• Journal of Periodontal and Implant Science
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• v.45 no.3
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• pp.111-119
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• 2015

Purpose: The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs. Methods: The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution ($30{\mu}g/0.1mL$). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation. Results: At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue. Conclusions: The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.232-247
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• 2005

Purpose. The purposes of this investigation were to discover the possibility of clinical application in the areas of dental implants and bone grafts by investigating the bone formation histologically around specimen which was depending on the intensity of magnetic field of neodymium magnet inside of the specimens. Material and method. 1. Measurement of magnetic intensity - placed the magnet inside of the specimen, and measured the intensity of magnetic field around the 1st thread and 3rd thread of specimen 20 times by using a Gaussmeter(Kanetec Co., Japan). 2. Surgical Procedure - Male rabbit was anesthetised by constant amount of Ketamine (0.25ml/kg) and Rompun (0.25ml/kg). After incising the flat part of tibia, and planted the specimens of titanium implant, control group was stitched without magnet, while experimental groups were placed a magnedisc 500(Aichi Steel Co., Japan) or magnedisc 800(Aichi Steel Co., Japan) into it, fixed by pattern resin and stitched. 3. Management after the surgery - In order to prevent it from the infection of bacteria and for antiinflammation, Gentamycin and Ketopro were injected during 1 week from operation day, and dressed with potadine. 4. Preparation of histomorphometric analysis - At 2, 4 and 8 weeks after the surgery, the animals were sacrificed by excessed Ketamine, and then, specimens were obtained including the operated part and some parts of tibia, and fixed it to 10% of PBS buffer solution. After embedding specimens in Technovit 1200 and B.P solution, made a H-E stain. Samples width was 75$\mu$m . In histological findings through the optical microscope and using Kappa image base program(Olympus Co. Japan), the bone contact ratio and bone area ratio of each parts of specimens were measured and analyzed. 5. Statistical analysis - Statistical analysis was accomplished with Mann Whitney U-test. Results and conclusion. 1. In histomorphometric findings, increased new bone formation was shown in both control & experimental groups through the experiment performed for 2, 4 & 8 weeks. After 4 weeks, more osteoblasts and osteoclasts with significant bone remodeling were shown in experimental groups. 2. In histomorphometric analysis, the bone contact ratios were 38.5% for experimental group 1, 29.5% for experimental group 2 and 11.9% for control group. Experimental groups were higher than control group(p<0.05) (Fig. 6, Table IV). The bone area ratios were 60.9% for experimental group 2, 46.4% for experimental group 1 and 36.0% for control group. There was no significantly statistical difference between experimental groups and control group(p<0.05) (Fig. 8, Table VII) 3. In comparision of the bone contact ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group at the 1st thread (p<0.05) and experimental group 1 (1.8mT) was higher than control group at the 3rd thread(p<0.05) (Fig. 7, Table V, VI). 4. In comparision of the bone area ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group and experimental group 1 (4.0mT) at the 1st thread(p<0.1) and experimental group 2(4.4mT) was higher than experimental group 1 (1.8mT) at the 3rd thread(p<0.1) (Fig. 9, Table IX, X). Experiment group 2 was largest, followed by experiment group l and control group at the 3rd thread of implant. There was a significant difference at the 1st thread of control group & experiment group 2, and at 1st thread & 3rd thread of experiment group 1 & 2, and not at control group experiment group 1.(p<0.1)

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.5
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• pp.294-301
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• 2013

Purpose: The purpose of this study is to assess the effectiveness of beta-tricalciumphosphate (${\beta}$-TCP) as a bone graft material on new bone formation and regeneration of mandible bone defect around dental implants. Methods: Both mandibular sites of ten rabbits were exposed. The experimental subjects were divided into two groups. Rabbits in the control group (right site of the mandible) had dental implants around cortical bone defects, without treatment, while, in the experimental group (left site of the mandible), ${\beta}$-TCP was grafted into the bone defect around the implant. Rabbits were sacrificed after one, two, three, four, and eight weeks, and histomorphometric evaluation and analysis of the bone implant contact rate were performed using an optical microscope. Results: Bone formation rates in the experimental group were greater than those in the control group from one to eight weeks, and percentages of implant surface contacted to bone were greater in the experimental group than in the control group from three weeks after implantation. Conclusion: These results suggest that the bone formation activity around dental implants was increased by osteoconduction activity of ${\beta}$-TCP.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.165-180
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• 1997

The purpose of this study was to observe bone apposition and marginal bone loss and to check the possibility of success on titanium implant, HA coated implant and the implant with natural coral that were place immediately after teeth extraction in dogs. Experimental subjects were divided into 4 groups ; the 1st group is the titanium implant, second the HA coated implant, third the implant with natural coral, and the last the control group that was prepared in the extraction sockets. After 12 weeks, the dogs were sacrificed for visual observation and microscopic examination approaching histologic and histomorphometric analysis. The results were as follows : 1. Neither the infection nor the exposure of implant was found at the sites of all implant. 2. In a histomorphometric analysis, mean percentage of direct bone contact with the titanium implant was 80.7% and the HA coated implant showed 81.5% apposition, but the implant with natural coral showed 64.9% apposition(P<0.05). 3. In a microscopic examination, mature lamellated bone was found around the immediate implants and control group, while unabsorbed natural coral around the immediate implants with natural coral was found. 4. All immediate implant groups showed the loss of marginal bone in order from implant with natural coral, titanium implant, and HA coated implant. 5. Implant with natural coral that was placed by the type I interface of the Barzilay's classification immediately after teeth extraction showed low percentage of direct bone contact area, low success rate and a lot of marginal bone loss. Above results suggested that the immediate implants are osseointegrated successfully, although slightly marginal bone was loss.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.290-301
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• 2002

The purpose of this study was to evaluate new bone formation and healing process in rat calvarial bone defects using $BioMesh^{(R)}$. membrane and DFDB. Forty eight rats divided equally into 4 groups of 1 control group and 3 experimental groups. Standardized transosseous circular calvarial defects (8 mm in diameter) were made midparietally. In the control group, the defect was only covered with the soft tissue flap. In the experimental group 1, it was filled with DFDB only, in the experimental group 2, it was covered $BioMesh^{(R)}$. membrane only, and in the experimental group 3, it was filled DFDB and covered with membrane. At the postoperative 1, 2, 4, 8 weeks, rats were sacrificed and histologic and histomorphometric analysis were performed. These results were as follows. In histomorphometric analysis, It showed the greatest amount of new bone formation through experimental in the experimental group 3 (P<0.001). The amount of new bone formation at the central portion of the defect was greater in the experimental group 3 than experimental group 2. $BioMesh^{(R)}$. membrane began to resorb at 1 week and resorbed almost completely at 8 weeks after operation. The collapse of membrane into the defect was observed through the experimental periods in the experimental group 2. In the area of collapsed membrane, new bone formation was restricted. These results suggest that maintenance of some space for new bone to grow is required in the use of $BioMesh^{(R)}$. membrane alone in the defect. It is also thought that use of the membrane may promote new bone growth in DFDB graft.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.90-94
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• 2008

The purpose of this study was to investigate the effects of immediate non-functional loading by analyzing histomorphology around the implant tissues in dogs. Five eight- to nine-month-old full-grown dogs weighing around 12 kg were used in the study. Group I (control group) comprised those in which delayed loading was applied to the right side of the mandible, and Group II (experimental group) consisted of dogs in which immediate loading was performed on the left side of the mandible. Resorbable blast media (RBM)-treated double-threaded US III implants measuring 3.5 mm in diameter and 11 mm long were used in the study. Each animal received four implants in each group, for a total of 40 implants. Cemented type abutments were used after implantation. An 8-week period was allowed for bone healing and an abutment was placed after exposing the periosteum for loading. An implant sample was obtained from bone blocks taken when the dogs were killed at 16 weeks after loading. A Mann-Whitney U-test was performed to evaluate statistical significance. Student's t-test was used for the histological evaluation. The bone formation ratio in Groups 1 and 2 was 88.23 and 86.41%, respectively. No significant difference in new bone formation was observed in the two groups. As no significant difference was seen in new bone formation between the delayed and immediate loading groups, early loading might be possible after implant placement.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.528-538
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• 2014

PURPOSE. The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS. The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS. In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness ($0.07{\mu}m$ in Bio-Oss group Vs. $0.08{\mu}m$ in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness ($8.35{\mu}m$ in Bio-Oss group Vs. $13.12{\mu}m$ in AutoBT group) (P=.025). CONCLUSION. AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.6
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• pp.332-342
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• 2019

Objectives: Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation. Materials and Methods: This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee. Results: All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae. Conclusion: Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.172-181
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• 2023

Purpose: To investigate the effect of epidermal growth factor (EGF) with collagen matrix (CM) for increasing gingival thickness. Materials and Methods: In five mongrel dogs, bilateral gingival defects were surgically made on the maxillary canines. After two months, either a subepithelial connective tissue graft (group SCTG) or CM with EGF (0.1 ug/ml, group EGF) was grafted, and the flap was coronally positioned to cover the graft materials. The animals were sacrificed after three months. Intraoral scanning was performed for soft tissue analysis. Histologic and histomorphometric analyses were performed. Result: Two animals exhibited wound dehiscence during the healing phase, leaving three for analysis. No statistically significant difference was found in soft tissue changes (P>0.05). The level of gingival margin (GM) increased in both groups (1.02±0.74 mm in group SCTG vs. 1.24±0.83 mm in group EGF). Linear increases at the GM pre-augmentation in the soft tissue profile were 1.08±0.58 mm in group SCTG and 0.96±0.73 mm in group EGF. Histomorphometric parameters (keratinized tissue height, tissue thickness, and rete peg density) were not significantly different between the groups (P>0.05). Conclusion: EGF loaded onto CM led to comparable gingival phenotype enhancement to SCTG.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.635-648
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• 2005

The procedure that enhances osteogenesis and shortens the healing period is required for successful implant therapy. It has been introduced that osteogenesis is enhanced by the generation of electric field. Many researchers have demonstrated that application of electric and electromagnetic field promote bone formation. It also has been shown that electrical stimulation enhances peri-implant bone formation. Recently, several investigators have reported that noninvasive electrical stimulation using negatively charged electret such as polytetrafluoroethylene(PTFE) promotes osteogenesis. Therefore, we were interested in the effect of noninvasive electrical stimulation using negatively charged electret on the periimplant bone healing. After titanium implant were installed in the proximal tibial metaphysis of New Zealand white rabbit, negatively charged PTFE membrane fabricated by corana dischage was inserted into the inner hole of the experimental implant and noncharged membrane was applied into control implant. After 4 weeks of healing, histomorphometric analysis was performed to evaluate peri-implant bone response. The histomorphometric evaluations demonstrated experimental implant tended to have higher values in the total bone-to-implant contact ratio(experimental ; $49.9{\pm}13.52%$ vs control ; $37.5{\pm}19.44%$) , the marrow bone contact ratio(experimental ; $34.94{\pm}13.32%$ vs control ; $24.15{\pm}13.69%$), amount of newly formed bone in the endosteal region(experimental ; $1.00{\pm}0.30mm$ vs control ; $0.61{\pm}0.24mm$) and bone area in the medullary canal(experimental ; $13.55{\pm}4.98%$ vs control ; $9.03{\pm}3.05%$). The mean values of the amount of newly formed bone(endosteal region) and bone area(medullary canal) of the experimental implant demonstrated a statistically significant difference as compared to the control implant(p<0.05). In conclusion, noninvasive electrical stimulation using negatively charged electret effectively promoted peri-implant new bone formation in this study. This method is expected to be used as one of the useful electrical stimulation for enhancing bone healing response in the implant therapy