• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.334-349
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• 1996

Regeneration of the periodontal tissue destroyed by periodontal disease is one of the final goals of periodontal therapy. In the past few years, periodontists have used various alloplastic grafting materials in an attempt to regenerate bone lost from periodontal disease. These materials have used widely because they have shown to be nontoxic, biologically compatible with surrounding host tissue and chemically similar to bone. The purpose of this study was to investigate the effect of Porous Resorbable Calcium Carbonate and Porous Replamineform Hydroxyapatite on the regeneration of the alveolar bone and the healing of roots transplanted into the periodontally diseased extraction sockets of dogs. The experimental chronic periodontitis was induced by elastic ligatures on the 2nd and 3rd mandibular premolars of 2 adult dogs for 8weeks after surgically creating periodontal defect. The extracted root were split in half along the long-axis, and the extend of plaque exposure was marked on the root surfaces with burs. The roots were inserted in extraction sockets with Porous Resorbable Calcium Carbonate(PRCC) in left side and with Porous Replaminefrom Hydroxyapatite(PRH) in right side. The flaps were sutured to cover the sockets completely. The animals were sacrificed after 12 weeks of healing, and the specimens were examined histologically. The results were as follows: 1. No inflammatory reactions were observed in either groups. 2. Hoot resorption was observed in both groups while the general outline of the roots were maintained. 3. PRCC was almost completely resorbed and replaced with new bone, while R.H.A. was not resorbed & remained encased in newly-formed C-T and alveolar bone. 4. PRH was encapsulated with alveolar bone which has been deposited from apical & lateral area of the sockets, while the coronal portion of the sockets were filled with C-T. 5. In both groups, the resorbed portions of the roots were replaced with new bone. These results suggest that either PRCC or PRH may not interfere with bone formation or healing in extraction sockets, and in some degree, retard the root resorption. Because the roots maintained in anatomy, we think that graft materials prevent the root resorption.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.97-100
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• 2010

Purpose: Epidermolysis bullosa is a rare genetic disease, characterized by the presence of extremely fragile skin and formation of recurrent blister resulting from even a minor mechanical injury. Squamous cell carcinoma (SCC) is recognized as a complication of the chronic scarring associated with dystrophic epidermolysis bullosa (DEB). When a soft tissue defect happens in a patient with epidermolysis bullosa, it is difficult to cover it with a skin graft or a flap. We describe the successful use of a pedicled deep inferior epigastric perforator flap for the reconstruction of SCC associated with DEB in the groin. Methods: A 29-year-old man diagnosed with DEB at birth sustained an ulcer increasing in the right groin for the last 7 months. Under general anesthesia, the mass lesion and lymph nodes were removed and the resulting defect was covered with a pedicled deep inferior epigastric perforator flap. Results: The flap survived completely and his postoperative course was uneventful. Histopathological examination revealed a SCC in the right groin and malignant tumor cells in the removed lymph nodes as well. Additional positron emission tomogram showed a malignant lesion in the ileocecal area with regional lymph node metastasis. The patient was referred to an oncologist for chemotheraphy, but the patient refused to take it. During a 4-month follow-up period, there was no recurrence in the right groin. Conclusion: We suggest that perforator flaps can be considered as a reliable alternative for the reconstruction of soft tissue defects in a patient with DEB.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.241-257
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• 2000

Autogenous periosteal grafts are an attractive alternative to existing barrier membrane materials since they meet the reqiurements of an ideal material. But no histological data are available on the effectiveness of periosteal membranes in the treatment of periodontal defects. The purpose of this study was to evaluate effect of autogenous periosteal graft on periodontal regeneration histologically. Class II furcation defects were surgically created on the second, third and the fourth premolars bilaterally in the mandibules of six mongrel dogs. The experimental sites were divided into three groups according to the treatment modalities; control group - surgical debridement only; Group I- autogenous periosteal membrane placement after surgical debridement; Group II-autogenous periosteal membrane placement after surgical debridement and bone grafting. The animals were sacrificed at 2, 4 and 12 weeks after periodontal surgery and the decalcified and undecalcified specimens were prepared for histological and histometrical analysis. Clinically all treated groups healed without significant problems. Under light microscope, at 2 weeks, control group showed significant apical epithelial migration and bone remodelling only below the notch area. But for the group I, II with autogenous periosteal graft, less apical migration of epithelium appeared and large amount of osteoid tissue showed above the notch area. Grafted periosteal membrane was indiscernable at 4 weeks, so periosteal membrane might be organized to surrounding tissues. Histometrically, at 4 and 12 weeks, all the test and control groups didn't show significant change of epithelial zone but new attachment level tended to be gained in the test groups than control group. These results suggest that autogenous periosteal grafts should be a good alternative for guided tissue regeneration.

• Journal of Chest Surgery
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• v.36 no.2
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• pp.63-72
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• 2003

Although a variety of synthetic vascular grafts are available in modern vascular surgery, no ideal prosthesis ha,4 yet been developed. Small-caliber vascular grafts with low flow, as used in the lower extremity, continue to become thrombosed at unacceptable rates. We have developed and evaluated the new antithrombogenic blood contacting surfaces in canine model. Material and Method: Two now antithrombogenic blood contacting surfaces(Polyvinylalcohol -Polyurethane(PVA-PU) blend and natural Graphite-polyurethane(G-PU) blend) have been developed and evaluated in canine model, using vascular grafts and patches. The luminal surfaces of the test vascular grafts(5 mm ID) were fabricated by dipping a glass rod in PVA-PU blend solution(50 % PVA) using phase separation method. Mongrel dogs of either sex weighing 18-22 kg were anesthetized by endotracheal intubation using halothane and their lungs were ventilated with a volume-cycled ventilator, Maintenance anesthesia with 0.5-1.0% halothane and supplemental oxygen was used. Two pairs were used for comparison in the bilateral femoral arteries for both vascular grafts(PVA-PU vs. PU) and vascular patches(G-PU vs. PU). Bilateral groin incisions were made and the arteries were exposed and clamped. After an excision of 1 cm of the artery between clamps, a grail of 2.5 cm in length was implanted end-to-end using 6-0 polypropylene suture. The vascular patch was implanted as a form of on-lay patch. Animals were sacrificed at 1, 2, 4, 6, 8 and 16 weeks for vascular grafts and 1, 2. 4 and 6 weeks for vascular patches. Result The vascular grafts of PVA-PU blends showed patent lumina in the 2 and 16 weeks animals, while those of PU showed a patent lumen in 2 weeks animal. PVA-PU graft of 16 weeks showed a fairly clean luminal surface. A light microscopic finding of this graft demonstrated good tissue infiltration through porosity, The animals with vascular patches showed patent arteries in both groups except 2 weeks animal. Scanning electron microscopy of the luminal surfaces of G-PU patches in 4 and 6 weeks animals showed endothelial cell covering with microvilli. PU patches showed qualitatively less endothelial cell covering. Conclusion: In conclusion, PVA-PU and G-PU blends can be a promising blood contacting surfaces for application in a synthetic vascualr graft. However, further animal study is needed to determine the real long-term effects of these methods of surface modifications.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.149-159
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• 2008

Background: With increasing coronary bypass and peripheral vascular surgeries, the demand for homologous vascular or synthetic conduits has continued to grow, but wide-spread application has been limited by dismal patency rates. Although cryopreserved allograft valves may provide a suitable alternative, current viability or patency of implanted allograft vascular conduits has been unsatisfactory. Material and Method: We serially analyzed the outcomes of canine femoral artery and saphenous vein allograft implants after storage in either $4^{\circ}C\;or\;-170^{\circ}C$. Result: There were no differences in graft flow rate (patency) (p=0.264), rate of thrombosis (p=0.264), presence of endothelium (p=0.587), or immunohistochemical staining for thrombomodulin (p=0.657) were detected between grafts stored in $4^{\circ}C\;and\;-170^{\circ}C$. Greater flow occurred in the arterial grafts versus the venous grafts (p=0.030), irrespective of the preservation method, with a significantly lower incidence of thrombosis (p=0.030) in arterial allografts. There was a correlation coefficient of -0.654 between thrombosis and positive immunohistochemical staining for thrombomodulin (p=0.006) and a correlation coefficient of 0.520 (p=0.0049) between the endothelial presence and positive immunohistochemical staining for thrombomodulin. The relationship between the presence of endothelium and thrombomodulin expression failed to show any correlation within the first 2 weeks (p=0.306). However, a strong correlation was seen after 1 month (p=0.0008). Conclusion: Tissue storage in either $4^{\circ}C\;or\;-170^{\circ}C$ in 10% DMSO/RPMI-1640 preservation solution preserved grafts equally well. In terms of thrombosis and graft patency, arterial grafts were superior to venous grafts. Considering the poor correlation between thrombomodulin expression and the presence of an endothelium in the implanted graft within the first two weeks, grafts in this period would not be thromboresistant.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.949-965
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• 1996

The main goal of periodontal therapy is to restore the lost periodontal tissue and establish the attachment appratus. Current acceptable therapeutic techniques are included : removal of diseased soft tissue, demineralization of exposed root surface, using the barrier membrane for preventing the downgrowth of gingival epithelial cell, insertion of graft materials as a scaffolding action, and biological mediators for promoting the cell activity. The latest concept one among them has been studied which based on the knowledge of cellular biology of destructed tissue. Platelet-derived growth factor(PDGF) is one of the polypeptide growth factor which have been reported as a biological mediator to regulate activities of wound healing progress including cell proliferation, migration, and metabolism. The purposes of this study is to evaluate the influences of the PDGF as biological mediator to periodontal ligament and bone marrow cell. Both right and left maxillary first molar were extracted from rat which had treated with 0.4% ${\beta}-Aminopropionitril$ for 5 days, and feeded until designed date to sacrifice under anesthesisa. Periodontal ligament were removed from the extracted socket of the rat, and cultured with Dulbecco's Modified Essential Medium(DMEM) contained with 10% Fetal Bovine Serum, 100U/ml penicillin, $100{\mu}g/ml$ streptomycin, $0.5{\mu}g/ml$ amphotericin-B. Bone marrow cell were culture from bone marrow suspension with which washed out from femur with same medium. The study was performed to evaluate the effect of PDGF to periodontal ligament and bone cell, cell proliferation rate, total protein synthesis, and alkaline phosphatase activity of rat periodontal ligament(PDL) cell and bone stromal(RBS) cell in vitro. The effects of growth factors on both cells were measured at 3, 5th day after cell culture with (control group) or without growth factors(experimental group). The results were as follows: 1. The tendency of cell proliferation under the influence of PDGF showed more rapid proliferation pattern than control at 3 and 5 days after inoculation. 2. The activity of Alkaline phosphatase revealed 14, 80% increased respectively at 3, 5 days culture than control group. Measurements of ALPase levels indicated that PDL cells had significantly higher activity when compared with that of co-culture groups and GF only(P<0.05). And, ALPase activity in 10 days was higher than that of 7 days(P<0.05). 3. The tendency of formation of the mineralized nodule were observed dose-depend pattern of PDL cells. There was statistically significant difference among group l(PDL 100%), 2(PDL 70%:GF 30%), and 3(PDL 50%:GF 50%)(P<0.01). But, there was no difference among group 3, 4(PDL 30%:GF 70%), and 5(GF 100%). 4. Also, the number of nodule was greater in co-culture of PDL 70% and GF 30% than in culture of PDL 70%(P<0.05). From the above results, it is assumed that the PDGF on PDL cells and RMB cell culture. GF stimulates the cell growth, which is not that of PDL cells but GF. And, the activity of ALPase depends on the ratio of PDL cells, and ALPase may relate to the initial phase of nodule formation. Also, it is thought that the calcified nodule formation principally depends on PDL cells, is inhibited by GF, and affected by cell density. In conclusion, platelet-derived growth factor can promote rapid osteogenesis during early stage of periodontal tissue regeneration.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.130-137
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• 2021

Purpose: The various suture techniques can be utilized in order to maximize the keratinized tissue healing around dental implants. The aim of this study is to compare the soft tissue healing pattern between two different suture techniques after implant placement. Materials and Methods: 15 patients with 18 implants were enrolled in this study. Simple implant placement without any additional bone graft was performed. Two different suture techniques were used to tug in the mobilized flap near the healing abutment after paramarginal flap design. Digital intraoral scan was performed at baseline, post-operation, stitch out, and 3 months after operation. The scan data were aligned using multiple points such as cusp, fossa of adjacent teeth, and/or healing abutment. After subtracting scan data at baseline with other time-point results, closed space indicating volume increment of peri-implant mucosa was selected. The volume of the close space was measured in mm³. The volume between two suture techniques at three time-points was compared using nonparametric rank-based analysis. Results: Healing was uneventful in both groups. Both suture technique groups showed increased soft tissue volume immediately after surgery. The amount of volume increment significantly decreased after 3 months (P < 0.001). Flap folding suture group showed higher median of volume increment than interrupted suture group after 3 months without any statistical significance (P > 0.05). Conclusion: After paramarginal flap reflection, the raised flaps stabilized by flap folding suture showed relatively higher volume maintenance after 3-month healing period. However, further studies are warranted.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.303-320
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• 1994

Current acceptable methods For promotin gperiodontal regeneration are base on removal of diseased soft tissue, root treatment, guided tissue regeneration, inteoduction of new graft materials and biological mediators. Platelet-derived growth factor(PDGF) is one of polypeptide growth factor. PDGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purposes of this study is to evaluate the effects of PDGF-AA, BB on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were prepared from the first premolar tooth extracted for the orthodontic treatment and were cultured in DMEM/10% FBS at the $37^{\circ}C$, 5% $CO_2$ incubator. Author measured the DNA synthesis, total protein, collagen and noncollagenous protein synthesis and alkaline phosphatase activity according to the concentration of PDGF-AA and BB(0, 0.1, 1, 10, 100ng/ml). The results were as follows : The DNA synthetic activity was increased dose dependently by PDGF-AA and BB. The maximum mitogenic effect was at the 100ng/ml of PDGF-AA and 10ng/ml of PDGF-BB. The total protein, collagen and noncollagen systhesis was increased dose dependently by PDGF-AA and BB. The % of collagen was slightly decresed according to the concentration of PDGF-AA and BB. The effect of PDGF-AA and BB were not specific for collagen synthesis since it also increased noncollagenous protein synthesis. The effect of PDGF-AA and BB on alkaline phosphatase activity did not show any significant, meanwhile the alkaline phosphatase activity of 14 days group showed significnat increase. In conclusion, PDGF-AA and BB may have important roles in stimulation of DNA synthesis in human periodontal ligament cells, which means an increase in collagen-synthesizing cells, and may be useful for clinical application in periodontal regenerative procedures.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.237-246
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• 2008

Purpose: If bone grafts and guided tissue regeneration are effective individually in treating osseous defects, then the questionis, what would happen when they are combined. Bone grafts using Calcium Carbonate(Biocoral) and Guided Tissue Regeneration using Calcium Sulfate(CALMATRIX) will maximize their advantages and show the best clinical results in intrabony defects. This study was to compare the effects of a combination of CS and CC with control treated only with modified widman flap in a periodontal repair of intrabony defects. Materials and Methods: 30 patients with chronic periodontitis were used in this study. 10 patients were treated with a combination of CS and CC as the experimental group II and another 10 patients were treated with CC as the experimental group I, and the remaining 10 patients, the control group were treated only with modified widman flap. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded 6 months later. Results: The probing depth changes were $3.30{\pm}1.34\;mm$ in the control group, $4.2{\pm}1.55\;mm$ in the experimental group I(CC) and $5.00{\pm}1.33\;mm$ in the experimental group II(CS+CC). They all showed a significant decrease 6 months after surgery(p<0.01). There was a significant difference(p<0.05) between the control and experimental group. However there were no significant difference(p<0.05) between the experimental group I and II. The gingival recession changes w $-1.30{\pm}1.25\;mm$ in the control group, This is a significant difference(p<0.01). However, there was a $-0.50{\pm}0.53\;mm$ change in the experimental group I(CC) and $-0.60{\pm}0.97\;mm$ in the experimental group II(CS+CC). In addition, in terms of gingival recession, there was a no significance difference(p<0.05) among the groups. The clinical attachment level changes were $2.00{\pm}1.33\;mm$ in the control group, $3.60{\pm}1.58\;mm$ in the experimental group I(CC) and $4.40{\pm}1.17\;mm$ in the experimental group II(CS+CC). They all showed a significant decrease 6 months after surgery(p<0.01). There was a significant difference(p<0.05) between the control and experimental group. However there was a no significance difference(p<0.05) between the experimental group I and II. The bone probing depth changes were $0.60{\pm}0.52\;mm$ in the control group, $3.20{\pm}1.48\;mm$ in the experimental group I(CC) and $4.60{\pm}1.43\;mm$ in the experimental group II(CS+CC). All of them showed a significant decrease 6 months after surgery(p<0.01), there was a significance difference(p<0.05) among the groups. Conclusion: Treatment using a combination of CS and CC have a potential to improve periodontal parameters in intrabony defects and More efficient clinical results can be expected in intrabony defects less than 2 walls grafted with CS and CC.