• 대한의용생체공학회:의공학회지
• /
• 제11권1호
• /
• pp.5-12
• /
• 1990

Calcium phosphate ceramics have been applied intensively to orthopaedic and dental implants by virtue of their osteoconductive nature. In an attempt to enhance the bone implant intergrity and Eta utility, these ceramics are deposited onto the porous surface of metallic implants. The coating procedure and the ensuing phase transformations of the ceramic alter the mechanical properties and surface chemistry of the ceramic layers as well as those of the substrate. These structural and compositional differences are directly related to the interaction mechanisms at the surface-active ceramicbone interface. Material and processing induced influences on dissolution, electrokinetic behavior, ceramic-metallic substrate interface and boRe growth enhancement are presented.

• 대한영상의학회지
• /
• 제83권4호
• /
• pp.931-937
• /
• 2022

금속성 임플란트 삽입과 관련된 만성 염증 상태는 미만성 거대 B세포 림프종 발생의 위험 요소이다. 금속 이온은 림프종의 발병에 중요한 역할을 하는 것으로 알려져 있다. 저자들은 15개월 동안 근위 경골에 금속성 임플란트가 삽입된 환자에서 발생한 드문 미만성 거대 B세포 림프종 증례를 보고하고자 한다. 초음파 및 자기공명영상을 촬영하였으며 현저한 골 파괴 없이 불균형적으로 큰 골외 연조직 종괴와 골수 침범이 관찰되었다. 금속성 임플란트 삽입과 관련된 여러 합병증들이 있으며 오진하면 잘못된 치료로 이어질 수 있다. 따라서 금속성 임플란트로 인한 만성 염증 상태와 연관된 림프종과 임플란트 주위에 발생할 수 있는 다른 양성 병변 및 악성 연조직 종괴를 감별하는 것은 어렵지만 매우 중요하다.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
• /
• pp.248-249
• /
• 2006

Direct Metal Laser Sintering (DMLS) has been utilized for prototype manufacturing of functional metal components for years now. During this period the surface quality, mechanical properties, detail resolution and easiness of the process have been improved to the level suitable for direct production of complex metallic components for various applications. The paper will present the latest DMLS technology utilizing EOSINT M270 laser sintering machine and EOSTYLE support generation software for direct and rapid production of complex shaped metallic components for various purposes. The focus of the presentation will be in rapid manufacturing of customized biomedical implants and surgical devices of the latest stainless steel, titanium and cobalt-chromium-molybdenum alloys. In addition to biomedical applications, other application areas where complex metallic parts with stringent requirements are being needed will be presented.

• Archives of Plastic Surgery
• /
• 제38권4호
• /
• pp.458-464
• /
• 2011

Purpose: Metacarpal fractures are common hand injury that may require operative intervention to ensure adequate reduction and stabilization. Traditionally, titanium miniplate was used for rigid fixation of bone fractures. However, the use of permanent plate lends itself to multiple complications such as infection, exposure of the hardware, tendon adhesions, tendon rupture, prolonged pain, bony atrophy and osteoporosis (stress shielding), metal sensitization, and palpation under the skin. This study evaluated the usefulness and stability of biodegradable plates and screws for treatment of metacarpal bone fractures. Methods: There was 17 patients who had surgery for metacarpal bone fracture from April 2007 to June 2010. All patients had open reduction and internal fixation. We used absorbable plates and screws (Inion CPS$^{(R)}$) for internal fixation. Postoperative results were assessed with x-ray. Stability of plates and screws, healing process and its complications were observed by clinical and radiographic assessment. Results: All patients were successfully reduced of bone fracture, and fixations with absorbable plates and screws were stable. The mean follow up period was 7.1 months. 2 patients complained postoperative pain, but they were relieved with analgesics. All patients experienced transient stiffness, but they were relieved with active assistive range of motion after removal of splint. No patients suffered complications which could be occurred by using metallic plate. Conclusion: There was no critical complications such as re-fracture or nonunion among patients. No patients suffered side effects related with metallic implants. Biodegradable implants can offer clinically stable and attractive alternative to metallic implants to stabilize metacarpal bone fractures in the hand.

• 한국분말재료학회지
• /
• 제8권1호
• /
• pp.1-12
• /
• 2001

• 한국재료학회지
• /
• 제31권12호
• /
• pp.690-696
• /
• 2021

The purpose of this study is to develop a zirconium-based alloy with low modulus and magnetic susceptibility to prevent the stress-shielding effect and the generation of artifacts. Zr-7Cu-xSn (x = 1, 5, 10, 15 mass%) alloys are prepared by an arc melting process. Microstructure characterization is performed by microscopy and X-ray diffraction. Mechanical properties are evaluated using micro Vickers hardness and compression test. The magnetic susceptibility is evaluated using a SQUID-VSM. The average magnetic susceptibility value of the Zr-7Cu-xSn alloy is 1.176 × 10^-8 cm³g^-1. Corrosion tests of zirconium-based alloys are conducted through polarization test. The average Icorr value of the Zr-7Cu-xSn alloy is 0.1912 ㎂/cm². The elastic modulus value of 14 ~ 18 GPa of the zirconium-based alloy is very similar to the elastic modulus value of 15 ~ 30 GPa of the human bone. Consequently, the Sn added zirconium alloy, Zr-7Cu-xSn, is very interesting and attractive as a biomaterial that reduces the stress-shielding effect caused by differences of elastic modulus between human bone and metallic implants. In addition, this material has the potential to be used in metallic dental implants to effectively eliminate artifacts in MRI images due to low magnetic susceptibility.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제28권2호
• /
• pp.127-135
• /
• 2006

Objectives: The extent of bone formation that occurs at the interface of metallic implants and bone is determined by the number and activity of osteoblastic cells. Stress proteins may be contributing determinants of cell viability in altered environments. Hsp27 is a small Mr hsp which is known as a molecular chaperone. Methods: To better understand how heat shock protein 27 contributes to endosseous implant - associated metal ions affects on osteoblastic cell viability, the effect of chromium and titanium ions were compared to effects of cadmium ions in the ROS17/2.8 osteoblastic cell line. Results: ROS17/2.8 osteoblastic cell line demonstrated ion - specific reductions in growth; reductions were significantly greater for cadmium than for chromium or titanium. Chromium impaired growth of cultures without altering cell viability measured using the MTT assay. A stable transformed cell line expressing additional hsp27(clone "A7") was resistant to the toxic effects of titanium and partially protected from cadmium toxicity. Conclusions: A role for hsp27 in protection of osteoblastic cells from metal ion toxicity is supported by the chromium - induced elevations in hsp27 abundance and the behavior of the A7 cell line in response to metal ions in culture. Similar biochemical responses to altered cellular environments may contribute to the fate of tissues adjacent to select metallic implants.

• The Journal of Advanced Prosthodontics
• /
• 제12권2호
• /
• pp.67-74
• /
• 2020

PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

• 대한두경부종양학회지
• /
• 제27권2호
• /
• pp.218-221
• /
• 2011

The anterior approach to the cervical spine surgery is associated with possible complications such as dysphagia, hoarseness and granuloma formation etc. Because of orthopedic metallic plates, the increasing or focal uptake pattern may be demonstrated in $^{18}F$-FDG PET/CT scan. A 67-year-old-man came to our department, complained of dysphagia during the 4 months. He underwent cervical spine surgery three years ago. The CT and MRI findings mimicked typical posterior pharyngeal wall cancer with cervical metastasis. Furthermore, the SUV in $^{18}F$-FDG PET/CT was 10.3. But he was finally diagnosed as a granuloma resulting from the metallic cervical implants. The clinical correlation and medical history should be taken into account to avoid false-positive findings in PET/CT and to avoid many erroneous diagnostic pathways.

• 대한치과교정학회지
• /
• 제9권1호
• /
• pp.23-35
• /
• 1979

The present study has the purpose of investigating various growth and developmental aspects of rabbit snout with the aid of metallic implantation and of improving on the indirect method of growth and developmental studies of its skull. Sixty-eight growing albino rabbits were used. A head holder, film holder, cephalometer, metallic implanting device and implant materials were designed and constructed by the author. Eight metallic pins were implanted with a metallic implanting device in the rabbit snout under general anesthesia. Two metallic pins were implanted on each side of the interfrontal suture and another two were put on each side of the internasal suture near the frontonasal suture. Serial cephalograms were taken with a two-week interval, using the head holder, film holder and cephalometer. Eight items of linear measurement were obtained from the film. On the base of the results of the study, the following conclusions are obtained: 1. The metallic implant method is better than the other indirect methods for growth and developmental studies of the rabbit skull. 2. Most of the vertical growth of the rabbit snout is due to sutural growth at the frontonasal suture and the horizontal growth is at the interfrontal and the internasal suture. 3. The vertical growth of the rabbit snout is greater than the horizontal growth. 4. The horizontal growth of the rabbit snout is greater at the nasal bone than at the frontal bone. 5. The amount of vertical growth of the rabbit snout is almost same at inner and outer side of the interfrontal and internasal suture line, 6. Growth rate of the sutural growth of the rabbit snout tends to decrease by the growth of the rabbit. 7. Implant materials do not disturb growth and development of the rabbit snout, except a slight trauma effect during the first week of metallic implantation.