• 한국재료학회지
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• 제23권7호
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• pp.353-358
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• 2013

To improve coating ability and the life of the coating, Ti based composite materials with hydroxyapatite(HA) should be developed. The raw materials of Ti-26wt%, Nb-1wt%, and Si with 10wt% HA were mixed for 24 h by a mixing machine and milled for 1 h to 6 h by planetary mechanical ball milling. Ti-26%Nb-1%Si-(10%HA) composites, composed of nontoxic elements, were fabricated successfully by spark plasma sintering(SPS) at $1000^{\circ}C$ under 70MPa. The relative density of the sintered Ti-Nb-Si-HA composites using the 24 h mixed powder, and the 6 h milled powder, was 91% and 97 %, respectively. The effects of HA contents and milling time on microstructure and mechanical properties were investigated by SEM and hardness tester, respectively. The Vickers hardness of the composites increased with increasing milling time and higher HA content. The Young's modulus of the sintered Ti-26%Nb-1%Si-10%HA composite using the 6 h-milled powder was 55.6 GPa, as obtained by compression test. Corrosion resistance of the Ti-26wt%Nb-1wt%Si composite was increased by milling and by the addition of 10wt%HA. Wear resistance was improved with increasing milling time. Biocompatibility of the Ti-Nb-Si alloys was improved by the addition of HA.

• 한국표면공학회지
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• 제29권6호
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• pp.695-702
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• 1996

Plasma spraying process was employed to produce HA coating on Ti6A14V alloy for the development of a dental implant. The goal of this research was to find optimum spraying conditions for HA coating on Ti6Al4V. This study was thus designed carefully to evaluate how spraying parameters affect various physical properties of a HA coating layer, such as phase composition and bond strength. In plasma spraying, spraying parameters such as hydrogen flow rates and spraying distances were varied systematically to change the degree of the melting of starting HA powder in plasma jet. It was revealed that the deposition efficiency increased with increasing a hydrogen flow rate, and the bond strength between the HA-coated layer and Ti-alloy substrate increased with hydrogen flow rate, but decreased with spraying distance. Therefore, the hydrogen flow rate and the spraying distance should be carefully controlled to obtain the reasonable bond strength simultaneously.

• 대한치과보철학회지
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• 제49권4호
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• pp.333-340
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• 2011

연구 목적: 이 연구의 목적은 수산화인회석 코팅 결정도가 조골세포의 분화에 미치는 영향을 조사하기 위함이다. 연구 재료 및 방법: 제작된 모든 시편은 양극산화과정을 거치면서 티타늄 표면에서 산화막을 형성하여 표면 거칠기를 증가시켰고 각 시편의 표면을 IBAD (ion beam-assisted deposition) 시스템을 이용하여 HA (hydroxyapatite) 코팅하였다. HA의 코팅이 완료된 시편들은 전기가열로(AJ-SB3, AJEON Heating Industrial Co., Ltd, Seoul, Korea)에 넣어 각 실험군별로 $100^{\circ}C$, $300^{\circ}C$, $500^{\circ}C$, $800^{\circ}C$까지 온도를 상승시켜 열처리하였다. HA 코팅을 실시하지 않은 군은 대조군으로 설정하고(control) 소결된 각각의 그룹은 HA100, HA300, HA500, HA800으로 구분하여 설정하였다. 시편 표면의 물리적 성질은 표면 거칠기 테스트, XRD, SEM으로 평가되었다. 수산화인회석 코팅의 결정도의 효과는 조골세포의 분화에 의해 연구되었는데 1, 3, 5, 7일 후에 평가되었다. 성장과 분화 역학은 세포증식능평가, ALP (alkaline phosphatase) 활성능 평가에 의해 조사되었다. 결과: 표면 거칠기는 양극산화 처리 후 IBAD 방식으로HA를 코팅하여도 그 거칠기에는 별 다른 차이가 없음을 보였다. X선 회절분석 결과 $100^{\circ}C$와 $300^{\circ}C$에서 소결한 시편은 HA의 결정화가 없는 무정형상태이며 $500^{\circ}C$와 $800^{\circ}C$에서 소결한 시편의 HA에서는 결정화 상태가 나타났다. 표면에 배양된 조골 세포의 증식능을 측정한 결과 1일과 3일에서는 각 실험군간의 유의할만한 차이가 있었으나, 5일과 7일에는 각 대조군과 실험군 모두 유의성 있는 차이를 보이지 않았다. ALP 활성능은 HA100과 HA300보다 HA500과 HA800이 더 높았다. 결론: 본 연구의 결과에서 양극산화처리된 티타늄표면에 이온빔보조증착법을 이용하여 수산화인회석을 코팅 후 소결할 때 $500^{\circ}C$의 소결온도가 수산화인회석코팅층의 결정화와 HOS (human osteosarcoma cells) 세포의 증식과 분화에 효과가 좋은 것으로 나타났다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 추계학술발표대회
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• pp.41.1-41.1
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• 2009

Aerosol Deposition (AD) is anovel way to fabricate bioactive ceramic coatings in biomedical implants and prostheses applications. In the present work, silicon-substituted hydroxyapatite (HA) coatings on commercially pure titanium were prepared by aerosol deposition using Si-HA powders. The incorporation of silicon in the HA lattice is known to improve the bioactivity of the HA, makingsilicon-substitute HA an attractive alternative to pure HA in biomedical applications. Si-HA powders with the chemical formula $Ca_{10}(PO_4)_6-x(SiO_4)x(OH)_2-x$, having silicon contents up to x=0.5 (1.4 wt%), were synthesized by solid-state reaction of $Ca_2P_2O_7$, $CaCO_3$, and $SiO_2$. The Si-HA powders were characterized by X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF), and Fourier transform infrared spectroscopy(FT-IR). The corresponding coatings were also analyzed by XRD, scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA). The results revealed that a single-phase Si-HA was obtained without any secondary phases such as $\alpha$- or $\beta$-tricalcium phosphate (TCP) for both the powders and the coatings.The Si-HA coating was about $5\;{\mu}m$ thick, had a densemicrostructure with no cracks or pores. In addition, the proliferation and alkaline phosphatase (ALP) activity of MC3T3-E1 preosteoblast cells grown on the Si-HA coatings were significantly higher than those on the bare Ti and pure HA coating. These results revealed the stimulatory effects induced by siliconsubstitution on the cellular response to the HA coating.

• The Journal of Advanced Prosthodontics
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• 제10권2호
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• pp.85-92
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• 2018

PURPOSE. This research evaluated clinical outcomes of two types of hydroxyapatite (HA)-coated implants: OT (Osstem TS III-HA, Osstem implant Co., Busan, Korea) and ZM (Zimmer TSV-HA, Zimmer dental, Carlsbad, USA). MATERIALS AND METHODS. The research was conducted on 303 implants (89 of OT, 214 of ZM), which were placed from January 16, 2010 to December 20, 2012. The prognosis was evaluated in terms of success rates, survival rates, annual marginal bone loss, and implant stability quotients (ISQ). The samples were classified into immediate, early, conventional, and delayed groups according to the loading time. RESULTS. Overall, there were no significant differences between OT and ZM in success rates, survival rates, and annual marginal bone loss, except for the result of secondary stability. OT showed $77.83{\pm}8.23ISQ$, which was marginally higher than $76.09{\pm}6.90ISQ$ of ZM (P<.05). In terms of healing periods, only immediate loading showed statistically significant differences (P<.05). Differences between OT and ZM were observed in terms of two indices, the annual marginal bone loss ($0.17{\pm}0.58mm/year$ < $0.45{\pm}0.80mm/year$) and secondary stability ($84.36{\pm}3.80ISQ$ > $82.48{\pm}3.69ISQ$) (P<.05). OT and ZM did not have any statistically significant differences in early, conventional, and delayed loading (P>.05). CONCLUSION. OT (97.75%) and ZM (98.50%) showed relatively good outcomes in terms of survival rates. In general, OT and ZM did not show statistically significant differences in most indices (P>.05), although OT performed marginally better than ZM in the immediate loading and 1-stage surgery (P<.05).

• Molecular & Cellular Toxicology
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• 제3권1호
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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.

• 대한치과보철학회지
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• 제38권5호
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• pp.659-674
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• 2000

A large increase in the use of thin film coating of hydroxyapatite(HA) in implant dentistry is driven by the desire to take advantage of the excellent biocompatibility and high strength of HA coating. The purpose of this study was to evaluate the effects of HA-coated implants by ion Beam Assisted Deposition(IBAD) method in comparison to the sand-blasted and machined surfaces. Osteoblast culture test, removal torque test and histomorphometric analysis were performed and the following results obtained; 1. Examination of the osteoblast cultures displayed no difference in the secretion of alkaline phosphatase between the various specimen, but IBAD with pure HA specimen showed low alkaline phosphatase secretion(p<0.05). 2. Removal torque tests showed HA-coated implants by IBAD method to be similar in high value to the implants with sand-blasted surface than the implants with machined surface. And the ovariectomized group showed low mechanical test value than the normal group(p<0.05). 3. Histomorphometrical comparisons were performed on undecalcified ground sections. HA-coated implants by IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and 3-best consecutive threads, and the implants with sand-blasted surface and implants with machined surface was in the next consecutive order(p<0.05). HA-coated implants showed slightly higher bone-to- metal contact ratio than sand-blasted implants, but no statistically significant difference was obtained between the two materials. The ovariectomized group showed lower value of bone-to-metal contact ratio than the normal group, but no statistically significant difference was obtained between the two groups. 4. Evaluation of bone volume on all threads and 3-best consecutive threads showed no statistically significant difference among the different surface treatment groups, but showed lower bone volume in ovariectomized group than in the normal group(p<0.05). According tn these results, thin film coated implants with HA showed high bone contact ratio, bone volume and removal torque strength in the short term, but long term observation is needed.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.625-641
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• 2003

Background: This study presents a biomechanical and histometric comparison of bone response to implants with various area of hydroxyapatite(HA) coating. Methods: The implants were placed in the tibia of 10 rabbits weighing 2.5-3.5kg. The control group had a machined surface, the experimental group 1 had 50${\mu}m$ thick HA coated in a band form, and the experimental group 2 had 50${\mu}m$ thick HA coated on the entire surface. 8 weeks after implantation, the animals were sacrificed. Removal torque was measured and histologic preparation was also performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. ANOVA post hoc, and t-test were used for statistical analysis with p-value p<0.05. Results: 1. The removal torques were 9.36${\pm}$5.64 Ncm, 48.40 ${\pm}$ 16.66 Ncm, and 82.37${\pm}$22.56 Ncm for the control, exp. 1, and exp. 2 group respectively. Statistically significant difference were found among all the groups(p<0.05). 2. Bone to implant contact in the cortical bone were 38.94${\pm}$10.9 %, 66.90${\pm}$14.1 %, 73.00${\pm}$19.4 %, in the marrow bone, 8.30${\pm}$5.4%, 14.59${\pm}$5.9%, 18.54${\pm}$11.8%, and in total, 22.40${\pm}$10.1%, 31,17${\pm}$7.5%, 41.41${\pm}$12.2% for the control, exp. 1, and exp. 2 group respectively . In the cortical bone, exp. 1, and exp. 2 group showed statistically significantly higher contact compared to control group. Total contact and in the marrow bone, only exp. 2 group showed statistically significantly higher contact compared to control group(p<0.05). In all the groups significantly higher contact were observed in the cortical bone compared to the marrow bone(p<0.05). 3. Percentage of bone area inside threads in the cortical bone were 55.68${\pm}$7.25%, 55.19${\pm}$13.19%, 57.04${\pm}$13.33%, in the marrow bone, 12.34${\pm}$14.61%, 17.56${\pm}$20.04%, 20.26${\pm}$12.83%, and in total, 30.30${\pm}$12.46%, 31.57 ${\pm}$15.15%, 34.25${\pm}$12.56% for the control, exp.1, and exp. 2 group respectively. There was no statistical difference among the groups. In all the groups significantly higher bone area were observed in the cortical bone compared to the marrow bone(p<0.05)

• 한국세라믹학회지
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• 제45권10호
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• pp.579-583
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• 2008

A porous $Al_2O_3$, scaffold coated with tricalcium phosphate(TCP) was fabricated by replica method using polyurethane(PU) foam as a fugitive material. Successive coatings of $Al_2O_3$ and hydroxyapatite(HAp) were applied via dip coating onto polyurethane foam, which has a slender and well interconnected network. A porous structure was obtained after sequentially burning out the foam and then sintering at $1500^{\circ}C$. The HAp phase was changed to TCP phase at high temperature. The scaffold showed excellent interconnected porosity with pore sizes ranging from $300{\sim}700{\mu}m$ in diameter. The inherent well interconnected structural feature of PU foam remained intact in the fabricated porous scaffold, where the PU foam material was entirely replaced by $Al_2O_3$ and TCP through a consecutive layering process. Thickness of the $Al_2O_3$ base and the TCP coating was about $7{\sim}10{\mu}m$ each. The TCP coating was homogeneously dispersed on the surface of the $Al_2O_3$ scaffold.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.195-195
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• 2016

Titanium and its alloys are widely used as implants in orthopedics, dentistry and cardiology due to their outstanding properties, such as high strength, high level of hemocompatibility and enhanced biocompatibility. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Silicon (Si) and magnesium (Mg) has a beneficial effect on bone. Si in particular has been found to be essential for normal bone and cartilage growth and development. In vitro studies have shown that Mg plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. The aim of this study is to research Si and Mg doped hydroxyapatite film formation by plasma electrolytic oxidation. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. A Si and Mg coating was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Si and Mg coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.