• Journal of the Korean institute of surface engineering
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• v.38 no.1
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• pp.37-43
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• 2005

Nanosized titanium-colloid particles were prepared by sol-gel method. The physical properties, such as thermal stability, crystallite size and crystallinity according to synthesis condition have been investigated by TEM, XRD, SEM, TGA and DTA. In addition, Zinc phosphating has been studied in order to compare the phosphating characterization of prepared nanosized titanium-colloid particles. The major phase of all the prepared titanium-colloid particles was an amorphous structure regardless of synthesis temperature and the structure was composed of phoshate complex and titanium. The micrographs of HR- TEM showed that nanosized titanium-colloid particles possessed a spherical morphology with a narrow size distribution. The crystallite size of the titanium-colloid particles synthesized at 80℃ was 4-5 nm and increased to 8-10 nm with an increase of synthesis temperature (150℃). In addition, the coating weight increased with an increase of temperature of phosphating solution and when the concentration of titanium-colloid was 2.0 g/l, the coating weight was 1.0 g/㎡.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.740-750
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• 2006

Statement of problems. In an attempt to reduce screw loosening, dry lubricant coatings such as pure gold or tefron have been applied to the abutment screw. However, under repeated tightening and loosening procedures, low wear resistance and adhesion strength of coating material produced free particles on the surface of abutment screw and increased frictional resistance resulting in screw tightening problems. Purpose. The aim of this study was to compare friction coefficient, adhesion strength, vickers hardness and evaluate coating surface of titanium alloy specimens coated with TiN(titanium nitride), ZrN(zirconium nitride) and WC(tungsten carbide). Material and method. Titanium alloy(Ti-6Al-4V) discs of 12mm in diameter and 1mm in thickness divided into 4 groups. TiN, ZrN and WC was coated for the specimens of 3 groups respectively, and those of 1 group were not coated. Each group was made up of 4 specimens. In this study, sputtering method was used among the PVD(Physical Vapor Deposition) techniques available for TiN, ZrN and WC coatings. Friction coefficient, adhesion strength, vickers hardness and coating surface of 4 groups were measured. Results. 1. For all three coating conditions, friction coefficient was significantly decreased. Especially, ZrN coated surface showed the lowest value. $TiN(0.39{\pm}0.02)$, $ZrN(0.24{\pm}0.01)$, $WC(0.31{\pm}0.03)$. 2. TiN coating showed the highest adhesion strength, however ZrN coating had the lowest value. $TiN(25.3N{\pm}1.6)$, $ZrN(14.8N{\pm}0.6)$, $ WC(18.4N{\pm}0.7)$. 3. Vickers hardness of all three coatings was remarkably increased as compared with that of none coated specimen. TiN coating had the highest Vickers hardness, however WC coating showed the lowest value. $TiN(1865.2{\pm}33.8)$, $ZrN(1814.4{\pm}18.6)$, $WC(1008.5{\pm}35.9)$. 4. The ZrN or WC coated specimen showed a homogeneous and smooth surface, however the rough surface with defects was observed for TiN coating. Conclusions. When TiN, ZrN and WC coating applied to the abutment screw, frictional resistance would be reduced, as a result, the greater preload and prevention of the screw loosening could be expected.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.795-804
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• 2007

Statement of problem. Nano-scale calcium-phosphate coating on the anodizing titanium surface using ion beam-assisted deposition (IBAD) has been recently introduced to improve the early osseointegration. However, not much is known about their surface characteristics that have influence on tissue-implant interaction. Purpose. This study was aimed to investigate microtopography, surface roughness, surface composition, and wettability of the titanium surface modified by the anodic oxidation and calcium phosphate coating using IBAD. Material and methods. Commercially pure titanium disks were used as substrates. The experiment was composed of four groups. Group MA surfaces represented machined surface. Group AN was anodized surface. Group CaP/AN was anodic oxidized and calcium phosphate coated surfaces. Group SLA surfaces were sandblasted and acid etched surfaces. The prepared titanium discs were examined as follows. The surface morphology of the discs was examined using SEM. The surface roughness was measured by a confocal laser scanning microscope. Phase components were analyzed using thin-film x-ray diffraction. Wettability analyses were performed by contact angle measurement with distilled water, formamide, bromonaphtalene and surface free energy calculation. Results. (1) The four groups showed specific microtopography respectively. Anodized and calcium phosphate coated specimens showed multiple micropores and tiny homogeneously distributed crystalline particles. (2) The order of surface roughness values were, from the lowest to the highest, machined group, anodized group, anodized and calcium phosphate deposited group, and sandblasted and acid etched group. (3) Anodized and calcium phosphate deposited group was found to have titanium and titanium anatase oxides and exhibited calcium phosphorous crystalline structures. (4) Surface wettability was increased in the order of calcium phosphate deposited group, machined group, anodized group, sandblasted and acid etched group. Conclusion. After ion beam-assisted deposition on anodized titanium, the microporous structure remained on the surface and many small calcium phosphorous crystals were formed on the porous surface. Nanoscale calcium phosphorous deposition induced roughness on the microporous surface but hydrophobicity was increased.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.36-45
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• 2007

Several features of the implant surface, such as topography, roughness, and composition play a relevant role in implant integration with bone. This study was conducted in order to determine the effects of different-coatings on Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on HA (Hydroxyapatite coating on Titanium), Ano (HA coating on anodized surface Titanium), Zr (zirconium-coating on Titanium), and control (non-coating on Titanium). The morphology of these cells was assessed by SEM. The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1,152 elements). The appearances of the surfaces observed by SEM were different on each of the three dental substrate types. MG63 cells cultured on HA, Ano, Zr, and control exhibited cell-matrix interactions. In the expression of several genes were up-, and down-regulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface morphology of the dental materials used.

• Journal of the Korean institute of surface engineering
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• v.51 no.3
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• pp.164-171
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• 2018

In this study, we have fabricated pure titanium (Ti)/hydroxyapatite (HA) double layer coating on medical grade PEEK from magnetron sputtering system, an investigation was performed whether the surface can be had more improve bio-active for orthopedi/dental applications than that of non-coated one. Pure Ti and HA coating layer were obtained by a radio-frequency and direct current power magnetron sputtering system. The microstructures surface, mechanical properties and wettability of the pure Ti/HA double layer deposited on the PEEK were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), nano-indentation, and contact angle test. According to the EDS and XRD results, the composition and crystal structure of pure Ti and HA coated surface were verified. The elastic modulus and hardness value were increased by pure Ti and HA coating, and the pure Ti/HA double layer coating surface has the highest value. The contact angle showed higher value for pure Ti/HA double layered coating specimens than that of non-coated (PEEK) surface.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.210-225
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• 2004

Statement of problem: Implant screw loosening has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. Purpose : The purpose of this study was to investigate surface characteristics of TiN and ZrN film ion plated screw with titanium and gold alloy screw and to evaluate wear resistance, surface roughness, and film adhesion on screw surface using various instruments. Material and methods : GoldTite screws and titanium screws provided by 3i (Implant Innovation, USA) and TorqTite screws or titanium screws by Steri-Oss (Nobel Biocare, USA) and gold screws and titanium screws by AVANA (Osstem Implant, korea) were selected. Ion plating which is much superior to other surface modification techniques was carried out for gold screws and titanium screws using Ti and Zr coating materials with nitrogen gas. Ion nitrided surface of each abutment screw was observed with field emission scanning electron microscopy (FE-SEM, micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. Results : 1) The surface of gold screw and GoldTite is more smooth than ones of other kinds of non coated screw. 2) The ZrN and TiN coated surface is the more smooth than ones of other kinds of screw. 3) The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. 4) The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. 5) The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw. Conclusion : It is considered that the TiN and ZrN coated screw which would prevent a screw from loosening can be applicable to implant system and confirmed that TiN and ZrN film act as lubricant on surface of screw due to decrease of friction for recycled tightening and loosening.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.748-758
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• 2014

The purpose of this study is to find the optimum conditions for manufacturing titanium dioxide using a hybrid self-assembly forming method, to confirm the shape, properties and synergy effect of UV protection for hybrid titanium dioxide. Hybrid titanium dioxide, manufactured by forming self-assembly of different sizes consisting of two kinds of titanium dioxides, has micro titanium dioxide (250nm~300nm) for support material, Nano titanium dioxide (20~30nm) for surface material, coating support material. Adjustment experiments of $AlCl_3$ concentration and both titanium dioxide ratio were conducted to find the optimized conditions for the surface coating of titanium dioxide striking a negative charge, a sample made of the optimized process was confirmed through an optical analysis, particle size analysis, and potentiometric analysis. The SPF in-vitro value of the cosmetics samples containing hybrid titanium dioxide showed 15~30% higher levels than the cosmetics samples containing both titanium dioxides mixture.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.84-95
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• 2001

Titanium is widely used in dentistry for its low density, high strength, fatigue resistance, corrosion resistance, and biocompatibility. But it has a tendency of surface damage under circumstance of friction and impact for its low hardness of the surface. Coating is one of methods fir increasing surface hardness. Its effect is to improve surface physical characteristics without change of titanium. Diamond-like carbon and titanium nitride are known for its high hardness of the surface. So that this study was aimed at the wear test and the cytotoxicity test of the commercially pure titanium and Ti-6Al-4V alloy which were deposited by diamond-like carbon film or titanium nitride film to acertain improvement of the surface hardness and the biocompatibility. A disk (25mm diameter, 2mm thickness) was made of commercially pure titanium and Ti-6Al-4V alloy and these substrates were deposited by diamond-like carbon film or titanium nitride film. Diamond-like carbon film was deposited by the method of radiofrequency plasma assisted chemical vapor deposition and titanium nitride film was deposited by the method of reactive arc ion plating. Then these substrates were tested about wear characteristics by the pin-on-disk type wear tester in which ruby ball was used as a wear causer under the load of 32N, The fracture cycles were measured by rotating the substrates until their films were fractured. The wear volume was measured after 150 cycles and 3,000 cycles using surface profiler. The cytotoxicity test was peformed by the method of the MTT assay. The results were as follows : 1. In the results of the wear volume test, commercially pure titanium and titanium alloy which were coated by diamond-like carbon film or titanium nitride aim had higher resistance against wear than the substrates which were not coated by any films (P<0.05). 2. In the results of the fracture cycle test and the wear volume test, diamond-like carbon film had higher resistance against wear than titanium nitride film (P<0.05). 3. In both coatings of diamond-like carbon aim and titanium nitride film, Ti-6Al-4V alloy had higher resistance against wear than commercially pure titanium (P<0.05) 4. In the results of the cytotoxicity test, diamond-like carbon film and titanium nitride film had little cytotoxicity as like commercially pure titanium or Ti-6Al-4V alloy (P>0.05).

• Journal of the Korean institute of surface engineering
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• v.27 no.1
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• pp.29-35
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• 1994

The effects of coating of 3$\mu\textrm{m}$ thickness on the mechanical property of alumina after heat treatment at 100$0^{\circ}C$ for 30minutes under $10^{-6}$torr vacuum was quantified in terms of modulus of rupture(MOR) using Weibull plot. While the copper coating did not change MOR of alumina due to the nonwetting behavior of Cu on $Al_2O_3$, the reactive titanium metal coating caused a noticeable 29% reduction in averaged MOr strength. This was related with the combined effects of microcracks in coating formed during heat treatment and good bonding character between Ti and $Al_2O_3$. The effect of cosputtering of Ti and Cu, bilayer coatings of Cu/Ti and Ti/Cu were also investigated. It was found that Ti, cosputtered, Cu/ti and Ti/Cu coatings reduced MOR strength of alumina in the order listed. This was correlated with the amount of Ti at coating/alumina inter-face associated with a coated layer or segregation of Ti during heat treatment.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.392-405
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• 2020

Purpose: Titanium implants are widely used in the treatment of dentition defects; however, due to problems such as osseointegration failure, peri-implant bone resorption, and periimplant inflammation, their application is subject to certain restrictions. The surface modification of titanium implants can improve the implant success rate and meet the needs of clinical applications. The goal of this study was to evaluate the effect of the use of porous titanium with a chitosan/hydroxyapatite coating on osseointegration. Methods: Titanium implants with a dense core and a porous outer structure were prepared using a computer-aided design model and selective laser sintering technology, with a fabricated chitosan/hydroxyapatite composite coating on their surfaces. In vivo and in vitro experiments were used to assess osteogenesis. Results: The quasi-elastic gradient and compressive strength of porous titanium implants were observed to decrease as the porosity increased. The in vitro experiments demonstrated that, the porous titanium implants had no biological toxicity; additionally, the porous structure was shown to be superior to dense titanium with regard to facilitating the adhesion and proliferation of osteoblast-like MC3T3-E1 cells. The in vivo experimental results also showed that the porous structure was beneficial, as bone tissue could grow into the pores, thereby exhibiting good osseointegration. Conclusions: Porous titanium with a chitosan/hydroxyapatite coating promoted MC3T3-E1 cell proliferation and differentiation, and also improved osseointegration in vitro. This study has meaningful implications for research into ways of improving the surface structures of implants and promoting implant osseointegration.