• Corrosion Science and Technology
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• 제23권1호
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• pp.41-53
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• 2024

Titanium alloy is gaining attention in the medical industry due to its excellent biocompatibility and osteoconductivity. However, the natural oxide film on the titanium surface is insoluble, resulting in inadequate bone adhesion. Therefore, it is necessary to optimize the contact between biological tissues and implant surfaces, and alter the chemical composition and morphological characteristics of the implant surface. In this study, the anodization method was applied to titanium surface treatment to form a uniform and robust oxide film. Subsequently, a chemical process, pore-widening, was employed to change the morphological characteristics of the oxide film. The concentration of the pore-widening solution was varied at 2, 4, 6, and 8 wt% and the process time was set at 30 and 60 minutes. As the concentration of the pore-widening solution increased the pore diameter of the oxide film increased. Notably, at 6 wt% for 60 minutes, the oxide film exhibited a coexistence of pillars and pores. Based on this, it was determined that surface roughness increased with higher concentration and longer process time. Additionally, the presence of pillars and pores structures maximized hydrophilicity. This study provides insights into enhancing the surface properties of titanium for improved performance in medical implants.

• 폴리머
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• 제32권4호
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• pp.359-365
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• 2008

전기방사법에 의해 미생물 유래의 나노섬유 부직포를 제조하였고, 전자선조사에 의해 나노섬유상에 poly(N-isopropylacrylamide)(PIPAAm)을 그래프트함으로써 온도응답성 나노섬유표면을 제조하였다. 얻어진 나노섬유는 랜덤하게 배열되었으며 평균직경이 400 nm이었다. ATR-FTIR 및 ESCA 분석에 의해서 PIPAAm이 나노섬유 표면에 성공적으로 그래프트되었음을 확인하였다. PIPAAm을 그래프트 하지 않은 표면에서는 물접촉각의 변화가 없었으나, PIPAAm이 그래프트된 나노섬유 표면에서는 온도가 $37^{\circ}C$에서 $20^{\circ}C$로 바뀜에 따라 물접촉각이 감소하였다. 이러한 결과는 PIPAAm이 그래프트된 표면에서 높은 온도에서는 소수성의 특성을 가지다가, 낮은 온도에서는 PIPAAm 사슬이 수화되면서 친수성으로 바뀌었기 때문이다. 제조한 온도응답성 나노섬유는 조직적합성이 우수하였으며, 저온처리에 의해 배양세포가 원활히 탈착 회수됨을 알 수 있었다.

• 한국안광학회지
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• 제7권2호
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• pp.1-11
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• 2002

눈물 층을 사이에 두고 각막 위에 부착되어 있는 콘택트 렌즈(하드렌즈)에는 모세관 현상에 따른 장력이 렌즈 가장 자리에 균일하게 방사형으로 작용한다. 이러한 장력은 렌즈가 각막에 부착되는 힘의 근원이 된다. 렌즈착용 시 자체 무게에 의한 렌즈의 회전과 렌즈가 평형상태에 도달 한 후 각막에 부착되는 힘을 계산할 수 있는 방정식과 이의 수치 계산 컴퓨터 프로그램을 수립하였으며 이 컴퓨터 모델을 사용하여 렌즈 구경, 렌즈 B.C, 눈물의 점성, 눈물 층의 두께 등의 변수가 렌즈의 평형 위치 및 부착력에 미치는 영향을 모사(simulation)하였다. 일정 각막 B.C에서 렌즈 B.C 증가에 따라 눈물 충의 간격은 급격히 증가하는데 비해 렌즈의 직경 증가는 완만한 간격 증가를 수반한다. 렌즈의 B.C가 증가할수록, 즉 렌즈의 곡률이 완만할수록, 렌즈가 각막에 fitting되는 부착력은 급격하게 감소하며 직경 감소는 완만한 부착력 감소를 초래한다. 렌즈가 각막에 부착되는 순간 렌즈의 무게로 인하여 아래 방향으로의 회전 모멘트가 발생하게 되며 이와 동시에 렌즈 위 부분 눈물 층의 간격이 아래 부분보다 좁아지게 되어 위 방향으로 알짜 힘이 작용하게 되며 이에 따른 역방향 모멘트는 중력에 의한 모멘트를 상쇄하게 되어 렌즈는 일정 위치에서 평형 상태에 도달하게 된다. 렌즈 착용에 수반되는 초기 회전각 또는 회전 변위는 렌즈의 B.C가 증가할수록 급격히 증가하는데 비해 렌즈 구경 증가는 변위 증가율이 완만하다.

• 대한치과보철학회지
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• 제46권3호
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• pp.307-319
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• 2008

STATEMENT OF PROBLEM: It is known that an anodic oxidation technique, one of the methods for the implant surface treatment, remarkably increased surface area, enhanced wettability and accelerated the initial bone healing. Purpose: This study was performed to evaluate the wettability of anodized titanium surface which has a nanotubular structure, to assess osseointegration after the placement of implant with nano-size tubes on tibia of rats and to analyze quantitatively transferable rhBMP-2 on each surface. MATERIAL AND METHOD: Four different kinds of surface-treated titanium discs (polished (machined surface) group, micro (blasting surface) group, nano (anodizedmachined surface) group, and nano-micro (anodized-blasting surface) group) were fabricated (n=10). Three different media were chosen to measure the surface contact angles; distilled water, plasma and rhBMP-2 solution. After a single drop (0.025 $m{\ell}$) of solution, the picture was taken with the image camera, and contact angle was measured by using image analysis system. For the test of osseointegration, 2 kinds of anodized surface (anodized-machined surface, anodized-blasting surface) implants having 2.0 mm in diameter and 5.0 mm in length inserted into the tibia of Wistar rats. After 3 weeks, tibia were harvested and the specimens were stained with hematoxylin and eosin for histological analysis. To test the possibility of drug delivery, after soaking sample groups in the concentration of 250 ng/$m{\ell}$l of rhBMP-2 for 48 hours, the excess solution of rhBMP-2 were removed. After that, they were lyophilized for 24 hours, and then the rhBMP-2 on the surface of titanium was resolved for 72 hours in PBS. All the extracted solution was analyzed by ELISA. One-way analysis of variance (ANOVA) was performed on the data. RESULTS: The wettability is improved by anodic oxidation. The best wettability was shown on the nano-micro group, and it was followed by nano group, micro group, and polished group. In the histological findings, all implants showed good healing and the new bone formation were observed along the implant surface. After 3 days, nano-micro group delivered the most amount of rhBMP-2, followed by nano group, micro group, and polished group. CONCLUSION: It indicated that anodic oxidation on blasting surface produce functionally graded nano-micro porous structure and enhance hydrophilicity of the surface and osseointegration. The findings suggest that the nano-micro porous structure could be a useful carrier of osteogenic molecules like rhBMP-2.

• 대한치과보철학회지
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• 제47권1호
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• pp.12-20
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• 2009

연구목적: 임플란트가 식립되어질 때 매식체는 조직액과 접촉하게 된다. 임플란트의 조직액 흡착은 표면처리에 따라 다양하게 나타난다. 이 때 임플란트 시편의 표면 거칠기와 젖음성과의 상관관계를 분석하고자 하였다. 연구재료 및 방법: 표면 거칠기와 젖음성의 상관관계를 측정하기 위해 네 종류의 임플란트 시편을 각각 5종류 만들었다. 각각의 그룹은 그룹 A: Machined Surface, 그룹 B: Anodized surface, 그룹 C: RBM (HA blasting) surface, 그룹 D: CMP (calcium methaphosphate) coating surface이다. 연구결과: 1. 표면의 거칠기는 RBM, CMP, Anodized, Machined 그룹 순서로 거칠었다. RBM과 CMP는 통계적으로 유의차가 없었다 (P<.05). 2. 젖음성은 Anodized, RBM, CMP, Machined 그룹 순서로 높았다. CMP와 Machined는 통계적으로 유의차가 없었다 (P<.05). 3. 표면 거칠기와 젖음성과의 상관관계는 없었다.

• 비파괴검사학회지
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• 제33권4호
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• pp.368-375
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• 2013

소구경 배관 용접부 손상은 원자력발전소에서 빈번하게 발생되고 있는 문제이며, 이러한 손상은 보수를 위한 불시정지를 야기하고 결과적으로 발전소에 경제적인 손실을 초래한다. 따라서 소켓용접부의 제작결함 검출과 초기 성장 결함의 검출은 매우 중요하다고 할 수 있다. 지금까지 해당부위에 대한 검사는 ASME Code Section XI 요건에 의하여 표면검사를 적용하여 왔으나 강화검사로 체적검사기법인 초음파검사를 병행하여 수행하고 있다. 그러나 가동중에 발생되는 피로균열을 검출하기 위하여 적용되고 있는 일반 수동 초음파검사는 소켓용접부의 접근성과 초음파 탐촉자의 접촉 문제 등으로 인하여 검사 결과의 신뢰성에 문제가 있어 왔다. 본 연구에서는 위상배열 초음파검사 기술을 적용하여 소구경 배관 소켓용접부의 검사 신뢰성과 속도를 향상하고자 하였다. 이를 위하여 소구경 배관 소켓용접부 검사를 위한 3.5 MHz 위상배열 초음파 탐촉자를 제작하고 탐촉자의 접촉 조건과 일정한 신호 품질을 유지하기 위하여 수동 엔코더 스캐너를 개발하였다. 또한 검사 시스템을 구성하고 현장 검사를 위한 절차서도 개발하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권6호
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• pp.514-523
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• 2006

The purpose of the present study was to evaluate the effects of several implant surface treatments to the bone formation, by placing Machined implants, 75${\mu}m$ Calcium phosphate-blasted implants and $Al_2O_3$-blasted and acid-etched implants in rabbit tibia through histomorphometric study. Two animals of each group were sacrificed at 2, 4, 8 weeks. The specimens containing the implants were dehydrated and embedded into hard methylmethacrylate plastic. Thereafter, the sections were ground to 50${\mu}m$. The specimens were stained with Villanueva bone stain for a light microscopic study. The results were as follows; 1. When the surface roughness of three different implants was measured by Surfcorder, the Ra of the Machined group, the RBM group and the SLA group was 0.16${\mu}m$, 0.44${\mu}m$, and 1.08${\mu}m$. 2. When examining the surfaces of the implants in the scanning microscope, Machined implant has the smooth surface with a few scratches, RBM implant has the rough surface with curled ridges and valleys, and SLA implant has the rough surface structures such as sharp protruding parts and micropits measuring 1-2${\mu}m$ in diameter. 3. After 2 weeks of implantation, the percentage of bone-to-implant contact of the Machined group, the RBM group and the SLA group was 26.86%, 35.40% and 45.99%. However, its differences between each group decreased during the healing periods. 4. After 2 weeks of implantation, the percentage of bone area inside the threads of the Machined group, the RBM group and the SLA group were 21.55%, 30.43% and 41.18%. However, its difference of bone area between machined group and surface treatment groups was maintained but the difference within the surface treatment groups decreased during the healing periods. In summary, the amount of bone formation in RBM and SLA group was greater than Machined group in early healing stage. These results suggest that RBM and SLA implants can reduce the healing period for osseointegration and may be suitable for early function.

• 한국산학기술학회논문지
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• 제14권6호
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• pp.2839-2843
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• 2013

본 연구에서는 각막굴절력에 따른 누액층 파괴시간(TBUT)의 연관성을 분석하여 콘택트렌즈의 선택 및 착용을 위한 참고자료로 활용하고자 한다. 각막손상 및 안질환이 없는 만 21세부터 27세 이하(평균 $22.87{\pm}1.48$세) 대학생들의 각막곡률반경을 각막곡률계로 측정하였다. 각막굴절력은 곡률반경을 이용하여 계산하였고 TBUT는 각막곡률계의 마이어(mire) 상이 처음으로 왜곡되는 시간으로 측정하였다. 각막굴절력과 TBUT의 관계에서 우안의 경우, 'y=37.921-0.610x'의 관계를 가지며 각막굴절력이 클수록 누액층이 파괴되는 시간이 단축되는 음의 연관성을 나타냈다(r=-0.462, p=0.010). 좌안은 'y=41.894-0.695x'의 관계로서 음의 연관성(r=-0.509, p=0.004)으로 측정되어 좌 우안 모두 각막근시도가 높으면 TBUT는 짧아지는 음의 상관관계가 있는 것으로 분석되었다. 이 결과는 피검자의 각막곡률반경 측정으로 콘택트렌즈 착용여부를 결정하는데 필요한 TBUT의 기본적인 예측이 가능하다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권6호
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• pp.397-406
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• 2003

The purpose of this study was to observe the titanium implant osseointegration in the osteoporosis-induced animal model. Seventy rats, 11 weeks of age, were divided into two groups : an ovariectomized group and a control group. Titanium screw implants(diameter, 2.0mm; length, 3.5mm) were placed into left tibias of 70 rats, 35 in the control group and 35 in the experimental group. The rats were sacrificed at different time interval (1, 2, 3, 4, 6, 8, and 12 weeks after implantation) for histopathologic observation, histomorphometric analysis and immunohistochemistry with fibronectin and CD34 antibody. The results obtained from this study were as follows: 1. Histopathologically findings, newly formed bone was seen at 3 weeks and became lamellar bone at 8 weeks, and mature trabecullar bone was seen at 12 weeks control group. In experimental group, thickness of regenerated bone increased till 8 weeks gradually and mature trabecullar bone was seen at 12 weeks. 2. By histomorphometric analysis, marrow bone density and contact ratio of marrow bone to implant decreased significantly from 8 to 12 weeks in experimental group compared to control group and also total bone to implant contact ratio decreased significantly from 8 to 12 weeks in experimental group. 3. Fibronectin immunoreactivity was strong at 3 weeks control group and reduced after 8weeks gradually. But it was continuously strong from 3 to 8 weeks in experimental group. 4. CD34 immunoreactivity was very strong in the newly formed osteoblasts from 3 to 8 weeks control group. But it reacted minimally later. While in experimental group, it reacted continuously strong from 3 to 12 weeks. The results of this study suggest that osteoporosis is not an absolute contraindication to dental implantation if sufficient period suggested after fixture installation till second stage surgery.

• 대한치과보철학회지
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• 제43권1호
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• pp.78-94
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• 2005

Purpose. The purpose of this study was to compare the effects of various surface treatments by measuring resonance frequency and histomorphometric analyses. Material and methods. In 5 adult dogs, the mandibular premolar were extracted. Six months later, 30 screw titanium implants (Dentium Co., Seoul, Korea) 6mm in length and 3.4mm in diameter, were placed in the mandibles of 5 dogs. Implants were divided into five groups following to surface treatment methods ; Group 1 is machined controls, Group 2 is sandblasted with large grit and acid-etched (SLA), Group 3 is anodized (Autoelectric Co., Korea, 660Hz, Duty10), Group 4 is hydroxyapatite(HA) coated by ion beam assisted deposition(E-beam), Group 5 is hydroxyapatite(HA) coated with Sol-gel coating process. Resonance frequency was measured implant placement immediately, and 3, 6 weeks and 10 weeks of healing perods. With the animal subject's sacrifice 10 weeks after implantation, implants were removed on bloc and histologic and computer-based histomorphometric analyses were performed. Histomorphometric analysis involved quantification of the entire bone to metal contact around the implants. Statistical analyses were performed using the SPSS for Windows (ver. 9.0 SPSS Inc.) Statistical differences were considered significant at P<0.05. Results. The results were as follows : 1) In five groups, mean value of resonance frequency analysis(RFA) were highest in group 5 (Sol-gel implant) at implantation and those of group 4 (E-beam)was highest at 10 weeks . but there was no correlation between surface treatments and RFA. 2) In all surface treatment groups, the RFA values of implants decreased until 3 weeks and increased to 10 weeks. 3) The percentage of direct bone-to-implant contact (BIC) had statistical significance between five groups in cancellous bone, (P<0.05) the percentage of bone density inside the thread had no statistical significance between five groups. (P>0.05) 4) There was a significant difference between cortical bone and cancellous bone in BIC. (P<0.05) and bone density. (P<0.05) 5) There was a correlation between the RFA value of implants at 10 weeks and BIC in cancellous bone, and between the RFA value of implants at 10 weeks and bone density in cortical bone. (P<0.05). Conclusions. These results indicate that surface treatment does not affect the implant stability in case of good bone quality.