• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.5
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• pp.434-444
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• 2006

This study was performed to evaluate the effects of three different implant surface treatments to the bone formation during osseous healing period under unloading conditions. Machined, double-acid etched and anodic oxidized implants were inserted into tibia of 3.0 - 3.5 kg NZ white male rabbits and 2 animals of each group were sacrificed at 2, 4 and 8 weeks. The specimens containing implant was dehydrated and embedded into hard methylmethacrylate plastic. After grinding to $50{\mu}m$, the specimens were stained with Villanueva bone stain. From each specimen, histomorphometric evaluation and the bone implant contact rate were analysed with optical microscope. The results were as follows; 1. In the scanning electronic microscopic examination, machined surface implant had several shallow and paralleled scratches on plain surface, double acid-etched implant had lots of minute wrinkles, rough valley and also irregularly located craters that looked like waves, anodic oxidized surface implant had porosity that minute holes were wholly distributed on the surface. 2. After 2 weeks of implantation, the percentages of bone-to-implant contact in the machined implant, double acid-etched implant and anodic oxidized implant were 26.85%, 62.64% and 59.82%, after 4 weeks of implantation they were 64.29%, 77.85% and 75.23%, and after 8 weeks they were 82.66%, 85.34% and 86.39%. 3. After 2 weeks of implantation, the percentages of bone area between threads in the machined implant, double acid-etched implant and anodic oxidized implant were 21.55%, 42.81%, and 40.33%, after 4 weeks of implantation they were 49.32%, 62.60% and 75.56%, and after 8 weeks they were 71.62%, 87.73% and 83.94%. In summary, percentages of implant surface contacted to bone trabeculae and bone formation area inside threads in double acid-etched implants and anodic oxidized implants were greater than machined implants in early healing stage. These results suggest that double acid-etched and anodic oxidized surface implants could reduce the healing period for osseointegration and may enable to do early function.

• The Journal of Advanced Prosthodontics
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• v.4 no.1
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• pp.18-23
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• 2012

PURPOSE. The purpose of this prospective study was to evaluate the effect of early loading on survival rate or clinical parameter of anodic oxidized implants during the 12- month postloading period. MATERIALS AND METHODS. Total 69 implants were placed in 42 patients. Anodic oxidized implants (GS II, Osstem Cor., Busan, Korea) placed on the posterior mandibles were divided into two groups, according to their prosthetic loading times: test group (2 to 6 weeks), and control group (3 to 4 months). The implant survival rates were determined during oneyear postloading period and analyzed by Kaplan-Meier method. The radiographic peri-implant bone loss and periodontal parameters were also evaluated and statistically analyzed by unpaired t-test. RESULTS. Total 69 implants were placed in 42 patients. The cumulative postloading implant survival rates were 88.89% in test group, compared to 100% in control group (P<.05). Periimplant marginal bone loss (T: $0.27{\pm}0.54$ mm, C: $0.40{\pm}0.55$ mm) and periodontal parameters showed no significant difference between the groups (P>.05). CONCLUSION. Within the limitation of the present study, implant survival was affected by early loading on the anodic oxidized implants placed on posterior mandibles during one-year follow-up. Early implant loading did not influence peri-implant marginal bone loss, and periodontal parameters.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.339-344
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• 2007

Statement of problem. Various anodic oxidation techniques can be applied to dental implant surfaces. But the condition for optimal anodized surfaces has not been described yet. Purpose. The purpose of this investigation was to compare an implant that was oxidized by another method with $TiUnite^{TM}$ through resonance frequency analysis and histomorphometry. Material and methods. Turned (control), $TiUnite^{TM}$ and another oxidized fixtures, which used $Ca^{2+}$ solution for anodic oxidation, were placed in the tibiae of 5 New Zealand White rabbits. The bone responses were evaluated and compared by consecutive resonance frequency analysis once a week for 6 weeks and histomorphometry after a healing period of 6 weeks. Results. At the first week, both oxidized implants showed significantly higher implant stability quotient (ISQ) values than the control. No significant differences in resonance frequency analysis were found between the two oxidized groups for 6 weeks. The means and standard deviations of bone-to-implant contact (BIC) ratios were $71.0{\pm}4.2$ for $TiUnite^{TM}$, $67.5{\pm}10.3$ for the $Ca^{2+}$-based oxidation fixture, $22.8{\pm}6.5$ for the control. Both oxidized implants were significantly superior in osseointegration to the turned one. There was, however, no statistically significant difference between the two oxidized implants. Conclusion. $TiUnite^{TM}$ and the $Ca^{2+}$-based oxidation fixture showed superior early bone response than the control with respect to resonance frequency analysis and histomorphometry. No significant differences between the oxidized groups, however, were found in this investigation using the rabbit tibia model.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.4
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• pp.349-365
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• 2006

State of problem : A number of investigation about increase of surface area via various surface treatments and modification of surface constituent have been carried out. Purpose : The surface characteristics and stability of implants treated with anodic oxidation, fluoride ion incorporation, and groups treated with both methods were evaluated. Material and method : Specimens were divided into six groups, group 1 was the control group with machined surface implants, groups 2 and 3 were anodic oxidized implants (group 2 was treated with 1M $H_2SO_4$ and 185V, group 3 was treated with 0.25M $H_2SO_4$ and $H_3PO_4$ and 300V). Groups 4, 5 and 6 were treated with fluoride. Group 4 was machined implants treated with 0.1% HF, and groups 5 and 6 were groups 2 and 3 treated with 10% NaF respectively. Using variable methods, implant surface characteristics were observed, and the implant stability was evaluated on rabbit tibia at 0, 4, 8 and 12 weeks. Result : 1. In comparison of the surface characteristics of anodic oxidized groups, group 2 displayed delicate and uniform oxidation layer with small pore size containing Ti, C, O and showed mainly rutile, but group 3 displayed large pore size and irregular oxidation layer with many crators. 2. In comparison of the surface characteristics of fluoride treated groups 4, 5, 6 and non-fluoride treated groups 1, 2, 3, the configurations were similar but the fluoride treated groups displayed rougher surfaces and composition analysis revealed fluoride in groups 4, 5, 6. 3. The fluoride incorporated anodic oxidized groups showed the highest resonance frequency values and removal torque values, and the values decreased in the order of anodic oxidized groups, fluoride treated group, control group. 4. According to implant stability tests, group 2 and 3 showed significantly higher values than the control group (P<.05). The fluoride treated groups showed relatively higher values than the non fluoride treated groups and there were significant difference between group 4 and group 1 (P<.05). Conclusion : From the results above, it can be considered that the anodic oxidation method is an effective method to increase initial bone stability and osseointegration and fluoride containing implant surfaces enhance new bone formation. Implants containing both of these methods should increase osseointegration, and reduce the healing period.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.188-191
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• 2003

In this wort. the effect of anodic oxidation on surface characteristics of high strength PAN-based carbon fibers is investigated in terms of surface and mechanical interfacial properties of the composites. As a result, the acidity of carbon fiber surfaces is increased, due to the development of oxygen functional groups in the presence of anodic oxidation. Also. it is found that the critical stress intensity factor ($K_{IC}$) is improved in the oxidized fibers-reinforced composites. which can be attributed to the good wettability between fibers and epoxy resin matrix.

• Proceedings of the Korean Magnestics Society Conference
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• 1994.03a
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• pp.40-41
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• 1994

• Journal of Surface Science and Engineering
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• v.17 no.2
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• pp.29-40
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• 1984

The structure of rapidly solidified Al-Si-based alloys and its relationship to subsequent anodic film growth in near neutral and acid solutions have been investigated. Solidification of the alloys proceeds via pre-dendritic nuclei, associated with rugosity of the casting surface, from which cellular-type growth, comprised of aluminium-rich material surrounded by silicon-containing material, emanates. Observation of ultramicrotomed sections of the alloys and their anodic films reveals the local oxidation of the silicon-rich phase and its incorporation into the anodic alumina film, formed in near neutral solutions. Such incorporation occurs but resultant isolation of the silicon-rich phase is not possible for anodizing in phosphoric acid, and a three-dimensional network of the oxidized silicon-containing phase, with continuing development of porous anodic alumina, is observed.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1295-1297
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• 1994

At 34 at% Co-Fe, the aluminum anodic oxidized (alumite) films of particle diameter $150{\AA}$ have large perpendicular anisotropy energy and high coercive force. However, for the samples of particle diameter larger than $450{\AA}$, the bottom of each particle forms abnormal part called branch-shaped different from that of particle diameter $150{\AA}$. In this case the magnetic anisotropy energy Ku was about zero at the compositions of 45 and 75 at% Co. Furthermore, at tile compositions from 50 to 70 at% Co, the values of Ku became negative value. We confirmed that Fe-C deposited the bottom of particle orients very strongly and it has a large influence upon the magnetic anisotropy energy.

• Journal of Surface Science and Engineering
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• v.52 no.1
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• pp.1-5
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• 2019

Anodic oxidized $TiO_2$ nanotube arrays are promising materials for application in photoelectrochemical solar cells as the photoanode, because of their attractive properties including slow electron recombination rate, superior light scattering, and smooth electrolyte diffusion. However, because of the opacity of these nanotube electrodes, the back-side illumination is inevitable for the application in solar cells. Therefore, for the fabrication of solar cells with the anodic oxidized nanotube electrodes, it is required to develop efficient and transparent counter electrodes. Here, we demonstrate quantum dot-sensitized solar cells (QDSCs) based on the nanotube photoanode and transparent counter electrodes. The transparent counter electrodes based on Pt electrocatalysts were prepared by a simple thermal decomposition methods. The photovoltaic performances of QDSCs with nanotube photoanode were tested and optimized depending on the concentration of Pt precursor solutions for the preparation of counter electrodes.

• Journal of the Korean Ceramic Society
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• v.28 no.6
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• pp.443-450
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• 1991

Microstructures of tantalum oxide, anodic-oxidized in oxalic acid, are shown to be related to voltage-time characteristics during formation reaction. It is observed that a crystalline phase transformed from an amorphous phase is recrystallized in the presence of the high electric field within the film, and this recrystallized film has a very porous microstructure. From the results of the XRD, the nonlinearity observed after the first spark voltage is recognized to be due to the local crystallization.