• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.735-751
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• 1996

An ultimate goal of periodontal therapy is to stop the disease process and to regenerate a functionally-oriented periodontium destroyed as a result of periodontal disease. The purpose of this study was to observe the effect of grafting granulation tissue obtained from extraction socket on the regeneration of horizontal furcation defect. Six dogs were used in this study. All mandibular first and third premolars were extracted. At 2, 3, and 5 days after extraction, tissues were obtained from extraction socket of 1 mongrel dog and examined by light microscope. Granulation tissue obtained at 5 days after extraction was chosen as the graft material. Five days later, horizontal furcation defects were created surgically at mandibular second and fourth premolars in the right and left side of the 5 beagle dogs. The entrance area of the artificially prepared "key hole" defects were about $3\;4mm^2$. By random selections, 2 exposed furcation defects were grafted with granulation tissue obtained from extraction socket as experimental group and 1 furcation defect was as control. The flaps were replaced to their original position and sutured with 4-0 chromic cat-gut. Three dogs were sacrificed 4 weeks and two dogs 8 weeks after surgery, and the prepared specimens were examined by light microscope. At 4 weeks, furcations were filled with epithelial lining and fibrous connective tissue infiltrated with chronic inflammatory cells. New bone formation was observed in all groups. Only experimental group showed new cementum formation. At 8 weeks, new cementum, functional arrangement of new PDL fiber, root resorption, and some ankylotic union of newly formed alveolar bone and root surface were observed in all groups. Experimental group showed that epithelial downgrowth was inhibited and new bone formation was more active compared to control. The success rate of the furcation defect healing was higher in experimental group than control. These results suggested that grafting of granulation tissue obtained from extraction socket which combined with reconstructive periodontal flap surgery may promote periodontal regeneration of horizontal furcation defect.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.143-148
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• 2005

Chemotactic migration of bone forming cell, osteoblast, is an important event during bone formation, bone remodeling, and fracture healing. Migration of cells is mediated by adhesion receptors, such as integrins, that link the cell to extracellular matrix ligands, type I collagen, fibronectin, laminin and depend on interaction between integrin and extracellular ligand. Our study was designed to investigate the effect of extracellular matrix like fibronectin, laminin, type I collagen on migration of osteoblast. Migration distance and speed of MC3T3-E1 cell on extracellular matrix-coated glass were measured for 24 hours using 0.01% type I collagen, 0.01% fibronectin, 100 microliter/ml laminin. The migration distance and speed of MC3T3-E1 cell was compared using a video-microscopy system. To determine migration speed, cells were viewed with a 4 phase- contrast lens and video recorded. Images were captured using a color CCD camera and saved in 8-bit full-color mode. The migration distance on 0.01% type I collagen or 0.01% fibronectin was longer than that on $100{\mu}l/ml$ laminin-coated glass. The migration speed on fibronectin-coated glass was 68 micrometer/hour which was fastest. The migration speed on type I collagen-coated glass was similar with that on fibronectin-coated glass. The latter two migration speeds were faster than that on no-coated glass. On the other hand, the average migration speed on laminin-coated glass was 37micrometer/hour and not different from that of control group. In conclusion, the extracelluar matrix ligands such as type I collagen and fibronectin seem to play an important role in cell migration. The type I collagen or fibronectin coated scaffold is more effective for migration of osteoblast in tissue engineering process.

• Archives of Plastic Surgery
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• v.39 no.2
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• pp.118-123
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• 2012

Background : An area of the skull exposed by burn injury has been covered by various methods including local flap, skin graft, or free flap surgery. Each method has disadvantages, such as postoperative alopecia or donor site morbidities. Due to the risk of osteomyelitis in the injured skull during the expansion period, tissue expansion was excluded from primary reconstruction. However, successful primary reconstruction was possible in burned skull by tissue expansion. Methods : From January 2000 to 2011, tissue expansion surgery was performed on 10 patients who had sustained electrical burn injuries. In the 3 initial cases, removal of the injured part of the skull and a bone graft was performed. In the latter 7 cases, the injured skull tissue was preserved and covered with a scalp flap directly to obtain natural bone healing and bone remodeling. Results : The mean age of patients was $49.9{\pm}12.2$ years, with 8 male and 2 female. The size of the burn wound was an average of $119.6{\pm}36.7cm^2$. The mean expansion duration was $65.5{\pm}5.6$ days, and the inflation volume was an average of $615{\pm}197.6mL$. Mean defect size was $122.2{\pm}34.9cm^2$. The complications including infection, hematoma, and the exposure of the expander were observed in 4 cases. Nonetheless, only 1 case required revision. Conclusions : Successful coverage was performed by tissue expansion surgery in burned skull primarily and no secondary reconstruction was needed. Although the risks of osteomyelitis during the expansion period were present, constant coverage of the injured skull and active wound treatment helped successful primary reconstruction of burned skull by tissue expansion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.314-318
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• 2009

The aim of this study was to evaluate the clinical applicability of a ridge splitting technique for reconstruction of narrowed edentulous alveolar ridges for dental implantation. 41 patients with 47 edentulous areas were included in this study. After corticotomy of a rectangular buccal segment and about 3-4 weeks healing period, the alveolar ridge was splitted, implant was placed. The initial ridge width varied between 2.5 and 7.0mm, average was 3.99mm. 68 dental implants were placed, and the gap between the implants and the bone is filled with various bone graft material, or none. All splitted sites showed sufficient bone volume for insertion of the implants at the moment of implantation. Over 1 year of follow-up period, five implants(7.3%) had mobility in two patients, among them, 2 implants(2.9%) sustained infection and removed. And any other complications were not noted. Our conclussion is that ridge splitting of the narrow edentulous area is a reliable and safe procedure in horizontally deficient ridges.

• Journal of Periodontal and Implant Science
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• v.33 no.1
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• pp.61-77
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• 2003

The major goals of periodontal therapy are the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. Bone graft & guided tissue are being used for the regeneration of destroyed periodontium these days. Non-resorbable membranes were used for Guided tissue regeneration in early days, however more researches are focused on resorbable membranes these days. The aim of this study is to evaluate the osteogenesis of paradioxanone membrane on the calvarial critical size defect in Sprague Dawley rats. An 8 mm diameter surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into three groups: Untreated control group, Biomesh(R) group and paradioxanone group. The animals were sacrificed at 4, 8 and 12 weeks after surgical procedure. The specimens were examined by histologic, histomorphometric analyses. The results are as follows: 1. In histological view on Biomesh(R), no visible signs of resorption was observed at 4 weeks but progressive resorption was observed at 8 weeks through 12 weeks. Paradioxanone membrane expanded at 4 weeks, and rapid resorption was observed at 8 weeks. In both the membranes, inflammatory cells were observed around them. Inflammatory cells decreased with time but were still present at 12 weeks. More inflammatory cells were observed in paradioxanone membranes than in Biomesh(R) membrane. 2. The area of newly formed bone in the defects were 0.001${\pm}$0.001, 0.006${\pm}$0.005, 0.002${\pm}$0.003 at the 4 weeks, 0.021${\pm}$0.020, 0.133${\pm}$0.073, 0.118${\pm}$0.070 at the 8 weeks and 0.163${\pm}$0.067, 0.500${\pm}$0.197, 0.487${\pm}$0.214 at the 12 weeks in the control group, Biomesh(R) group and experimental group respectively. Compared to the control group, Biomesh(R) group displayed significant differences at 4,8, and 12 weeks and the paradioxanone group at 8 and 12 weeks.(P<0.05)

• Journal of Periodontal and Implant Science
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• v.46 no.6
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• pp.362-371
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• 2016

Purpose: The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate ($LS_2$) and zirconium oxide ($ZrO_2$) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. Methods: Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). Results: The best cell migration was observed on $ZrO_2$ ceramic. Cell adhesion was also drastically lower on the polished $ZrO_2$ ceramic than on both the raw and polished $LS_2$. Evaluating various surface topographies of $LS_2$ showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. Conclusions: Our results demonstrate that a biomaterial, here $LS_2$, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of $LS_2$ and $ZrO_2$ ceramic showed that $LS_2$ was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.196-203
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• 2010

This study aimed to examine the effect of microcurrent stimulation on expression of Bone Morphogenetic Protein(BMP) 4 after tibia fracture in rabbits. The twenty four adult 6 month old New Zealand white rabbits weighting 2.5~3.5 ㎏ were used. Twenty four rabbits with tibia fracture were randomly divided into control and experimental groups. Each group was divided into four subgroups, based on the duration of the experiment (3, 7, 14, 28 days). The experimental groups received microcurrent stimulation of 20~25 ${\mu}A$ intensity with surface Ag-AgCl electrode (diameter 1cm, Biopac, U.S.A.) for 24 hours a day. Cathode of the microcurrent stimulator located on the tibia directly, anode of it did on the gastrocnemius muscle. After evaluation, the test results are as follows: Comparisons of immunohistochemical observation of BMP-4 in 7 days after tibial fracture show that there was shown to be a moderate positive reaction (++) on concentric circles of Harversian system and the interstitial lamella in the control group, while there was a very strong positive reaction () on concentric circles of Harversian system and interstitial lamellain the experimental group. These results suggest that applying non-invasive constant microcurrent stimulation on fractured bone is helpful to bone healing.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.821-838
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• 1999

On the basis of the evidences that electrical stimulation could enhance proliferation and differentiation of bone cells and promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on human periodontal ligament cells and gingival fibroblasts in vitro, which also have important roles in regeneration of periodontium, and to evaluate the potential of clinical application of electrical stimulation. Human periodontal ligament cells and gingival fibroblasts were primarily cultured from the root surface of extracted premolar and the adjacent gingiva without periodontal diseases. In control group, the cells ($5{\times}10^4$ cells/ml)were incubated only in Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum. In test groups, electrical stimulation was given at the current intensity of $0.25{\mu]A$(test group 1), $1.0{\mu}A$(test group 2), and $2.5{\mu}A$(test group 3) for 12 hours to the same culture media with the control group. After 12 hour exposure of electrical stimulation, the cells were incubated for 2 and a half days(60 hours), and then each group of cells was analyzed for cell proliferation, protein level, and activity of alkaline phosphatase. The results were as follows ; 1. The Rate of cell proliferation of every test group increased significantly in both periodontal ligament cells and gingival fibroblasts, and in periodontal ligament cells, test group 3 showed significantly increased proliferation compared to the other test groups(p<0.05). 2. In the protein levels, neither periodontal ligament cell nor gingival fibroblast showed statistically significant differences between control and test groups. 3. The activity of alkaline phosphatase in periodontal ligament cells increased significantly in all test groups(p<0.05), but there were no significant differences between 3 test groups. In gingival fibroblasts, the activity of alkaline phosphatase increased significantly only in test group 3(p<0.05). From the above results, it is concluded that electrical stimulation may have beneficial effects on the regeneration of destructed periodontal tissue in regard of the stimulation of periodontal ligament cells and gingival fibroblasts as well as electrically stimulated bone formation that has been known, and that electrical stimulation may have the potential of clinical application.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.531-535
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• 2016

Phlomis umbrosa and Dipsacus asperoides are distinct species, even though they have a similar appearance. Dipsacus asperoides is used as a Chinese medicinal plant for and has bone strengthening and fracture healing but Phlomis umbrosa has no effect on bone growth. Recently, these plants were used in children's food to improve their bone growth, without distinction in food. Intakes of Dipsacus asperoides in food may be dangerous, because it has never been used in food and its safety has never been tested in humans. We developed liquid chromatography with tandem mass spectrometry method to distinguish these plants in food. The method was validated for linearity, limits of detection, limits of quantification, accuracy and precision. In 5 of 17 samples, we identified Dipsacus asperoides, containing loganin $0.19-14.45{\mu}g/mL$, sweroside $0.13-4.61{\mu}g/mL$ and akebia saponin D $0.59-19.29{\mu}g/mL$. The developed method might be useful to identify Dipsacus asperoides in adulterated food.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.41-52
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• 2009

The surface treatment of titanium implant could bring out the biochemical bonding between bone and implant. The purpose of this study was to evaluate the biomechanical bone response of Mg-ion implanted implants with plasma source ion implantation method. Twelve New Zealand white rabbits were included in this study. Each rabbit received one control fixture (blasted with resorbable blasting media, RBM) and three types of Mg ion implanted fixtures in tibiae. The implants were left in place for 6 weeks before the rabbits were sacrificed. Removal torque value and resonance frequency analysis (ISQ) were compared. The repeated measured analysis of variance was used with $P{\leq}0.05$ as level of statistical significance. ISQ was not different among all groups. However, the ISQ was increased after 6 weeks healing. The group had lowest ISQ value showed the greatest increment. Mg-1 implants with 9.4% retained ion dose showed significantly higher removal torque value than that of the other implants. From this results, it is concluded that the Mg-1 implants has stronger bone response than control RBM surface implant.