• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2011년도 춘계학술발표대회
• /
• pp.53.1-53.1
• /
• 2011

Bioactive glass powders were synthesized by hydrothermal chemical route by the use of ultrasonic energy irradiation. We used sodalime, calcium nitrate tetra hydrate and di ammonium hydrogen phosphate as the precursor material to synthesize $SiO_2$ rich bio-active glass materials. The $SiO_2$ content was varied in the precursor mixture to 60, 52 and 45 mole%. Dense compacts were obtained by microwave sintering at $1,100^{\circ}C$. Mechanical properties were characterized for the fabricated dense bioactive glasses and were found to be comparable with conventional CaO-$SiO_2$-$Na_2O$-$P_2O_5$ bioactive glass. Detailed biocompatibility evaluation of the glass composition was investigated by in-vitro culture of MG-63 cell and mesenchyme stem cell. Cell adhesion behavior was investigated for both of the cell by one cell morphology for 30, 60 and 90 minutes. Cell proliferation behavior was investigated by culturing both of the cells for 1, 3 and 7 days and was found to be excellent. Both SEM and confocal laser scanning microscopy were used for the investigation. Western blot analysis was performed to evaluate the bimolecular level interaction and extent and rate of specific protein expression. The ability to form biological apatite in physiological condition was observed with simulated body fluid (SBF). In-vivo bone formation behavior was investigated after implanting the materials inside rabbit femur for 1 and 3 month. The bone formation behavior was excellent in all the bioglass compositions, specially the composition with 60% $SiO_2$ content showed most promising trend.

• 대한임상검사과학회지
• /
• 제48권2호
• /
• pp.114-117
• /
• 2016

골은 일생에 걸쳐 지속적인 재형성과장을 거치면서 유지되고 이러한 기전에 대한 연구는 골다공증을 비롯한 골대사 질환의 병태생리와 치료에 있어 큰 진전을 이루고 있다. 특히 생체 내 골형성 및 재생과정을 연구하는데 있어 형광표지자를 이용하는 방법이 널리 알려져 있는데, 그 중 calcein은 칼슘 킬레이터로 골이 새롭게 형성하는 부위에 녹색을 띔으로써 유용한 마커로 사용된다. 그러나 대부분의 골형성 연구에서 실험동물의 경우 표본제작을 할 때 크기가 작고 뼈가 부숴지기 쉬워 rat이나 rabbit을 이용하였으며, mice의 femur를 cross-section해서 관찰한 연구는 거의 없는 실정이다. 그래서 본 연구에서는 어린 mice를 실험동물로 이용하였으며, 생체 내 calcein을 4주간, 8주간 투여한 후 골 형성 변화를 형광현미경으로 관찰한 결과 8주차 쥐에서 4주차보다 진하고 골 형성 간격도 넓게 관찰된 것을 확인 할 수 있었다. Mice는 빠른 시일 내에 결과를 얻을 수 있고 부작용이 적은 장점이 있어서 앞으로 knock-out mice를 이용한 생체 내 실험에 활용하기 적합하다고 생각되며, 골형성 속도 평가 등 다양한 분야에서의 골 형성과 재생연구에 있어 기초 정보를 제공할 것으로 기대한다.

• Journal of Periodontal and Implant Science
• /
• 제52권3호
• /
• pp.242-257
• /
• 2022

Purpose: This study investigated periodontal ligament (PDL) restoration in osseointegrated implants using stem cells. Methods: Commercial pure titanium and zirconium oxide (zirconia) were coated with beta-tricalcium phosphate (β-TCP) using a long-pulse Nd:YAG laser (1,064 nm). Isolated bone marrow mesenchymal cells (BMMSCs) from rabbit tibia and femur, isolated PDL stem cells (PDLSCs) from the lower right incisor, and co-cultured BMMSCs and PDLSCs were tested for periostin markers using an immunofluorescent assay. Implants with 3D-engineered tissue were implanted into the lower right central incisors after extraction from rabbits. Forty implants (Ti or zirconia) were subdivided according to the duration of implantation (healing period: 45 or 90 days). Each subgroup (20 implants) was subdivided into 4 groups (without cells, PDLSC sheets, BMMSC sheets, and co-culture cell sheets). All groups underwent histological testing involving haematoxylin and eosin staining and immunohistochemistry, stereoscopic analysis to measure the PDL width, and field emission scanning electron microscopy (FESEM). The natural lower central incisors were used as controls. Results: The BMMSCs co-cultured with PDLSCs generated a well-formed PDL tissue that exhibited positive periostin expression. Histological analysis showed that the implantation of coated (Ti and zirconia) dental implants without a cell sheet resulted in a well-osseointegrated implant at both healing intervals, which was confirmed with FESEM analysis and negative periostin expression. The mesenchymal tissue structured from PDLSCs only or co-cultured (BMMSCs and PDLSCs) could form a natural periodontal tissue with no significant difference between Ti and zirconia implants, consequently forming a biohybrid dental implant. Green fluorescence for periostin was clearly detected around the biohybrid implants after 45 and 90 days. FESEM showed the invasion of PDL-like fibres perpendicular to the cementum of the bio-hybrid implants. Conclusions: β-TCP-coated (Ti and zirconia) implants generated periodontal tissue and formed biohybrid implants when mesenchymal-tissue-layered cell sheets were isolated from PDLSCs alone or co-cultured BMMSCs and PDLSCs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제28권4호
• /
• pp.302-309
• /
• 2002

In order to improve the success rate of implants, various implant designs have been developed. Although there have been enough efforts to handle the surface of the implant with careful choice of material and mechanics so that the bone and the implant can be tightly joined together, they have still failed to play the role of periodontal ligaments of the natural teeth in the past. The role of periodontal ligaments is very important since it can improve the initial stability of implant by absorbing the impacts. The purpose of this study is, thus, to test the possibility of alleviating the impact when the surface of the implant was coated with chitosan, a natural polymer, and making sure that the coated material stayed on. Then, the condition of newly developed bone formation and the degree of inflammation in response was closely observed in the surface level. In the main experiment, Chitosan coated implant ($3.3mm{\times}7mm$) was implanted on both the right and the left side of rabbit's femur. The animals were each sacrificed on the $1^{st}$, $2^{nd}$, $3^{rd}$, $7^{th}$, $14^{th}$, $21^{st}$ and 28th day. The process was observed under an light microscope after the Toluidin Blue staining. From the experiment, it was found that the chitosan was evenly distributed on the surface of the screws, and the implant was adjoined with adjacent bone. There was a sign of inflammation on the $3^{rd}$ day, but on the $14^{th}$ day, the formation of woven bone and newly formed bones were noticed. Also, chitosan filled the gap was formed between the implant and the newly formed bone. The implant, the chitosan and the newly formed bone were forming one unit as a result. Therefore, it was found that chitosan coated implant could absorbe the impact in the initial stage of implant.

• 대한치과보철학회지
• /
• 제29권2호
• /
• pp.225-243
• /
• 1991

In recent years immediate implantation has been tried by a few clinicians. This study placed IMZ implants in the rabbit femur with and without bony defects around the implant for simulating fresh extraction site. And one group with bony defects used porous hydroxyapatite ganules(HA) to fill if and the other group left the bony defects around the implant. The purpose of this study was to compare the shear bond strength and the bony contact and formation around the implant. Fifteen rabbits were divided into three groups and placed 10 IMZ implants to each group. Implant sites were surgically prepared with IMZ drills kit and implants were placed(Control), artificial bony defect was created with Apaceram drills kit around the implant sites and implants were placed(Experimental I), bony defect was filled with porous hydroxyapatite granules(Experimental II). Thereafter, rabbits were sacrificed at 8th week and specimens were prepared and pushout tested for shear bond strength of bone-implant interface immediately. Undecalcified and decalcified specimens were prepared with Vilanueva and hematoxylin-eosin stain for light microscopic finding. The results of this study were as follows. 1. In the control group, mean shear strength of bone-implant interface was $2.614{\pm}0.680$ MPa, experimental I was $0.664{\pm}0.322$ MPa, and experimental II was $2.281{\pm}0.606$ MPa. There was significant difference between control and experimental I, between experimental I and experimental II, but did not show significant difference between control and experimental II statistically. 2. In the bony formation surrounding IMZ implant of the three groups, that of cortical bone is more advanced than cancellous bone area. 3. In the histological findings of undecalcified specimens, control and experimental II showed more than 50% of bony or osteoid formation at the bony-implant interface. 4. In the histological findings of undecalcified specimens, experimental I showed less than 50% of bony or osteoid formation at the interface, and observed partial bony defect in the coronal zone. 5. In the experimental II group, were observed direct bony contact to hydroxyapatite granules, and infiltration of a few giant cells. 6. No inflammatory responses were seen around the titanium implants and the hydroxyapatite granules.

• Journal of Yeungnam Medical Science
• /
• 제13권1호
• /
• pp.116-133
• /
• 1996

생체합금의 생체적합성을 검증하기위해, 표면처리가 되지 않은 타이타늄 봉과 표면처리를 시행한 타이타늄 봉을 실험용토끼의 대퇴골 근위부에 삽입하여 6주, 12주 및 26주후 방사선 관찰 후 광학현미경적 검사를 통한 골 반응을 비교 관찰하였다. 전 례에서 부식에 의한 반응은 관찰되지 않았으며, 신생골의 증식은 타이타늄의 삽입 후 26주까지 경도의 골증식이 관찰되었으나, 표면처리여부에는 관계가 없었다. 표면처리를 시행하지 않은 타이타늄의 삽입한 11례 중 1례의 경우 삽입 후 12주에 경도의 골괴사반응이 관찰되었으며 표면처리를 시행한 타이타늄을 삽입한 후 전 례에서 골괴사가 관찰되지 않았다. 이는 수술적 조작에 의한 것으로 사료되었다. 섬유원세포의 증식은 시기에 관계없이 전 례에서 관찰되었으며, 표면처리 여부 혹은 시간의 경과 정도와 관계가 없었다. 표면처리를 시행하지 않은 타이타늄의 삽입 후 6주에는 침윤정도 및 조직반응정도는 표면처리한 타이타늄의 삽입에 비해 통계적으로 유의하게 증가하였다. 그러나, 12주 및 26주 후에는 유의한 차이가 없었다. 다중회귀분석법의 단계별 투입방식을 이용하여 세포의 침윤율을 시간의 경과와 표면 처리여부에 따라 상관관계를 분석한결과, 세포 침윤율은 시간의 경과 및 표면처리를 하게 됨에 따라 감소하는 경향이 있었다. 조직 반응율의 정도도 침윤율과 유사한 양상을 나타내었다. 이상의 결과, 생체합금의 표면처리에 따라 골반응의 정도가 유의한 차이가 있었으므로 내고정 기구의 제작을 위해서는 보다 생체 적합성이 양호한 제작방법의 개발이 요구될 것으로 사료되었다.