• 대한치과보철학회지
• /
• 제52권2호
• /
• pp.105-112
• /
• 2014

연구 목적: 이 연구의 목적은 임플란트 식립 초기 수회의 의원성 동요가 최종 골결합에 미치는 영향을 확인하는 것이다. 연구 재료 및 방법: 순수한 티타늄(Grade IV) 으로 직경 3.75 mm, 길이 8 mm의 실험용 임플란트를 제작한 후, 하방 4 mm에 RBM 표면처리($MegaGen^{(R)}$: Ca-P)를 하였다. 임플란트의 하부만 골에 식립되었으며 비침하시켰다. 수술은 3.5 kg이상의 토끼의 좌우 경골의 단층 치밀골에 각각 2개씩 130개를 통상적인 방법으로 식립하였다(Female, New Zealand White). 비틀림 제거 간격에 따라, 다음과 같은 13개의 군으로 나누었다; Group I (1일), Group II (1일 + 2일), Group III (1일 + 2일 + 3일), Group IV (1일 + 2일 + 3일 + 4일), Group V (2일), Group VI (2일 + 4일), Group VII (2일 + 4일 + 6일), Group VIII (2일 + 4일 + 6일 + 8일), Group IX (4일), Group X (4일 + 7일), Group XI (4일 + 7일 + 10일), Group XII (4일 + 7일 + 10일 + 14일), 그리고 대조군. 대조군은 식립 후 8주의 치유기간을 준 후 최종 비틀림 제거력을 측정하였다(Mark-10, USA). 실험군은 각각의 조건에 맞추어 1회에서 4회에 걸쳐 비틀림 제거력을 측정하였다. 비틀림 제거력을 측정한 이후에 대체적으로 임플란트를 측정 전의 위치로 재위치시켰다. 모든 실험군에서 임플란트 식립 후 8주간의 치유기간을 준 다음 최종 비틀림 제거력을 측정하여 대조군, 각 실험군의 1, 2, 3, 4번째 비틀림 제거력과 비교하였다. 결과: 실험군 간에 최종 비틀림 제거력을 비교한 결과에서, XII군을 제외한 실험군의 비틀림 제거력은 대조군과 유의할만한 차이를 보이지는 않았다. 그리고 실험 I군과 II군의 값은 VI, VIII, X, XI, XII군의 값보다 유의하게 높게 나타났다. 그리고 III, IV, V군은 XI, XII군의 값보다 유의하게 높게 나타났다. 각 실험군간 비틀림 제거력 비교에서, 최종 비틀림 제거력은 VIII, X, XI, XII군을 제외한 모든 군에서 높게 나타났다. 결론: 충분한 치유기간이 주어진다면, 토끼에게 임플란트 식립 후 매우 이른 초기에 지대주에 가해지는 약간의 동요는 임플란트 골결합에 영향을 미치지 않았다.

• Fibers and Polymers
• /
• 제4권2호
• /
• pp.89-96
• /
• 2003

A vertebral cage is a hollow medical device which is used in spine forgery. By implanting the cage into the spine column, it is possible to restore disc and relieve pressure on the nerve roots. Most cages have been made of titanium alloys but they detract the biocompatibility. Currently PEEK (polyether ether ketone) if applied to various implants because it has good properties like heat resistance, chemical resistance, strength, and especially biocompatibility. A new shape of vertebral cage is designed and injection molding of PEEK is considered for production. Before injection molding of the cage, it is needed to evaluate process conditions and properties of the final product. Variables affecting the shrinkage of the cage are considered, e.g., injection time, packing pressure, mold temperature, and melt temperature. By using the numerical simula-tion program, MOLDFLOW, several cases are studied. Data files obtained by MOLDFLOW analysis are used for stress anal-ysis with ABAQUS, and shrinkage and residual stress fields are predicted. With these results, optimum process conditions are determined.

• Corrosion Science and Technology
• /
• 제8권2호
• /
• pp.89-92
• /
• 2009

Pure Ti as well as Ti-6Al-4V alloy exhibit excellent properties for dental implant applications. However, for a better biocompatibility it seems important to avoid in the composition the presence of V due to the toxic effects of V ion release. Thus Al and V free and composed of non-toxic element such as Nb, Zr alloys as biomaterials have been developed. Especially, Zr contains to same family in periodic table as Ti. The addition of Zr to Ti alloy has an excellent mechanical properties, good corrosion resistance, and biocompatibility. In this study, the electrochemical characteristics of Ti-Zr alloys for biomaterials have been investigated using by electrochemical methods. Methods: Ti-Zr(10, 20, 30 and 40 wt%) alloys were prepared by arc melting and homogenized for 24 hr at $1000^{\circ}C$ in argon atmosphere. Phase constitutions and microstructure of the specimens were characterized by XRD, OM and SEM. The corrosion properties of the specimens were examined through potentiodynamic test (potential range of -1500 ~ 2000 mV), potentiostatic test (const. potential of 300 mV) in artificial saliva solution by potentiostat (EG&G Co, PARSTAT 2273. USA).

• 한국재료학회지
• /
• 제14권3호
• /
• pp.211-217
• /
• 2004

The oxidation behaviors of Ti-10Ta-10Nb alloy and Ti-6Al-4V alloy were studied in dry air atmosphere. Specimens were melted in consumable vacuum arc furnace and homogenized at $1050^{\circ}C$ for 24 h. Hot rolling was performed at $1000^{\circ}C$. Specimens of the alloys were oxidized as the temperature range $400~650^{\circ}C$ for 30 min. The oxidation behavior of the alloys was analysed by optical microscope, SEM/EDX, XRD, XPS and TGA. Immersion test was performed in 1% Lactic acid. In the microscope observation, oxide layer of Ti-10Ta-10Nb alloy was denser and thinner than Ti-6Al-4V's. The weight gains during the oxidation rapidly increased at the temperature above $600^{\circ}C$ in Ti-6Al-4V's alloy and$ 700^{\circ}C$ in Ti-10Ta-10Nb alloy. According to XRD results, oxide layers were composed of mostly $TiO_2$(rutile) phase. It was analysed that the passive film of the Ti alloys consisted of $TiO_2$ through X-ray photoelectron spectroscopy(XPS) analysis.

• 대한치과기공학회지
• /
• 제23권2호
• /
• pp.223-230
• /
• 2002

Pure titanium and Ti6Al4V alloy have been mainly used as implant materials but the cytotoxicity of V, neurotoxicity of Al resulting in Alzheimer disease had been reported. This paper was described the influence of composition of Ti-Nb alloys with 3 wt%Nb, 20 wt%Nb on the microstructure and corrosion resistance. Specimens of Ti alloys were melted in vacuum arc furnace and homogenized at $1000^{\circ}C$ for 24hr. The alloys were rolled in $\beta$ and ${\alpha}+{\beta}$ regions. The corrosion resistance of Ti alloys were evaluated by potentiodymic polarization test in 0.9% NaCl and 5% HCl solutions. The results can be summarized as follows: 1. The microstructure was transformed from $\alpha$ phase to ${\alpha}+{\beta}$ phase by adding Nb 2. The hardness of Ti-20Nb alloy was greater than Cp- Ti, Ti-3Nb alloy. 3. The corrosion resistance of Ti-20Nb alloy was better than that of Cp-Ti, Ti-3Nb alloy in 0.9%NaCl and 5%HCl solutions.

• 한국기계가공학회지
• /
• 제3권1호
• /
• pp.72-78
• /
• 2004

In this paper, mechanical behaviors of developed pedicle screw system, made of bio-mechanical materials(Ti-6Al-4V, Grade 5), ale predicted using FEM analysis. As a first step, morphologic construction of normal Korean spines and surgical operation convenience are considered to design optimum pedicle screw system. In this step, various design variables are considered as design parameters to develop optimized models. As a next step, tension and bending tests are performed to improve the structural performance of the developed system using finite element method. In this step, required Static compression and bending test specifications by ASTM F-04 25 04 01 are applied to understand the bio-mechanical behaviors of the designed spinal implant system under various load types. As the results of this research, it is possible to develop efficient pedicle screw system, having enough rigidity and fixation to stand any spinal damage under allowable stress conditions.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.517-518
• /
• 2006

In this study, a commercial fixation device, BioFlex, which was designed with shape memory alloy(SMA) for dynamic stabilization of spine was biomechanically evaluated. The finite element model of intact lumbar spine from L1 to S was developed using CT images. Also, low FE models of 2-level(L4-L5-S) and 3-level(L3-L4-L5-S) posteriori fixation using titanium(Ti) rod and BioFlex(SMA) rod. The rotations of bone segments in the intact model and four models were predicted. Although the rotations of the BioFlex fixation model were smaller than those of the intact model, they were relatively larger than those of Ti fixation. The present can be applied for not only evaluation of the stability of interbody fixator, but also development of new implant.

• Journal of Periodontal and Implant Science
• /
• 제36권3호
• /
• pp.627-637
• /
• 2006

이 연구는 rh BMP-7-immobilized substrates에 대한 백서 태자 두개관 세포의 반응을 석회화 결절 측정, 알카리 효소 분석, 역전사 중합반응 및 단백질 분석등으로 평가하여 다음과 같은 결과를 얻었다. 1. 배양 14일 째, 석회화 결절 형성율을 측정한 결과, rh BMP-7-immobilized substrates에서 대조군과 비교하여 더 많은 석회화 결절을 형성하였다. 2. 배양 7일에 염기성 인산 분해효소 활성도는 rh BMP-7-immobilized substrates에서 대조군에 비해 효소 활성도가 유의하게 높았다. 3. 역전사 중합반응의 결과에서 BSP 와 OCN 유전자 발현은 대조군보다 더 현저하였다. 4. 단백질 분석에서 rh BMP-7-immobilized substrates와 대조군 모두 Smad 1,5,8 단백질의 인산화를 활성화시키지 못했다. 이상의 결과 rh BMP-7-immobilized substrates는 백서 태자 두개관세포가 조골세포로의 분화와 석회화를 유도하며 따라서 rh BMP-7-immobilized substrates는 임프란트 주변의 골 형성에 유용하리라 사료된다.

• Journal of Periodontal and Implant Science
• /
• 제27권1호
• /
• pp.91-109
• /
• 1997

본 연구에서는 악골에 식립된 순수한 타이타늄 임프란트와 타이타늄 플라즈마 처리된 타이타 늄 임프란트 및 수산화인회석으로 피막처리된 타이타늄 임프란트의 주위 골조직을 광학현미경 과 주사전자현미경을 이용하여 비교 관찾히였다. 3 마리의 beagle dog 에서 상하악 소구치를 편측으로 발거한 후 12 주의 치유기를 거쳐 임프란트 를 식립하였으며, 임프란트 식립 후 4주, 8주 및 12주에 실험동물을 각각 희생시켜서 조직 표본을 제작하였다. 임프란트 주위의 골조직에서 염증이나 이물반응은 관찰되지 않았으며, 정상적인 악골에서와 유사한 골조직 소견이 관찰되었다 상악골 및 하악골에 식립된 모든 임프란트의 4주 표본에서, 골과 임프란트 변의 직접적인 접촉이 관찰되었다. 동일한 치유기에서는, 상악골에 식립된 임프란트의 면에 비하여 하악골에 식립된 동종의 임프란트의 변에서 더 많은 양의 골접촉이 관찰되었으며, 순수한 타이타늄 임프란트의 면에 비하여 피막처리된 타이따늄 임프란트의 변에서 더 많은 양의 골접촉이 관찰되었다.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1996년도 춘계학술대회
• /
• pp.133-136
• /
• 1996

We investigated how hydroxyapatite (HA) coating onto a porous super stainless steel (S.S.S, 22Cr-20Ni-6Mo-0.25N) affects bone ingrowth in a dog transcortical femoral model. Implants were histologically evaluated after 4 and 48 weeks of implantation, and the bone bonding strength at the bone/implant interface was examined by employing the pull-out test. The direct osseous tissue bonding onto the HA-coated S.S.S was observed, but the uncoated stainless steels had thin fibrous tissue layers. The mean interface strength of the HA-coated S.S.S was 1.5 and 2.5 times greater than those of the S.S.S and the 316L SS after one year of implantation, respectively. In preliminary studies, no toxic responce was observed from a cytotoxicity test of the S.S.S, having similar corrosion resistance to titanium. Our results suggest that early osteoconductive nature of HA coating may induce long term osteointegration for a bioinert substrate.