconia, RGD-peptide derived from extracellular matrix proteins was employed to modify the surface of Y-TZP to promote cell adhesion in this study.The surface of Y-TZP specimens was first modified using a hydrothermal method for different lengths of time. The topographies of modified Y-TZP specimens were analyzed by contact angle, XRD, FTIR, AFM, and FE-SEM. The mechanical properties were evaluated using Vickers hardness and three point bending strength. Then, the RGD-peptide was immobilized on the surface of the Y-TZP by chemical treatment. These RGD-peptide immobilized Y-TZP specimens were characterized by FTIR and AFM, and then were cocultured with MG-63 osteoblast cells for biocompatibility assay. The cell morphology and proliferation were evaluated by SEM, WST-1, and ALP activity assay.The XRD results indicated that the phase transition, from tetragonal phase to monoclinic phase, was increased with a longer incubation time of hydrothermal treatment. However, there were no significant differences in mechanical strengths after RGD-peptide was successfully grafted onto the Y-TZP surface. The SEM images showed that the MG-63 cells appeared polygonal, spindle-shaped, and attached on the RGD-peptide immobilized Y-TZP. The proliferation and cellular activities of MG-63 cells on the RGD-peptide immobilized Y-TZP were better than that on the unmodified Y-TZP.From the above results, the RGD-peptide can be successfully grafted onto the hydrothermal modified Y-TZP surface. The RGD-peptide immobilized Y-TZP can increase cell adhesion, and thus, improve the biocompatibility of Y-TZP.

The effect of sandblasting and different primers on shear bond strength between yttria-tetragonal zirconia polycrystal ceramic and a self-adhesive resin cement.

To evaluate the effect of zirconia primers, air-abrasion, and tribochemical surface treatment methods on the shear bond strength between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic and self-adhesive resin cement. Y-TZP ceramic surfaces were ground flat with 600-grit silicon carbide paper and then divided into seven groups of 10 and treated as follows: untreated (control), Monobond Plus, Z-PRIME Plus, ESPE Sil with CoJet, air-abrasion, Monobond Plus with air-abrasion, and Z-PRIME Plus with air-abrasion. Self-adhesive resin cement was placed onto the treated Y-TZP specimens for each group. All specimens were thermocycled and subjected to a shear bond strength test. Scanning electron microscope images of the fractured areas and x-ray diffraction (XRD) analysis of the surface-treated Y-TZP specimens were performed. Data were statistically analyzed using one-way analysis of variance and the Student-Newman-Keuls multiple comparison test (p<0.05). The Z-PRIME Plus treatment in combination with air-abrasion produced the highest bond strength (16.50±2.26 MPa), followed by air-abrasion (10.56±3.32 MPa), and then Monobond Plus combined with air-abrasion (8.93±3.13 MPa), ESPE Sil after CoJet application (8.54±3.98 MPa), and the Z-PRIME Plus group (8.27±2.79 MPa). The control (3.91±0.72 MPa) and Monobond Plus (4.86±1.77 MPa) groups indicated the lowest results (p<0.05). The XRD results showed the peaks of the monoclinic phase for the air-abrasion and CoJet treatment groups compared with the Y-TZP control. Z-PRIME Plus primer application after air-abrasion presented the best results for improving the bond strength between Y-TZP ceramic and self-adhesive resin cement.

Grain-boundary cation diffusion in ceria tetragonal zirconia determined by constant-strain-rate deformation tests

Ceria tetragonal zirconia polycrystals with a content of 12 mol% ceria (CeTZP) have been tested in compression at constant strain rate between 1150 °C and 1300 °C. An accurate analysis of the stress–strain curves has permitted to determine the value of the grain boundary cation diffusion. The results are compared with those reported in literature for this alloy and yttria tetragonal zirconia polycrystals (YTZP). An isotopic effect is found to correlate both grain boundary diffusion coefficients.

Zirconia dental implants: a clinical, radiographic, and microbiologic evaluation up to 3 years.

To retrospectively evaluate the clinical performance of zirconia endosseous implants. Partially edentulous patients with adequate bone volume to fit yttria tetragonal zirconia polycrystal (Y-TZP) implants at least 3.5 mm wide and 8.0 mm long were included. Full-mouth probing pocket depth (PPDs) and percentage bleeding on probing (BOP) scores around teeth and implant(s) were assessed and compared. Marginal bone loss/gain relative to baseline was measured on intraoral radiographs, and the prevalence and quantities of seven periodontal bacteria were assessed around implants and teeth in the same patient. Seventy-four consecutively treated patients with 121 zirconia implants (66 two-piece implants and 55 one-piece implants) were clinically evaluated after a mean observation period of 18 months. Three implants had failed and had been removed, for a cumulative implant survival rate of 96.5% (± 2.0%) after 3 years. The 118 surviving implants demonstrated healthy mucosal conditions, with low mean PPDs (1.8 ± 0.4 mm) and mean BOP scores (4.1% ± 4.2%). PPD and BOP were statistically significantly lower around implants than around teeth. BOP and PPD around implants and teeth were significantly correlated. Stable marginal bone levels were observed (mean bone loss of 0.1 ± 0.6 mm after 3 years). The frequency of isolation of all marker bacteria was similar at tooth and implant sites. Zirconia endosseous implants can achieve a 3-year implant survival rate in partially edentulous patients, similar to that of titanium implants, with healthy and stable soft and hard tissues.

The use of MDP-based materials for bonding to zirconia

A strong and stable bond between the luting resin and overlying ceramic restoration is critical to longevity, but no technique has been established for how to provide such a bond when the core material is zirconia. The purpose of this study was to evaluate the effect of different materials containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) on the bond strength to yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic. Forty Y-TZP slices (Lava) were cemented to substrates (8 groups; n=5 in each) with or without the previous application of an experimental primer (0.5% MDP) or an MDP-based adhesive (Clearfil S3 Bond Plus or Scotchbond Universal) with either an MDP (Clearfil SA) or a non-MDP (RelyX Ultimate) luting resin. Specimens were cut, stored in distilled water, and microtensile tested (5 beams per specimen) at 48 hours and again at 6 months after luting procedures. The data were analyzed by 4-way ANOVA (α=.05) and the Tukey test (α=.05). The mode of failure was classified with a stereomicroscope, and the treated surfaces were analyzed with energy-dispersive x-ray spectroscopy. Both adhesive (P<.001) and time (P<.001) significantly affected bond strength. The interaction of any of the factors was not significant. The use of an MDP-containing adhesive and the shorter storage time were associated with higher bond strengths. At 48 hours, an overall incidence of 50.5% of Type 1 mode of failure (adhesive at ceramic/resin interface) occurred, as opposed to 68% after 6 months of water storage. Energy-dispersive x-ray spectroscopy results showed peaks of carbon and phosphorus when MDP-based materials were used. The application of an MDP-based adhesive may improve bond strength to zirconia. However, microtensile bond strength results for all groups did not remain stable over 6 months.

Evaluation of the shear bond strength of resin cement to Y‐TZP ceramic after different surface treatments

The purpose of this study was to evaluate the effect of various surface treatments on the shear bond strength of Y-TZP (Yttria-Tetragonal Zirconia Polycrystal) ceramics with zirconia primer and two different resin cements both containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Zirconia blocks (LAVA, 3M ESPE, St. Paul, MN) were polished and assigned to five groups according to the surface treatment: (1) no further treatment (control); (2) airborne abrasion with Al2 O3 particles; (3) Z-PRIME Plus (Bisco, Schaumburg, IL) applied on polished zirconia; (4) Z-PRIME Plus applied on zirconia after airborne abrasion; and (5) tribochemical silica-coating performed with the CoJet system (3M ESPE) followed by application of ESPE®-Sil (3M ESPE). Each group was further divided into one of two resin cements: Panavia F2.0 (Kuraray, Kurashiki, Okayama, Japan) and Clearfil SA Luting (Kuraray). Resin cement placed inside a gel-cap was polymerized on the zirconia surface. Shear bond strength was tested with a universal testing machine at 0.5 mm/min. One-way analysis of variance and paired t-test were done. (p < 0.05), and scanning electron microscope (SEM) images were taken. Zirconia primer applied after airborne abrasion significantly increased the shear bond strength resulting in the highest value for both resin cements. Control groups for both cements showed the weakest value for shear bond strength. No significant differences were found between the shear bond strengths of the individual resin cements applied to zirconia surfaces treated the same way. In conclusion, the combined surface treatment of airborne abrasion followed by a zirconia primer is recommended for zirconia bonding with Panavia F2.0 and Clearfil SA Luting cements.

Residual stress profiles in veneering ceramic on Y-TZP, alumina and ZTA frameworks: Measurement by hole-drilling

ObjectivesThe residual stress profile developed within the veneering ceramic during the manufacturing process is an important predicting factor in chipping failures, which constitute a well-known problem with yttria-tetragonal-zirconia polycrystal (Y-TZP) based restorations. The objectives of this study are to measure and to compare the residual stress profile in the veneering ceramic layered on three different polycrystalline ceramic framework materials: Y-TZP, alumina polycrystal (AL) and zirconia toughened alumina (ZTA). MethodsThe stress profile was measured with the hole-drilling method in bilayered disk samples of 19mm diameter with a 0.7mm thick Y-TZP, AL or ZTA framework and a 1.5mm thick layer of the corresponding veneering ceramic. ResultsThe AL samples exhibited increasing compressive stresses with depth, while compressive stresses switching into interior tensile stresses were measured in Y-TZP samples. ZTA samples exhibited compressive stress at the ceramic surface, decreasing with depth up to 0.6mm from the surface, and then becoming compressive again near the framework. SignificanceY-TZP samples exhibited a less favorable stress profile than those of AL and ZTA samples. Results support the hypothesis of the occurrence of structural changes within the Y-TZP surface in contact with the veneering ceramic to explain the presence of tensile stresses. Even if the presence of Y-TZP in the alumina matrix seems to negatively affect the residual stress profiles in ZTA samples in comparison with AL samples, the registered profiles remain positive in terms of veneer fracture resistance.

Influence of roughness on the efficacy of grazing incidence X-ray diffraction to characterize grinding-induced phase changes in yttria-tetragonal zirconia polycrystals (Y-TZP)

Zirconia-based dental prostheses undergo various grinding steps and heat treatments in preparation for dental patient use. Post-sintered grinding induces a tetragonal-to-monoclinic phase transformation that may lead to failure. These grinding conditions were simulated on fully sintered yttria-stabilized zirconia (Ivoclar IPS e.max ZirCAD, Ivoclar Vivadent, Schaan, Liechtenstein) using two applied loads (10 and 40 N) and different sizes of diamond grinding media (15-, 45-, and 70-μm particles). X-ray diffraction (XRD) and Raman spectroscopy were shown to be inadequate to analyze the monoclinic phase within the surface. Grazing incidence XRD correctly identified the presence of monoclinic phase on the ground zirconia surfaces. However, we conclude that, given the resulting ground microstructure, this technique only provides a qualitative measure for the depth profiles of the monoclinic phase for different grinding conditions. It was shown that regeneration of zirconia converts all monoclinic phase to the tetragonal phase, including conversion in specimens that were subjected to the harshest grinding conditions.

Development of electrically conductive zirconia Part1: The optimal process parameters and mechanical properties

Abstract The Taguchi method was applied to analyze the optimum process parameters of a 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) containing 30 wt% titanium nitride (TiN) (3Y-TZP/TiN). Four process parameters—(1) sintering type, (2) crushing time of TiN powder, (3) the first-step sintering duration, and (4) the second-step sintering temperature were chosen as the controlling factors. Fracture toughness, flexural strength, hardness, relative density, and electric resistance were examined using an L 9 orthogonal array. The results indicated that the fracture toughness was mainly affected by the duration of the first sintering step. The highest fracture toughness (9.275 MPa m 1/2 ) was achieved at 97.3 vol% of the tetragonal phase in 3Y-TZP/TiN. In addition, 3Y-TZP/TiN possessing a high fracture toughness of 8.59 MPa m 1/2 and a flexural strength of 680.77 MPa was fabricated using the optimum process parameters, 8 h crushing time of TiN powder, and the two-step sintering process. The electric resistance for 3Y-TZP/TiN was 3.26×10 −3 Ω cm.

Fibrin Clot Extension on Zirconia Surface for Dental Implants: A Quantitative In Vitro Study

The surface chemical and physical properties of materials used for implants have a major influence on blood clot organization. This study aims to evaluate the blood clot extension (bce) on zirconia and titanium. bce was measured in association to surface roughness (Ra) and static contact angle (θ). Forty disk-shaped samples of sandblasted yttria tetragonal zirconia polycrystal (sb-YTZP), machined titanium (m-Ti), and sandblasted, high-temperature, acid-etched titanium (p-Ti) were used in the present study. About 0.2 mL of human blood, immediately dropped onto the specimen's surface and left in contact for 5 minutes at room temperature, was used to measure the bce. Specimens were observed under confocal scanning laser and scanning electron microscopes. The bce (mean × 10(7) ± standard deviation [SD] × 10(6) μm(2) ) was 2.97 ± 6.68 for m-Ti, 5.64 ± 6.83 for p-Ti, and 3.61 ± 7.67 for sb-YTZP. p-Ti samples showed a significantly higher bce. Ra (mean ± SD [μm]) was 0.56 ± 0.7 for m-Ti, 3.78 ± 0.8 for p-Ti, and 2.68 ± 0.6 for sb-YTZP. The difference was not significant between sb-YTZP and p-Ti. θ (mean ± SD) was 55.6 ± 5.6 for m-Ti, 48.7 ± 2.8 for sb-YTZP, and 38.0 ± 2.2 for p-Ti. The difference was not significant between m-Ti and sb-YTZP. The sb-YTZP demonstrated a significantly lesser amount of bce compared with p-Ti specimens, notwithstanding that any significant difference was present between Ra and θ.

Dense and Cellular Zirconia Produced by Gel Casting with Agar: Preparation and High Temperature Characterization

A modified gel-casting process was developed to produce both dense and highly porous (40% volume) yttria tetragonal zirconia polycrystal (Y-TZP) using agar, a natural polysaccharide, as gelling agent. A fugitive phase, made of commercial polyethylene spheres, was added to the ceramic suspension before gelling to produce cellular ceramic structures. The characterization of the microstructural features of both dense and cellular ceramics was carried out by FEG SEM analysis of cross-sections produced by focused ion beam. The mechanical properties of the components were characterized at room temperature by nanoindentation tests in continuous stiffness measurement mode, by investigating the direct effect of the presence of residual microporosity. The presence of a diffuse residual microporosity from incomplete gel deaeration resulted in a decay of the bending strength and of the elastic modulus. The mechanical behavior of both dense and cellular zirconia (in terms of elastic modulus, flexural strength, and deformation at rupture) was investigated by performing four-point bending tests at the temperature of 1500°C.

Microstructural changes produced by abrading Y-TZP in presintered and sintered conditions

ObjectiveTo evaluate the effect of abrading before and after sintering using alumina-based abrasives on the surface of yttria-tetragonal zirconia polycrystals. Particular attention was paid to the amount of surface stress-assisted phase transformation (tetragonal→monoclinic) and the presence of microcracks. MethodsPre-sintered zirconia ceramic specimens (ZirCAD; Ivoclar Vivadent) were first surface-ground flat with #600–800–1000-grit SiC paper. They were then surface-treated with different grain size abrasives before and after the sintering step. Samples that underwent no surface treatment were used as controls. For each condition, eight specimens were prepared. The physical/mechanical characteristics of zirconia material were determined by measuring density, porosity, grain size, hardness, and fracture toughness. The effects of surface treatments were assessed by surface roughness measurements, quantitative X-ray diffraction analysis, and scanning electron microscopy. ResultsWith increased dimensions of the abrasive particles, the abraded surfaces of zirconia specimens exhibited a widespread system of microcracks and an increased monoclinic zirconia quantity. These structural changes likely affect the aging of the material during its clinical service.

Brasagem da zircônia metalizada com titânio à liga Ti-6Al-4V

Zircônia tetragonal estabilizada com ítria foi mecanicamente metalizada com titânio e a condição de molhamento avaliada com as ligas convencionais Ag-28Cu e Au-18Ni. Estas dissolveram o revestimento de titânio para uma completa distribuição deste metal ativo na superfície cerâmica, gerando uma liga ativa in situ e possibilitando adequadas ligações químicas ao metal base na temperatura de união. Os melhores resultados de molhamento foram selecionados para brasagem indireta em forno de alto-vácuo nas juntas ZrO2/Ti-6Al-4V. Testes de detecção de vazamento de gás hélio foram realizados na interface de união das juntas; amostras removidas na seção transversal de juntas estanques foram examinadas por técnicas de análise microestrutural. Formou-se uma camada escura adjacente à cerâmica metalizada, responsável pelo molhamento ocasionado pela liga Ag-28Cu. Entretanto, o uso da liga Au-18Ni resultou em precipitação de intermetálicos e microtrincamento interfacial. Perfis de microdureza através da interface resultante até onde a zircônia mostrou típico escurecimento não indicaram alternância significativa entre medições consecutivas; os resultados dos ensaios de resistência mecânica à flexão-3p foram considerados satisfatórios.

Microstructure-property relations in composite yttria-substituted zirconia solid electrolytes

A study of composite 8 mol% yttria stabilized zirconia (8YSZ) and 3 mol% yttria tetragonal zirconia polycrystal (3YTZP) solid electrolytes sintered under isothermal and two-step sintering cycles is reported. The nominal phase composition is retained for composites with up to 25 wt.% 3YTZP. These composites show a combination of beneficial effects with respect to pure 8YSZ, including slight improvement in sinterability, gains in bulk and grain boundary conductivity and also enhanced fracture toughness. Impedance spectroscopy revealed an enhancement of the specific grain boundary conductivity for samples with finer grain sizes, attained by increasing the fraction of 3YTZP or by hindering grain growth under two-step sintering cycles. This effect is rationalized in terms of a decrease of the grain boundary space-charge potential. The conductivity gains decrease with increasing temperature, but even at 700 °C the total ionic conductivity of ceramics with 25 wt.% 3YTZP is still higher than that of pure 8YSZ, whereas at 900 °C there is a performance loss of less than 10%. The improved mechanical and electrical performance in the intermediate temperature range represents an important advantage of the heterostructured electrolytes for low/intermediate temperature SOFC operation.

Superplasticity in nanocrystalline ceramics: pure grain boundary phenomena or not?

Abstract Superplasticity in ceramics has been the subject of intense research activity for the last two decades. Quite recently, the fabrication of fully dense nanocrystalline oxides with grain size below 100 nm enabled examination of their superplastic behaviour. This work presents a critical analysis of the plasticity of two important nanostructured oxide systems: MgO and yttria tetragonal zirconia polycrystals. A thorough comparison of their plastic deformation reveals that nano-structuring may be a necessary, but not a sufficient condition for superplasticity in ceramics as commonly assumed. Instead, the changes in the chemical composition and the transport properties, through the bulk and at grain boundaries, versus temperature and grain size can induce a rich variety of mechanical responses.

Reliability and Failure Modes of Implant‐Supported Y‐TZP and MCR Three‐Unit Bridges

Chipping within veneering porcelain has resulted in high clinical failure rates for implant-supported zirconia (yttria-tetragonal zirconia polycrystals [Y-TZP]) bridges. This study evaluated the reliability and failure modes of mouth-motion step-stress fatigued implant-supported Y-TZP versus palladium-silver alloy (PdAg) three-unit bridges. Implant-abutment replicas were embedded in polymethylmethacrylate resin. Y-TZP and PdAg frameworks, of similar design (n = 21 each), were fabricated, veneered, cemented (n = 3 each), and Hertzian contact-tested to obtain ultimate failure load. In each framework group, 18 specimens were distributed across three step-stress profiles and mouth-motion cyclically loaded according to the profile on the lingual slope of the buccal cusp of the pontic. PdAg failures included competing flexural cracking at abutment and/or connector area and chipping, whereas Y-TZP presented predominantly cohesive failure within veneering porcelain. Including all failure modes, the reliability (two-sided at 90% confidence intervals) for a "mission" of 50,000 and 100,000 cycles at 300 N load was determined (Alta Pro, Reliasoft, Tucson, AZ, USA). No difference in reliability was observed between groups for a mission of 50,000. Reliability remained unchanged for a mission of 100,000 for PdAg, but significantly decreased for Y-TZP. Higher reliability was found for PdAg for a mission of 100,000 cycles at 300 N. Failure modes differed between materials.

Evaluation of alumina effects on the mechanical property and translucency of nano-zirconia all-ceramics

To study the effects of alumina content on sintered density, mechanical property and translucency of zirconia nanocomposite all-ceramics. Specimens of zirconia nanocomposite all-ceramics were divided into five groups based on their alumina content which are 0% (control group), 2.5%, 5.0%, 7.5% and 10.0% respectively. The sintered densities were measured using Archimedes' method. Specimens' bending strengths were measured with three-point bending test (ISO 6872). The visible light transmittances were measured with spectrophotometric arrangements and the fractured surfaces were observed using scanning electron microscope (SEM). The control group of pure zirconia could be sintered to the theoretical density under pressure-less sintering condition. The bending strength was (1100.27 ± 54.82) MPa, the fracture toughness was (4.96 ± 0.35) MPa×m(1/2) and the transmittance could reach 17.03%. The sintered density and transmittance decreased as alumina content increased from 2.5% to 10%. However, the fracture toughness only increased slightly. In all four alumina groups, the additions of alumina had no significant effect on samples' bending strengths (P > 0.05). When the content of alumina was 10%, fracture toughness of specimens reached (6.13 ± 0.44) MPa×m(1/2) while samples' transmittance declined to 6.21%. SEM results showed that alumina particles had no significant effect on the grain size and distribution of tetragonal zirconia polycrystals. Additions of alumina to yttria-tetragonal zirconia polycrystals could influence its mechanical property and translucency. Additions of the other phase to zirconia ceramics should meet the clinical demands of strength and esthetics.

Synthesis and sintering of Y 2O 3-doped ZrO 2 powders using two Pechini-type gel routes

Yttria-tetragonal zirconia polycrystal (ZrO 2 + 4.5 mol% Y 2O 3) nanocrystalline powder was synthesized by two Pechini-type gel routes, the in situ polymerized complex (IPC) method and the PEG/AF method. FTIR spectra confirmed coordination of metal ions with the polymer by different routes, depending on the method used. The crystallite size of the powder increased from 5 nm to 8 nm when the temperature was increased from 450 °C to 600 °C and calcination times increased from 2 h to 24 h. The morphology of the powders differed only when the organic impurities were not completely eliminated. After calcination, the morphology of the powders produced by the two methods showed porous agglomerates composed of smaller particles. All the resulting microstructures were very similar, regardless of the method employed to obtain the powder or the calcination times and temperatures.

Grain growth kinetics and segregation in yttria tetragonal zirconia polycrystals

Abstract The aim of this work is the determination of the grain growth kinetic law in 4 mol.% yttria tetragonal zirconia polycrystals. To that purpose, several sets of slices of 4 mol.% yttria tetragonal zirconia polycrystals were annealed for different times at a constant temperature as well as at a constant time for different temperatures. The mean grain size was determined by means of scanning electron microscopy observations of the annealed surfaces, after fitting the grain size distributions to lognormal functions. A power law of the mean grain size versus the annealing time was found to describe the experimental results. Surprisingly, the same power law was shown to account for the dependence of the grain size standard deviations versus time. A correlation of these results with a model reported in the literature on the yttrium segregation to grain boundaries is discussed.

Effect of bovine serum constituents on the surface of the tribological pair alumina/alumina nanocomposites for total hip replacement

Alumina has been widely used in the fabrication of hip joint replacement due to its excellent properties. But one of its drawbacks is the low fracture toughness, which can be enhanced with the addition of a second ceramic phase of nanometer size. Another property to be improved is its wear resistance under severe rubbing conditions. In this work Yttria Tetragonal Zirconia Polycrystal, Y-TZP (TZ-8YS, 100 nm), TiO 2 (PS-25, 50 nm) and Co (Nilaco, 28 nm) were added to Al 2O 3 (AKP 50, 300 nm). These starting powders were mixed and hot pressed, in order to fabricate alumina nanocomposites. Mechanical properties of the nanocomposites were estimated using the indentation method. Wear tests were carried out using a ball-on-plate tribometer, with a frequency of 1 Hz, at a load of 49 N, for 1 h. Alumina balls were used as the counterface. Distilled water and fetal bovine serum solution (FBSS) were the environments. The specific wear rate was within 10 −8 to 10 −7 mm 3/N m and the coefficient of friction was around 0.3–0.7. Keeping in mind that wear is a process that starts on the surface and it is related to the physical chemistry of the surfaces, techniques such as scanning electron microscopy (SEM), and X-ray photoelectron spectrometry (XPS) were used to elucidate the role played by the proteins and phospholipids present in the fetal bovine serum solution and the new chemical specie formed on the surface.