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PubMed1986

Inorganic particulates associated with pulmonary alveolar proteinosis: SEM and X-ray microanalysis results.

Twenty-four cases of pulmonary alveolar proteinosis (PAP) were studied by light microscopy (LM) and scanning electron microscopy (SEM) to test the hypothesis that PAP was related to silica exposure. Increased numbers of birefringent particles (vs. controls) were found in 78% of PAP cases. SEM was used to locate inorganic particulates in situ, which were individually analyzed using energy dispersive X-ray analysis. When analyzed as an aggregate group of cases, no specific inorganic particulate was evidently associated with the PAP reaction. However, analysis of individual cases revealed more specific associations. The concentration of particles determined by SEM exceeded that found by LM by a factor ranging from 2.7 to 964. The concentration of inorganic particulates per cm3 in the areas of PAP ranged from 1.3 X 10(7) to 1.02 X 10(9). Controls all had less than 10(7) particles per cm3. Available environmental history correlated well with particulate analysis results, e.g., silica in a sandblaster, metal fumes in a welder, and cement particles in a cement finisher. Particulates with unique composition were also found in cases with unavailable histories, e.g. metal fumes suggestive of welding or soldering exposure, silicates suggestive of fine particle exposure (greater than 50% of particles less than 1 micron). Only 1 case (the sandblaster) showed greater than 50% of the particles to be silica. Of the 5 infants with PAP, 3 showed the major particulate to be talc, and 1 had evidence of toxic cadmium selenide fume exposure. These results are consistent with the hypothesis that PAP, at least in the majority of cases, is associated with exposure to small inorganic particulates of several types.

Electron Probe Microanalysis↗
PubMed1999

Dispersed polyphosphate in fungal vacuoles in Eucalyptus pilularis/Pisolithus tinctorius ectomycorrhizas.

Ectomycorrhizas produced between Pisolithus tinctorius and Eucalyptus pilularis under axenic conditions were rapidly frozen, freeze-substituted in tetrahydrofuran and embedded anhydrously, and dry-sectioned for X-ray microanalysis. The vacuoles of the sheath and Hartig net hyphae were rich in phosphorus and potassium. They also contained sulfur and variable amounts of chlorine. In anhydrously processed freeze-substituted mycorrhizas, dispersed electron-opaque material filled the fungal vacuoles. X-ray maps indicated that P was distributed evenly throughout the entire vacuole profile and was not concentrated in spherical bodies or subregions of the vacuole. There were no electron-opaque granules surrounded by electron-lucent areas, such as are commonly seen in chemically fixed material. The fungal vacuoles were also rich in K, which similarly gave a signal from the entire vacuolar profile. Such P-rich vacuoles occurred in both the mycorrhizal sheath and Hartig net hyphae. Stained sections of ether-acrolein freeze-substituted mycorrhizas also showed only dispersed material in the fungal vacuoles as, in most cases, did acetone-osmium freeze-substituted material. Precipitation of metachromatic granules by ethanol suggested that large amounts of polyphosphate are stored in these regions under the conditions of our experiments, as well as in the tips of actively growing hyphae of the same fungus. The higher plant vacuoles of ectomycorrhizas gave a much lower signal for K, and P was barely detectable. Much more K was located in the vacuoles of the root exodermal cells than in epidermal cells. The analysis of element distribution between the vacuole and cytoplasm in root cells agrees well with that found for other plant species using other techniques. We conclude that polyphosphate is indeed present in the vacuoles of the fungal cells of these ectomycorrhizas, but that in vivo it is in a dispersed form, not in granules.

Basidiomycota↗
PubMed1974

Electron microscopy and electron probe analysis of mitochondrial cation accumulation in smooth muscle.

The contractile responses to barium and the ultrastructure and ionic composition of mitochondria were studied in vascular smooth muscle. In normal rabbit portal anterior mesenteric vein (PAMV) and main pulmonary artery (MPA) smooth muscle mitochondria were frequently associated with the surface vesicles. The average distance between the outer mitochondrial and inner surface vesicle membrane was 4-5 nm. Ba contractures of MPA were tonic and of PAMV were phasic. Incubation of MPA and PAMV with Ba resulted in the accumulation of mitochondrial granules, followed in the MPA by massive mitochondrial swelling. Oligomycin and anoxia inhibited the appearance of mitochondrial electron-opaque granules and prevented the Ba-induced mitochondrial swelling in the MPA. Electron probe analysis of mitochondria in PAMV incubated with Ba and containing granules showed characteristic Ba signals over the mitochondria. Electron probe X-ray microanalysis also showed a highly significant (P < 0.001) correlation of P with mitochondrial Ba, in an estimated elemental ratio of approximately 3 Ba/4 P. Mitochondrial granules were still prominent after block staining of the osmium-fixed, Ba-loaded PAMV, but electron probe microanalysis showed no Ba, but only U, emissions. Tissues incubated with strontium had electron-opaque mitochondrial granules and deposits in the sarcoplasmic reticulum. X-ray microanalysis of mitochondria containing granules showed the presence of characteristic Sr and Ca emissions. The presence of Sr was similarly verified in the sarcoplasmic reticulum. These findings indicate the energy dependent uptake of divalent cations, in association with phosphate, by mitochondria in vascular smooth muscle in situ and the possibility that mitochondria may contribute to the regulation of intracellular divalent cation levels in smooth muscle.

Animals↗
PubMed1997

Apatite layer-coated titanium for use as bone bonding implants.

For development of thin bioactive coatings on metal implants, a dense and uniform apatite layer was coated onto titanium (Ti) implants in situ by using a new biomimetic method, which is composed of apatite nucleation and growth steps in simulated body fluid (SBF). Analysis of the coatings by thin film X-ray diffraction and scanning electron microscopy-energy dispersive X-ray microanalysis (SEM-EMPA) before implantation showed that its characteristics were very similar to those of natural bone. The coated and uncoated rectangular plates were bilaterally implanted into the tibial proximal metaphyses of rabbits. After 6, 10 and 25 weeks post-implantation, the bone bonding and bone formation at the bone-implant interfaces were evaluated by a detachment test and undecalcified histological examination. Mechanical testing in tension showed that the failure load of apatite layer-coated Ti implants was significantly higher than that of uncoated control at each time period (all P < 0.001). Histologically, it was shown that bone was deposited directly onto the apatite coating without any intervening soft tissue, while in the paired controls, interpositional soft tissue was seen at the bone-implant interface. By SEM-EPMA, a uniform calcium- and phosphorus-rich layer was detected between the coated implants and bone, but not in uncoated controls at either earlier or later time periods. The results indicate that the apatite layer deposited on Ti in situ may significantly increase the bone bonding strength by providing a bioactive surface, which allows for an early bone apposition to the implant. In addition, the apatite layer-coated Ti produced by the biomimetic process may fulfil the requirements of favourable thin coatings and strong adhesion at the metal-coating interface.

Analysis of Variance↗
PubMed1988

Energy-dispersive X-ray microanalysis of air-dried microdroplets containing a macromolecular solute.

In the preparation of microdroplets of biological fluids for X-ray microanalysis, we have found that incorporation of a macromolecular solute, dextran, to a final concentration of 1.5-2.5% retards crystal formation and produces sufficiently uniform deposits on thin films to allow droplets to be analysed without prior freeze-drying. Analyses have been carried out at 20 kV in a scanning electron microscope, using energy-dispersive spectrometry. Absorption of Na X-rays by the added solute can be significant but its effect is minimized by preparing droplets as thin as possible, and by using standards of similar composition. The minimum detectable concentrations are increased because of the extra background contribution, and for a single determination are about 6 mM for Na and 2 mM for Cl and K. These concentrations can be further reduced by measuring replicates. The reproducibility of analysis is significantly improved (to less than 5% for Na and K) over the use of calibration curves by calculating the element concentrations from a known element in the sample, chlorine. Under our analytical conditions loss of Cl did not occur. This method requires that the Cl is measured separately by microcoulometry, but eliminates the need for a range of standard droplets on the grid, and determination of the unknowns is then independent of droplet volume, beam current, counting time and magnification. We have compared, with biological samples, the results from using Cl as an internal standard with those obtained using an added standard element, cobalt. The reproducibility using Cl was approximately two-times better than that obtained with Co, probably because of unavoidable volumetric errors when the Co is pipetted separately.

Calcium↗
PubMed2000

A methodological study for the analysis of apatite-coated dental implants retrieved from humans.

The stability of thermally processed hydroxyapatite coatings for oral and orthopedic bioprostheses has been questioned. Information on the chemical changes, which occur with hydroxyapatite biomaterials post-implantation in humans, is lacking. The purpose of this investigation was to begin to examine post-implantation surface changes of hydroxyapatite-coated implants using scanning electron microscopy (SEM), x-ray microanalysis (EDAX), Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD). Three retrieved dental implant specimens from humans following clinical failure due to peri-implantitis were examined. Unimplanted cylinders served as controls. Clinically, the retrieved specimens were all enveloped by a fibrous tissue capsule with bone present at the apical extent of the implant. SEM analysis showed that the retrieved surfaces were coated with both calcified and proteinaceous deposits. EDAX scans of the retrieved specimens demonstrated evidence of hydroxyapatite coating loss reflected by increasing titanium and aluminum signals. Other foreign ions such as sodium, chloride, sulfur, silica, and magnesium were detected. XRD of the control specimens showed that the samples were predominantly apatite; however, two peaks were detected in the diffraction pattern, which are not characteristic of hydroxyapatite, indicating that small amounts of one or more other crystalline phases were also present. The retrieved specimens showed slightly larger average crystal size relative to the control sample material, and the non-apatite lines were not present. FTIR evaluation of the retrieved specimens revealed the incorporation of carbonate and organic matrix on or into the hydroxyapatite. Narrowing of and increased detail in the phosphate peaks indicated an increase in average crystal size and/or perfection relative to the controls, as did the XRD results. Based on these results, we conclude that chemical changes may occur within the coating, with the incorporation of carbonate and concomitant reduction in hydroxyapatite coating thickness. Thermodynamic dissolution-reprecipitation of the coating itself and subsequent surface insult by bacterial and local inflammatory components may be involved with these changes.

Aluminum↗
PubMed2005

Winter urban air particles from Rome (Italy): effects on the monocytic-macrophagic RAW 264.7 cell line.

Epidemiological data show an association between exposure to elevated levels of particulate matter (PM), in particular the fine fraction (<2.5 microm in diameter), and an increase in cardiovascular mortality and respiratory symptoms. The aim of this study was to compare the in vitro toxicity of coarse and fine particulate matter collected with a cascade impactor during winter in an urban area of Rome in relation to their physicochemical characterization (size distribution and chemical composition) as assessed by analytical electron microscopy (SEM/EDX). The X-ray microanalysis data of single particles of coarse and fine matter were analyzed by hierarchical cluster analysis to determine the principal component of the two granulometric fractions. The main chemical difference between the two fractions was the greater abundance of carbonaceous particles in the fine fraction. We compared the ability of coarse and fine fractions, carbon black (CB), and residual oil fly ash (ROFA) to induce arachidonic acid release and tumor necrosis factor-alpha (TNF-alpha) production in the monocytic-macrophagic RAW 264.7 cell line at concentrations of 30 and 120 microg/mL. Our results showed that CB and ROFA were consistently less effective than both fractions of urban particles at inducing an inflammatory reaction in RAW 264.7 cells. Both PM fractions dose-dependently increased TNF-alpha production in RAW 264.7 cells after 5 and 24h of incubation, and only the TNF-alpha production induced by coarse particles at 30 microg/mL decreased significantly (P<0.01) after 24h of treatment. In our in vitro model the winter fine fraction was more reactive than the winter coarse fraction, in contrast to a previously examined summer sample. In the summer sample, coarse particles produced higher levels of inflammatory mediators than fine particles and the CB was consistently less effective than the urban particles. The different behaviors between summer and winter urban fractions may be due to their different physicochemical characteristics; in fact, the comparison of the two samples' characterization by SEM/EDX and X-ray photoelectron spectroscopy (XPS) analysis showed that in winter the carbonaceous particles are more abundant than in summer and that winter particles carry a greater quantity of organic compounds. We suggest that the higher concentration of organic compounds on fine carbonaceous particles may partially explain the higher activation of RAW 264.7 cells by fine particles.

Air Pollutants↗
PubMed1989

Tissue and ultrastructural localization of 5-hydroxytryptamine (serotonin) in the tissues of Ascaris suum with energy dispersive X-ray spectrometry of immunoreactive structures.

Muscle, hypodermis and gastrointestinal epithelial cells from adult female Ascaris lumbricoides var. suum were found to contain serotonin based upon glyoxylic acid induced histofluorescence and indirect immunolabeling with an antiserotonin monoclonal antibody conjugated to protein A-colloidal gold. Histofluorescence indicated that muscle-hypodermis and intestinal epithelial cells contained significant concentrations of 5-hydroxytryptamine while fluorescence was absent in the nerve cord and cuticle. Immunolabeling at the ultrastructural level indicated that serotonin was sequestered in electron-opaque patches, dense vesicles and mitochondria of the muscle-hypodermis and intestinal tissue. Perfusion of whole worms and isolated tissues with 10(4) M-serotonin further indicated: (1) immunolabeled patches and dense vesicles were often associated with cytoskeletal elements, (2) serotonin did not appear to enter the intestinal or muscle cells by endocytosis, (3) immunolabeled patches examined with energy dispersive X-ray spectrometry (X-ray microanalysis) were found to contain iron at concentrations approximately double that of the surrounding cytoplasm.

Animals↗
PubMed1997

The effect of in vitro modeling conditions on the surface reactions of bioactive glass.

Using one parametric variation in solution composition, this paper documents that the surface reactions on bioactive glass (BG) 45S5 are exquisitely dependent upon the modeling conditions. The solutions used were 0.05 M tris hydroxymethyl aminomethane/HCl (tris buffer), tris buffer complemented with plasma electrolyte and/or serum, and serum. The reacted surfaces were analyzed using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDXA), and Rutherford backscattering spectroscopy (RBS). Post-immersion solutions were analyzed for changes in Ca and PO4 concentrations. After a short immersion (3 h), a crystalline, carbonated hydroxyapatite (c-HA) layer formed only in tris. Reaction surfaces of different structure, morphology, and composition were observed after various short and longer term immersions in all other solutions. They comprised two layers with the layer in contact with the bulk consisting mainly of Si; the outer layer, composed of Si, Ca, and P, was amorphous, and had a Ca/P ratio of about 1. Serum proteins adsorbed on the BG surfaces at the early stages of the solution-mediated BG reactions. Formation of a crystalline c-HA layer was delayed up to three or more days in solution with plasma ions. In the presence of serum, only amorphous surfaces composed of Si, Ca, and P were observed for any time up to seven days of immersion. The present data suggest that serum proteins adsorb in tandem with the occurrence of solution-mediated reactions leading to formation of a silica-gel. Amorphous Ca-P phases accumulate in the Si-rich matrix. Furthermore, the present data, in conjunction with the data published before, suggest that physicochemical and cell-mediated reactions occur in parallel to form the glass-tissue interfacial layer.

Biocompatible Materials↗
PubMed1998

Variation of oxide films on titanium induced by osteoblast-like cell culture and the influence of an H2O2 pretreatment.

Variations of titanium oxide films induced by osteoblast-like cells in a rat calvaria culture system and the influence of an H2O2 pretreatment have been investigated by using X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. For abraded titanium, the results revealed that phosphate and calcium ions may incorporate into the surface oxide film during the cell culture, forming a precipitate with a Ca/P ratio near that of hydroxyapatite. Oxidized carbon also was found in the surface layer, most likely precipitated hydroxylcarbonated apatite (HCA). The H2O2 pretreatment of titanium in a phosphate-buffered saline solution results in a 10-fold thickened porous oxide film and large amounts of surface hydroxyl groups as well as a certain amount of phosphate ions inside the oxide film. During the cell culture, the H2O2-treated titanium surface favors the ion incorporation and precipitation of the HCA-like compound, which probably is inlaid into the oxide film. Osteoblast-like cells on the H2O2-treated titanium showed a more active morphology during the initial stage compared with cells on abraded titanium. Moreover, bone-like nodule formation and mineralization appear to be related to the precipitation of the HCA-like compound on the surface. The results are discussed with respect to corrosion resistance, ion incorporation and precipitation of the HCA-like compound on the surface, osseointegration, and bioactivity of titanium implants.

Animals↗
PubMed1998

Effect of surface treatment on unalloyed titanium implants: spectroscopic analyses.

Surgical implant finishing and sterilization procedures were investigated to determine surface characteristics of unalloyed titanium (Ti). All specimens initially were cleaned with phosphoric acid and divided into five groups for comparisons of different surface treatments (C = cleaned as above, no further treatment; CP = C and passivated in nitric acid; CPS = CP and dry-heat sterilized; CPSS = CPS and resterilized; CS = C and dry-heat sterilized). Auger (AES), X-ray photoelectron (XPS), and Raman spectroscopic methods were used to examine surface compositions. The surface oxides formed by all treatments primarily were TiO2, with some Ti2O3 and possibly TiO. Significant concentrations of carbonaceous substances also were observed. The cleaning procedure alone resulted in residual phosphorus, primarily as phosphate groups along with some hydrogen phosphates. A higher percentage of physisorbed water appeared to be associated with the phosphorus. Passivation (with HNO3) alone removed phosphorus from the surface; specimens sterilized without prior passivation showed the thickest oxide and phosphorus profiles, suggesting that passivation alters the oxide characteristics either directly by altering the oxide structure or indirectly by removing moieties that alter the oxide. Raman spectroscopy showed no crystalline order in the oxide. Carbon, oxygen, phosphorus, and nitrogen presence were found to correlate with previously determined surface energy.

Electron Probe Microanalysis↗
PubMed1998

Surface characterization and biological properties study of silicone rubber membrane grafted with phospholipid as biomaterial via plasma induced graft copolymerization.

Poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) was grafted onto the surface of a silicon rubber (SR) membrane (pMPC-SR) by plasma induced grafted copolymerization (PIP). Argon plasma was used to activate the SR surfaces. Determination was also made of the influences of grafted copolymerization reaction time, reaction temperature, and monomer concentration on polymerization yield. The surface properties of SR were characterized by ATR-FTIR, ESCA, and SEM. In those analyses the ATR-FTIR spectra indicated that the pMPC grafted onto the SR surface at 1720 and 3300 cm(-1). The elemental composition and different carbon bindings on the surface of the SR were examined by ESCA. An increasing P1s/C1s value g was obtained in the grafted polymerization yield with a concentration of 0.05-0.5M of MPC in the isolated ethanol solution. The surface morphologies of pMPC-SR differed more than those of control and Ar plasma treated surfaces. The difference could have been caused by the homogeneous graft polymerization of pMPC onto the SR membrane. In the biological analyses, protein adsorption on pMPC-SR surfaces was reduced. The reduced level increased with an increase in the pMPC grafted amount. The epithelial cell attachment and growth onto these samples were suppressed. The blood compatibility for a series of pMPC-SR surfaces was examined by platelet adhesion. Blood platelet morphologies in contact with the high ratio of pMPC-SR surfaces were maintained, meaning that in this case the release reaction for platelets never occurred. Consequently, the high amount of pMPC-SR surface had excellent blood compatibility, further suggesting that prevention of adhesion, activation of platelets, and adsorption of blood protein could be achieved.

Animals↗
PubMed1982

Electron-optical microscopic study of incipient dental microdamage from experimental seed and bone crushing.

No living analogue exists for the hypothetical early hominid hard/tough-seed, coarse-root-eating, and bone-crushing masticatory adaptation. To investigate possible microdamage/microwear to dental enamel caused by such usage, puncture-crushing experiments were carried out on single human teeth, using an Instron compression apparatus on the following six test materials: Makapansgat Limeworks chert (e.g., taphonomy), fresh steer longbone, mongongo nuts, Grewia berries, Carob beans, and wild-onion bulbs. Pairs of extracted unworn third molars were utilized, with one tooth acting as the control. The teeth were mounted, ultrasonically cleaned, and two-stage replicas made with a vinyl polysiloxane elastomer and araldite epoxy resin. After Instron loading and materials failure (1.2-395.0 kg) the test items and the crowns were prepared for comparison with scanning electron microscopy and dispersive x-ray elemental analysis and mapping. The results revealed that although grit adhering to food item surfaces caused microscratches (0.1-1.0 micron wide) similar in appearance to those caused by opal phytoliths in grasses, the dicotyledonous seed coats per se were unable to score enamel. This suggests microscratch morphology alone may not provide a reliable indication of food type. In some cases puncture-crushing of bone and hard legumes produced a localized microfracture pattern (crazing with cracks less than or equal to 0.1-1.0 micron wide) that was readily distinguishable from the simulated taphonomic damage caused by chert fragments, suggesting only analysis of enamel mistaphonomic damage caused by chart fragments, suggesting analysis of enamel microfracture patterns may provide clues as to early hominid dietary adaptations.

Bone and Bones↗
PubMed1986

Adipocyte development in primary rat cell cultures: a scanning electron microscopy study.

This study utilized scanning electron microscopy (SEM) techniques to observe primary cultures of stromal-vascular (SV) cells derived from postnatal rat inguinal adipose tissue. Cells were grown on collagen-coated, fibronectin-coated, or uncoated glass coverslips. Coverslips were normally fixed in glutaraldehyde, osmium tetroxide, dehydrated, and critical-point-dried. Other coverslips were frozen in isopentane (cooled in LN2) and dried or fixed in Baker's formalin for demonstration of inosine diphosphatase (IDPase) by X-ray microprobe analysis (XRMA). Adipocyte morphologies were similar on all substrates. At 2 days of culture, actin cables were detected extending from developing adipocytes. No difference in actin cable structure, cellular shape, or lipid accumulation was observed among the different substrates. Some stromal cells did not accumulate lipid but proliferated into a multilayer by 9 days in culture. Inosine diphosphatase was detected in the Golgi apparatus of developing adipocytes utilizing the technique of XRMA. This study demonstrates the potential for using SEM and XRMA techniques to define morphological features and cytochemical markers of adipocytes in vitro and the response of primary cultured rat SV cells to other attachment substrates.

Adipose Tissue↗
PubMed2002

Use of Ti-coated replicas to investigate the effects on fibroblast shape of surfaces with varying roughness and constant chemical composition.

A two-stage replica technique with a subsequent titanium (Ti)-coating treatment was used to faithfully replicate topographies of polished, acid-etched, machined-like, finely blasted, coarsely blasted, coarsely blasted and acid-etched, and Ti plasma-sprayed Ti surfaces. The replicas were used to study the influence of different rough surface topographies on the response of human fibroblasts in vitro under conditions of constant surface chemistry for all surfaces. The surface topographies of the replicas were characterized using non-contact laser profilometry, scanning electron microscopy (SEM), and stereo-SEM, whereas surface chemistry was examined using X-ray photoelectron spectroscopy. Fibroblasts were trypsinized and plated onto the Ti-coated epoxy-resin replica surfaces for 24 h and observed with SEM. Fluorescein-5-thiosemicarbazide was used to stain the cell components including cell membrane, and the stained cells were optically sectioned using epifluorescent microscopy. The optical sections were computationally reconstructed to obtain three-dimensional images and cell volume and cell thickness determined. The different surface topographies were found to alter cell thickness and cell morphology. However, cell volume as computed from three-dimensional reconstructions was not affected by surface features. The results suggest that cells distort themselves to accommodate to rough surfaces but their volume is not significantly altered.

Cell Size↗
PubMed2002

Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy analysis of titanium surfaces cultured with osteoblast-like cells derived from human mandibular bone.

Variations in the oxide films on titanium surfaces blasted with TiO(2) particles of various sizes were analyzed after cultures with cells derived from human mandibular bone. Turned titanium surfaces and surfaces blasted with 63-90-, 106-180-, and 180-300-microm TiO(2) particles were cultured with osteoblast-like cells. The surfaces were characterized before and after the cell culture with electrochemical impedance spectroscopy (EIS). The surface chemical composition of selected samples was analyzed with X-ray photoelectron spectroscopy (XPS). EIS revealed that with respect to the turned surfaces, the effective surface area was about 5, 6, and 4 times larger on the surfaces blasted with 63-90-, 106-180-, and 180-300-microm particles, respectively. After 28 days of the cell culture, the corrosion resistance on all sample types was unaffected. The impedance characteristics suggest a considerable effect of ion incorporation and precipitation during culturing. XPS revealed that before the cell culture, a typical surface layer consisted of TiO(2). After the culture, the surface oxide film contained both phosphorus and calcium, along with large amounts of oxidized carbon (carbonate) and nitrogen. There were lower concentrations of carbon and nitrogen on the blasted surfaces. We concluded that the effective surface area was several times higher on blasted surfaces than on turned surfaces. Cells derived from human mandibular bone affected ion incorporation into the implant surface.

Cells, Cultured↗
PubMed1995

Bone-bonding behavior under load-bearing conditions of an alumina ceramic implant incorporating beads coated with glass-ceramic containing apatite and wollastonite.

Alumina ceramic with a porous surface coated with glass-ceramic containing apatite and wollastonite (AW-GC) was implanted in a state of press-fit under load-bearing conditions in the femoral condylus of the mongrel dog and compared with a non-glass-ceramic-coated alumina ceramic. A trapezoid alumina ceramic implant (7 x 10 x 5 mm) with a lateral recess (0.9 mm deep) coated with alumina ceramic beads (mean diameter, 750 microns) in a single layer was prepared. The alumina ceramic beads were bonded to the alumina ceramic substratum using an identical alumina binder. The thickness of coating was 10-50 microns (mean, 30 microns). The surface of the beads and the substratum of the alumina implant were coated with AW-GC. A pull-out test and histologic examination were performed at 4, 8, and 24 weeks after implantation. The interfacial shear load was significantly increased from 8 to 24 weeks in both groups. The shear load of the glass-ceramic-coated implant was significantly greater than that of the noncoated implant at every stage. The interface shear load of the noncoated implant was 12.13 +/- 2.76 kg at 4 weeks, 13.92 +/- 4.18 kg at 8 weeks, and 24.17 +/- 5.17 kg at 24 weeks after implantation. The interface shear load of the glass-ceramic-coated implant was 17.96 +/- 2.81 kg at 4 weeks, 24.92 +/- 9.87 kg at 8 weeks, and 34.83 +/- 4.12 kg at 24 weeks after implantation. Histologic examination showed more ingrown bone tissue in the glass-ceramic-coated implants. It is suggested that AW-GC stimulated the bone ingrowth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗