• 대한치과보철학회지
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• 제57권1호
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• pp.88-94
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• 2019

심미적 치료에 대한 요구가 늘어나면서 높은 강도와 심미성을 갖는 지르코니아의 요구도 증가하고 있다. 이러한 흐름에 비추어 지르코니아의 생체적 합성을 평가하는 것은 중요한 일이다. 이번 논문에서는 지르코니아의 생체적합성에 대한 in vivo 실험에 대한 문헌 연구를 진행하였다. In vivo 실험에서 연조직, 경조직에 대한 지르코니아의 생체적합성을 확인할 수 있었다. 다양한 실험동물 및 환자에서 진행된 연구의 대다수에서 지르코니아의 높은 생체적합성이 보고되었으며, 신생골 합성 및 골부착의 면에서 티타늄과 유사한 성질을 보였다. 한편, 지르코니아는 임플란트로도 활용할 수 있다. 임플란트로 활용하기 위해 HA (hydroxyapatite)를 처리하여 생체활성을 높이는 다양한 방식이 제안되고 있다. 하지만 기존의 티타늄 임플란트에 HA를 코팅하는 방식은 낮은 결합강도 및 HA의 변성으로 인한 문제점이 있었기 때문에 HA-지르코니아 composite, HA-coated 지르코니아, HA-지르코니아 functionally graded material (FGM) 또는 알루미나 개재 HA-지르코니아 등의 새로운 방식이 연구되고 있다. 이러한 방식들은 보다 높은 결합강도를 지니고 있으며, 높은 생체적합성을 보여주고 있다.

• 치위생과학회지
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• 제12권2호
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• pp.155-162
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• 2012

본 연구는 소목(Caesalpinia sappan L.)의 6가지 유기용매 분획물 중 IP-3의 항균활성을 및 부착능을 측정하고 다음과 같은 결과를 얻었다. 1. Methanol에 의해 분리된 소목의 항균 물질 수율은 총 4.8%로 나타났으며, 여러 분획물 가운데 EtOAc 분획물(IP-3)에서 3.94%로 가장 높은 수율을 보였다. 2. 소목의 EtOAc 분획물에서 최종 정제된 활성물질은 UV 288.3 nm에서 최대 흡수피크를 나타내었으며, NMR spectrum을 통해 brazilin(($C_{16}H_{14}O_5$)으로 확인되었다. 3. S. mutans에 대한 소목의 EtOAc 분획물의 항균 활성은 최소억제농도(MIC) 3.1 mg/ml에서 균의 생장을 억제하였다. 4. S. mutans 부착억제효과는 하이드록시아파타이트(HA)를 S. mutans와 24 시간 동안 함께 배양한 대조군은 균 부착률이 높게 관찰되었으나, 소목의 EtOAc 분획물을 처리한 군에서는 HA에 S. mutans의 부착이 매우 적게 나타났다. 이상의 결과를 통해, 소목에서 추출된 EtOAc 분획에 존재하는 brazilin이 구강 내 우식원성세균에 강한 항균력을 가지고 있는 것으로 판단되며, 특히 S. mutans의 부착 억제능이 확인되어 우식원성 균주에 대한 생약치료제로 활용이 가능할 것으로 사료된다.

• 치위생과학회지
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• 제16권1호
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• pp.70-76
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• 2016

이번 연구의 목적은 하이드록시아파타이트를 이용하여 블라스팅 처리한 뒤 양극산화 방법을 이용하여 하이드록시아파타이트와 이산화티탄이 복합된 표면을 만들고, 이에 대해 세포부착양상을 관찰하고 ALP 활성도와 칼슘 침착량을 측정함으로써 세포 분화능을 평가하여 표면의 생체적합성을 평가하는 데 있다. 이를 위해 실험을 진행한 결과 다음과 같은 결과를 얻었다. 접촉각 분석 결과, 복합처리된 HA+100과 HA+MAO 150은 유의하게 낮은 접촉각을 나타내었다(p<0.05). 세포부착 관찰 결과 연마 처리한 SM 시편에서는 납작한 모양으로 세포가 붙어있는 모습을 관찰할 수 있었으나, 표면 처리된 실험군에서는 세포의 모양이 시편을 따라 좀 더 길게 뻗어 부착된 모습을 관찰할 수 있었다. ALP 활성도 측정 결과 HA+MAO 150과 HA+MAO 200은 1, 2, 3주 모든 기간에서 가장 높은 ALP 활성도를 나타내었다(p>0.05). 칼슘양 측정 결과 HA+MAO 150 과 HA+MAO 200은 1, 2, 3주 모든 기간에서 가장 많은 칼슘양을 나타내었다(p<0.05). 따라서 하이드록시아파타이트 이산화티탄이 복합 코팅된 표면은 높은 표면에너지를 가지며 우수한 세포활성도를 나타내어 치과용 임플란트 표면으로 유용하게 사용될 수 있을 것이라고 생각된다.

• 폴리머
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• 제36권3호
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• pp.357-363
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• 2012

Poly(L-lactic acid)(PLLA) 고분자 필름 및 지지체의 세포 친화성을 향상시키기 위하여 산소 플라즈마 처리후 카복실기를 함유한 아크릴산(AA)을 $in$ $situ$ 그래프트시켰다. Stimulated body fluid(SBF) 용액에 15일간 담지시킨 후 hydroxyapatite(HA)를 형성시킨 시료와 phosphate-buffered saline(PBS), fetal bovine serum(FBS), 식염수 및 세포 배양용 배지에 담지시킨 다음 PLLA 시료 표면의 접촉각을 비교해 본 결과, HA 표면이 가장 낮은 접촉각을 나타내었다. 또한 연골세포와 조골세포는 HA 표면 위에서 높은 점착과 성장을 보였으며 연골세포가 HA에 많은 영향을 받는 것으로 확인되었다. 조골세포의 경우 HA 표면 이외에도 FBS나 세포 배양배지에 담지된 표면에서도 높은 세포 증식을 보였다. 더욱이 필름형태보다는 3차원 입체 구조의 다공성 지지체에서 연골세포와 조골세포의 점착과 세포 증식이 향상됨도 확인할 수 있었다. 이러한 표면개질된 PLLA는 조직공학적으로 연골이나 뼈 재생을 위한 유-무기 하이브리드 지지체로 응용될 수 있을 것으로 기대된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.51.2-51.2
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• 2011

A novel electrospun nanofiber membrane was fabricated using combined poly (vinylphosphonic acid) (PVPA) and polyvinyl alcohol (PVA) intended for bone tissue engineering applications. PVPA is a proton-conducting polymer used as primer for bone implants and dental cements to prevent corrosion and brush abrasion. The phosphonate groups of PVPA have the ability to crosslink and attach itself to the hydroxyapatite surface facilitating faster integration of the biomaterial to the bone matrix. PVA was combined with PVPA to provide hydrophilicity, biocompatibility and improve its spinnability. To improve its mechanical strength, PVPA/PVA and neat PVA mixtures were combined to produce a multilayer scaffold. The physical and chemical properties of the of the fabricated matrix was investigated by SEM and TEM morphological analyses, tensile strength test, XRD, FT-IR spectra, swelling behavior and biodegradation rates, porosity and contact angle measurements. Biocompatibility was also examined in vitro by cytotoxicity and cell proliferation studies with MTT assay and cell adhesion behavior by SEM and confocal microscopy.

• 동의생리병리학회지
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• 제29권2호
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• pp.189-194
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• 2015

Streptococcus mutans (S. mutans) is one of the most important bacteria in the formation of dental plaque and dental caries. S. mutans adheres to an acquired pellicle formed on the tooth surface, and aggregates with many oral bacteria, and initiates plaque formation by synthesizing glucan from sucrose, which is catalyzed by glucosyltransferases. S. mutans metabolizes the dietary sugar to the organic acids. The organic acids demineralize tooth surface and result in dental caries. Galla Chinensis have been traditionally used for stopping bleeding of gingiva, removing edema and halitosis, drainage, fixing the teeth and as an antiphlogistic agent. In previous reports, antibacterial effects of Galla Chinensis have been investigated whereas anti-cariogenic effects is still not examined enough. Therefore we tested effects of ethanol extracts of Galla Chinensis on the cariogenic properties such as the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In the result, ethanol extracts of Galla Chinensis showed the inhibition of S. mutans growth and organic acids production over 0.031 mg/ml concentrations. The adhesion of S. mutans to Saliva-coated Hydroxyapatite beads S-HAs has decreased with the increase of concentration of ethanol extracts of Galla Chinensis. And it seems to have adhesion inhibitory effect in concentration of over 0.25 mg/ml. It gives us the result that Galla Chinensis have anti-caries effects. But ethanol extract of Galla Chinensis didn't have inhibitory effect on insoluble glucan synthesis. Preliminary phytochemical analysis of the ethanol extract of Galla Chinensis showed strong phenolic compounds, medium steroids & terpenoids and glycosides, and weak organic acids and peptides. These results suggest that the ethanol extracts of Galla Chinensis may have anti-cariogenic properties, which may be able to be related with strong phenolic compounds.

• 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.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.402-408
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• 2013

PURPOSE. The aim of this study was to evaluate the surface properties and in vitro bioactivity to osteoblasts of magnesium and magnesium-hydroxyapatite coated titanium. MATERIALS AND METHODS. Themagnesium (Mg) and magnesium-hydroxyapatite (Mg-HA) coatings on titanium (Ti) substrates were prepared by radio frequency (RF) and direct current (DC) magnetron sputtering.The samples were divided into non-coated smooth Ti (Ti-S group), Mg coatinggroup (Ti-Mg group), and Mg-HA coating group (Ti-MgHA group).The surface properties were evaluated using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy (AFM). Cell adhesion, cell proliferation and alkaline phosphatase (ALP) activity were evaluated using MC3T3-E1 cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed. RESULTS. Cross-sectional SEM images showed that Mg and Mg-HA depositionson titanium substrates were performed successfully. The surface roughness appeared to be similaramong the three groups. Ti-MgHA and Ti-Mg group had improved cellular responses with regard to the proliferation, alkaline phosphatase (ALP) activity, and bone-associated markers, such as bone sialoprotein (BSP) and osteocalcin (OCN) mRNA compared to those of Ti-S group. However, the differences between Ti-Mg group and Ti-MgHA group were not significant, in spite of the tendency of higher proliferation, ALP activity and BSP expression in Ti-MgHA group. CONCLUSION. Mg and Mg-HAcoatings could stimulate the differentiation into osteoblastic MC3T3-E1 cells, potentially contributing to rapid osseointegration.

• 대한구강악안면임플란트학회지
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• 제18권2호
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• pp.120-138
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• 2014

Purpose: The purpose of this study was to review the outcomes of a series of studies on tissue regeneration conducted in multiple institutions including the Department of Periodontology, College of Dentistry, Yonsei University. Materials and Methods: Studies were performed divided into the following three subjects; 1) Development of three-dimensional nano-hydroxyapatite (n-HA) scaffold for facilitating drug release and cell adhesion. 2) Synergistic effects of bone marrow-derived mesenchymal stem cells (BMMSC) application simultaneously with platelet-rich plasma (PRP) on HA scaffolds. 3) The efficacy of silk scaffolds coated with n-HA. Also, all results were analyzed by subjects. Results: Hollow hydroxyapatite spherical granules were found to be a useful tool for the drug release and avidin-biotin binding system for cell attachment. Also, BMMSC simultaneously with PRP applied in an animal bone defect model was seen to be more synergistic than in the control group. But, the efficacy of periodontal ligament cells and dental pulp cells with silk scaffolds could not be confirmed in the initial phase of bone healing. Conclusion: The ideal combination of three elements of tissue engineering-scaffolds, cells and signaling molecules could be substantiated due to further investigations with the potentials and limitations of the suggested list of studies.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. 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. Manganese(Mn) 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. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. 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. Mn coatings 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 Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.