• The Journal of Korean Academy of Prosthodontics
• /
• v.36 no.6
• /
• pp.816-831
• /
• 1998

Bony fixation of implants during the early phase of healing is important in order to get secondary stability of the implant assuring the success of the treatment. Because the successful placement of the implant is limited by the quality and quantity of bone, other agents which stimulate bone formation in the peri-implant spaces has been illustrated. Platelet-derived growth factor (PDGF) has been shown to regulate DNA and protein synthesis in bone cells in vitro and to interact synergistically to enhance soft tissue wound healing in vivo. The purpose of this study was to evaluate bone promotion around implants which were augmented with sagittal split osteotomy or autogenous veneer bone graft using the platelet derived growth factor(PDGF). After placement of newly designed twenty four screw-type implants, which were 12mm in length and 4mm in diameter in 6 dogs. $4{\mu}g$ of PDGF B/B was applied with surgicel carriers. The dogs were sacrificed at 3 days, 1, 2, 3, 6, and 12 weeks after implantation. Specimens were examined clinically, radiographically, histologically, and histomorphometrically. The results were as follows: 1. Clinically and radiologically, there was no significant difference in bone formation and healing pattern between experimental and control group. 2. In autogenous veneer bone graft group, bone formation was observed at 1st week in the experimental groups but 2nd week in the control groups. At 3rd week, the expeimental groups showed more bone formation comparing to the control groups. 3. In sagittal split osteotomy group, bone formation was observed at 1st week in both groups. But the experimental groups showed more bone formation comparing to the control groups after 2nd week. 4. The bone growth rate of experimental group was more rapid than that of control group. These results indicated that PDGF did not affect the initiation of new bone formation, but it accelerated the bone formation at the early period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.3
• /
• pp.228-238
• /
• 2005

Purpose: Several cryoprotectants are in use to help the survival of cells during cryopreservation of bone in maxillofacial region. Among them, $Me_2SO$(dimethyl sulfoxide), EG(ethylene glycol), sucrose were used for experimentally created defects with accompanying cryopreserved bone graft in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Materials and methods: Nine rabbits were used as experimental animals. Surgical defects were created on the distal femoral heads and mesial tibial heads of each animal using trephine drill(5mm diameter and 5mm length). The harvested bones were cryopreserved in $-80^{\circ}C$ refrigerator for one week. The defects were filled with cryopreserved bone with cryoprotectants as experimental groups and cryopreserved bone without cryoprotectant as control. Then, the animals were sacrificed at 1, 2, and 3 weeks after surgery. With Goldner's modified Masson trichrome staining and semiautomatic image analysis system, we observed the change of the cells and bone formation. Results: After bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the control were somewhat weaker than that of the experiments. Especially $Me_2SO$+sucrose group was the best in bone formation and bone remodeling. $Me_2SO$ group was more than that of EG group in bone fomation. Sucrose seems to be helpful in survival of the bone cell. Histologic findings showed superior bony quantity and quality in experimental groups than that in control. Conclusions: The data from this study provides the basis for future studies for evaluating the effect of cryoprotectants in the cryopreservation of bone and clinical study for predictable use of these agents.

• Journal of Digital Convergence
• /
• v.11 no.9
• /
• pp.365-370
• /
• 2013

This mouse calvarial defected model is frequently used for new scaffold development in the bone regeneration. Most experiments are carried out in this way by measuring the bone regeneration of mouse calvaria defected area. As a next step, hematoxylin and eosin staining is analyzed by sacrificing mice On the other hand, the quantitative analysis for bone regeneration is carried out by micro computed tomography. However, there are several drawbacks with the micro computed tomography. That is, it takes a long time and it is quite expensive for bone regeneration quantitative analysis. This study was performed by simply measuring the quantity of bone regeneration in mouse clavaira defected area on two-dimensional digital x-ray images via Image J. Consequentially, this experimental method by using J program might help bio-technologist researcher regarding new bone regeneration by comparing the quantity of bone regeneration quickly and precisely as well.

• Archives of Plastic Surgery
• /
• v.38 no.1
• /
• pp.15-18
• /
• 2011

Purpose: The anterior iliac crest is a common source for autologous cancellous bone graft. For patients who have previously received cancellous bone grafts from bilateral anterior iliac crests, there may be concerns of whether a sufficient quantity of autologous cancellous bone remains for additional grafts without harvesting it from other sites, such as the posterior iliac crest. Methods: We experienced 3 cases of reharvesting in 2 patients. The diagnosis of the first patient was bilateral facial cleft number 3. This patient received bilateral side cleft alveoloplasty with corticocancellous bone graft from the both anterior iliac crest respectively by a previous surgeon. This patient then needed reharvesting of the anterior iliac crest cancellous bone to correct an ongoing skeletal problem for the bilateral cleft. The other patient had bilateral incomplete cleft of the primary palate. This patient received left side cleft alveoloplasty with cancellous bone graft from the right anterior iliac crest. Before the patient could receive the alveoloplasty on the other side, a radial head osteotomy and cancellous bone graft was performed by orthopedic surgeons who then used the remaining left iliac crest in order to treat a pulled elbow. For the completion of the right side cleft alveoplasty, the anterior iliac crest cancellous bone needed to be reharvested. Prior to the reharvesting, a preoperative computed tomography scan of the pelvis was obtained to assess the maturity of the donor site regeneration. The grafts were then taken from site where a greater amount of regeneration was evident. Results: Long term follow ups showed that the grafts were successfully taken. This sufficient volume was obtainable 14 months after the first harvest. Conclusion: Satisfactory results were achieved after the reharvesting of iliac cancellous bone. Thus, it appears that the reharvesting of the iliac bone is a possible alternative to multiple site grafting, use of allograft or bone substitute materials.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.1
• /
• pp.49-58
• /
• 2008

Objective: The Purpose of the study was to investigate the bone morphogenic protein expression of rhBMP-2(recombinant human bone morphogenic protein-2) as singnaling molecule and ${\beta}-TCP$(Tricalcium phosphate) as a bone substitute and carrier medium of rhBMP-2. Materials and Methods: 16 rabbits divided into 2 group of each 8 rabbit. Two standardized bone defect, round bilateral defect was made in the cranium of the 8 rabbit of first group, and was grafted with $150{\sim}500{\mu}m$ diameter ${\beta}-TCP$ 0.25g in one side, which was soaked with rhBMP-2, and autogenous bone was grafted on another side as a positive control. Second group of 8 rabbit, only ${\beta}-TCP$ was grafted with same size and same manner. After 2, 4, 8, and 12 weeks, specimen was taken for microscopic immunohiostochemical and histomorphometric analysis. Result: Grafting ${\beta}-TCP$ with rhBMP show the early formation of the bone regenerative factor (BMP-4) and more quantity of new bone formation than only use of ${\beta}-TCP$ (8,12 week), even show less new bone formation than autogenous bone. Conclusion : The experimental study result that ${\beta}-TCP$ graft combination with rhBMP-2 as a delivery system is an effective with osteoinductive capacity and biodegradable properties, so that provide clinical availibility of composite use in reconstruction of bony defect.

• Imaging Science in Dentistry
• /
• v.50 no.3
• /
• pp.217-226
• /
• 2020

Purpose: The purpose of this study was to analyze the quantity and quality of the mandibular anterior alveolar bone in terms of alveolar width, density, and total alveolar height (TAH) based on dental status, gender, and age. Additionally, this study aimed to quantitatively evaluate the available alveolar height for graft harvesting (AHGH) and examine its variability based on the aforementioned factors. Materials and Methods: This retrospective cone-beam computed tomographic study included a total of 100 subjects. On the basis of gender, dental status, and age, the scans were divided into 3 primary groups and 8 subgroups. The mandibular alveolar width and density were measured 5 mm mesial to the mental foramen bilaterally and at the midline. The TAH was measured at the midline, and the AHGH was measured as the midline distance between 5 mm apical to the root of the canines and 5 mm superior to the lower border. Results: The mandibular alveolar width was statistically similar between dentulous and edentulous patients (P>0.05). A significantly greater density was observed at the midline in edentulous patients (P<0.05). The TAH was significantly greater in edentulous male patients than in edentulous female patients (P<0.05). Dentulous and male patients had significantly greater AHGH than edentulous and female patients, respectively (P<0.05). Conclusion: Based on the data evaluated in this study, it can be concluded that the mandibular symphyseal area has adequate bone quality and quantity for bone graft harvesting for dental implant therapy.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.10a
• /
• pp.13.2-13.2
• /
• 2011

뼈의 역학기능을 예측하는 인자(predictive factor) 로서 골밀도(BMD)만으로는 충분하지 않다는 최근의 임상결과는, 골밀도 이외의 새로운 뼈의 강도 및 골절리스크를 지배하는 인자의 중요성을 보여준다. 이와 같은 골역학기능에 대한 골밀도 이외의 부가적인 지배인자를 골질(bone quality)이라고 하는데, 다양한 골질관련인자(bone quality-related factor) 중 하나의 지표로서 뼈의 주성분인 생체아파타이트(BAp)의 결정학적 방향성에 주목, 대표적인 경조직 질환을 해석하였다. 파골세포결손에 의해 대리석증을 유발하는 op/op마우스는 골밀도의 변화뿐만 아니라, 골질의 유의한 변화가 있었다. 즉, 이와 같은 결과는 파골세포결손에 의한 조골세포의 활성저하의 의해 골질이 저하됨을 시사하는 결과이며, 파골세포 과잉의 의해 골다공증을 유발하는 OPG-KO마우스는 골밀도가 급격히 저하됨과 동시에, BAp배향성도 급격히 낮아졌다. 즉, 골대사회전의 상승에 따른 섬유성골(woven bone)의 형성에 의해 BAp의 결정성장이 억제되며, 그 결과 BAp배향성이 저하된다고 사료된다. 이상, 본 연구에서는 대표적인 골 질환조직을 각각의 정상골과 비교함으로써, 골양(BMD)의 변화뿐만 아니라 골질(BAp배향성)의 변화를 발견하였다. 이와 같은 변화는 골질지표로서 BAp배향성이 유효하다는 것을 강하게 시사한다. 따라서 본 연구에 의해 얻어진 견해는 경조직 질환의 병리해명에 적용 가능함과 동시에, 경조직 질환의 진단 응용이나 치료약 개발, 임플란트 개발 등 폭넓은 분야에 유용하다고 할 수 있다.

• The Journal of Korean Academy of Prosthodontics
• /
• v.33 no.2
• /
• pp.317-334
• /
• 1995

The purpose of this study was to compare the bone formation, maturation around HA-and titaniumcoated dental implants in dog. 5 hydroxyapatite coated IMZ implants and 5 titanium coated IMZ implants were placed into the previously extracted site in the mandible of 5 adults dogs. All dogs were injected intravenously Tetracycline, Alizalin red S, and Calcein for bone fluorescent labelling, After the experimental period of 16weeks, the dogs were sacrificed and tissue samples around the implants were obtained. Microscopic observations(ligth, polariged and fluorescence microscope), morphometric analysis, line profile with EPMA, and quantitative analysis for Ca,P, and Ti were performed. The results were as follows ; 1. Bone maturations around the implants were relatively lower than those of natural teeth. No significant differences in bone maturation and remodeling patterns were observed between the two implants groups. 2. Calcification of bone surrounding the implants was initiated in 8-11 weeks for HA-coated implants, while it took 11 weeks or more for Ti-coated implants. 3. Bone-to-implants contact ratio of 82.63% was recorded for HA-coated group and 72.25% for titanium coated group, with no significant difference between the two groups. 4. Bone around the implants exhibited reduced quantity of Ca and P in the $100{\mu}m$ region relative to natural teeth, while the rest of the regions showed no statistical differences. No significant differences were found between the two implant groups. 5. There was a separation of HA layer from the implant core and subsequent infiltration of inflammatory cells into the resulting space in the HA-coated implants, and evidences of phagocytosis of HA particles by macrophages. Bone calcification was more rapid around HA-coated implants compared to titanium-coated implants, but HA coated implants did not show any significant differences either in the degree of calcification or the bone-to-implant contact ratio over Ti coated implants. HA coated implants may have complications associated with HA absorption and separation of HA layer from the implant core.

• Journal of Periodontal and Implant Science
• /
• v.38 no.sup2
• /
• pp.355-362
• /
• 2008

Purpose: The carrier for the delivery of bone morphogenetic proteins(BMPs) should also serve as a scaffold for new bone growth. In addition, predictable bone formation in terms of the volume and shape should be guaranteed. This study evaluated the ectopic bone formation of recombinant human BMP-2(rhBMP-2) using a micro macroporous biphasic calcium phosphate (MBCP: mixture of ${\beta}TCP$ and HA) block as a carrier in a rat subcutaneous assay model. Materials and Methods: Subcutaneous pockets were created on the back of 40 male Sprague-Dawley rats. In the pockets, rhBMP-2/MBCP and MBCP alone were implanted. The blocks were evaluated by histological and histometric parameters after a healing interval of 2 weeks (each 10 rats; MBCP and rhBMP-2/MBCP) or 8 weeks (each 10 rats; MBCP and rhBMP-2/MBCP). Results: The shape and volume of the block was maintained stable over the healing period. No histological bone forming activity was observed in the MBCP alone sites after 2 weeks and there was minimal new bone formation at 8 weeks. In the rhBMP-2/MBCP sites, new bone formation was evident in the macropores of the block. The new bone area at 8 weeks was greater than at 2 weeks. There was a further increase in the quantity of new bone with the more advanced stage of remodeling. Conclusions: A MBCP block could serve as a carrier system for predictable bone tissue engineering using rhBMPs.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.5
• /
• pp.444-450
• /
• 2007

In general, labiolingual or buccolingual widths of residual alveolar bone are insufficient in edentulous area, because of alveolar resorption. Horizontal augmentation is bone graft procedure with a view to reinforcing horizontally insufficient bone quantity for installation of implants. The standard method is taking appropriate amount of block bone from intraoral or extraoral autogenous bone, and solid fixation with screws or mini-plate on labial or buccal side of residual alveolar bone. The purpose of this study is to discuss clinical usefulness of horizontal augmentation with autogenous block bone by observation and analysis of course of 41 implants installed to 12 patients by horizontal augmentation in Seoul National University Bundang Hospital from July, 2002 to December, 2005. The mean age of patients is 52.7, from 19 to 70, and the number of men and women is each 2 and 10. Block bone was taken from symphysis, body, ramus of mandible or iliac bone. And 6 types of implants were installed simultaneously or not, the diameters of implants are from 3.3 to 5.5mm, the lengths are from 8 to 15mm. The operator added artificial bone grafting material and optionally covered with membrane. The mean periods of observation after operation and final prosthetics were 28.6 and 17.0 months. As a result, 40 among 41 implants survived, the survival rate was 97.6%. Average 0.9mm crestal resorption was observed at final point of time by periapical view of each patients. Major complication related to the procedure was numbness in 7 patients.