• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.317-333
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• 1996

The main goal of periodontal regeneration is to be achieved by epithelial exclusion, periodontal ligament cell activation or alveolar bone regeneration. The purpose of this study was to investigate on the physico- chemical and biological characteristics of biodegradable chitosan beads. Chitosan beads were fabricated by ionic gelation with sodium tripolyphosphate and they had the size in 300um diameter. As therapeutic agent, flurbiprofen was incorporated into the beads by 10, 20% loading contents. The release of drugs from the chitosan beads was measured in vitro. Also, biological activity tests of flurbiprofen loaded chitosan beads including cytotoxicity test, ihhibition of $IL-1{\beta}$ production, suppression to $PGE_2$ production, collagenase inhibition test, the ability of total protein synthesis, and tissue response were evaluated. The amount of flurbiprofen released from chitosan was 33-50% during 7 days. Minimal cytotoxicity was observed in chitosan beads. Flurbiprofen released from chitosan beads significantly suppressed the $IL-1{\beta}$ production of monocyte, $PGE_2$ production and markedly inhibited collagenase activity. Meanwhile, flurbiprofen released from this system showed increased ability for protein synthesis. Throughout 4 -week implantation period, no significant inflammatory cell infiltrated around chitosan bead and also fibroblast like cell types at the beads - tissue interface were revealed with gradual degradation of implanted chitosan beads. From these results, it was suggested that flurbiprofen loaded chitosan beads can be effectively useful for biocompatible local delivery system in periodontal regeneration.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.157-157
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• 2017

Titanium and its alloys that have a good biocompatibility, corrosion resistance, and mechanical properties such as hardness and wear resistance are widely used in dental and orthopedic implant applications. They can directly connect to bone. However, they do not form a chemical bond with bone tissue. Plasma electrolytic oxidation (PEO) that combines the high voltage spark and electrochemical oxidation is a novel method to form ceramic coatings on light metals such as titanium and its alloys. This is an excellent reproducibility and economical, because the size and shape control of the nano-structure is relatively easy. Silicon (Si), manganese (Mn), and magnesium (Mg) has a useful to bone. Particularly, Si has been found to be essential for normal bone, cartilage growth and development. Manganese influences regulation of bone remodeling because its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. Insufficience of Mn in human body is probably contributing cause of osteoporosis. Pre-studies have shown that Mg plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. The objective of this work was to study nucleation and growth of bone-like apatite formation on Ti-6Al-4V in solution containing Mn, Mg, and Si ions after plasma electrolytic oxidation. Anodized alloys was prepared at 270V~300V voltages. And bone-like apatite formation was carried out in SBF solution for 1, 3, 5, and 7 days. The morphologies of PEO-treated Ti-6Al-4V alloy in containing Mn, Mg, and Si ions were examined by FE-SEM, EDS, and XRD.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.148-154
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• 2011

Purpose: As the Korean life style is becoming westernized at a rapid pace, the rate of breast cancer is growing at the same time. So, the case of breast reconstruction after mastectomy increases, too. Points of breast reconstruction are symmetry, scar, size, and shape. Especially symmetry and scar are more important than others for Korean. This study is aimed to identify the method of breast reconstruction that accomplished the best results in terms of symmetry and scar. Methods: A total 15 patients were operated on from March of 2005 to July of 2009. The 5 patients were reconstructed by mammoreduction method after periareolar incision, the 7 patients were reconstructed by pectoralismajor transfer with implant after periareolar incision, and 3 patient were reconstructed by both breast augmentation. Results: Follow up period was 20.2 months on average and no complications such as breast deformity were observed. In symmetry of breast, the satisfaction score of periareolar approach is 4.4 and the satisfaction score of other approaches are 4.2 (p>0.05). But in scar of breast, the satisfaction score of periareolar approach is 4.6 and the satisfaction score of other approaches is 3.4 (p<0.05). Conclusion: In conclusion, Author's method of breast reconstruction after removal of breast cancer through periareolar incision is effective method in patients who care about aesthetic result after mastectomy.

• Archives of Plastic Surgery
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• v.39 no.4
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• pp.323-328
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• 2012

Background Among the various methods for correcting nasal deformity, the composite graft is suitable for the inner and outer reconstruction of the nose in a single stage. In this article, we present our technique for reconstructing the ala and columella using the auricular chondrocutaneous composite graft. Methods From 2004 to 2011, 15 cases of alar and 2 cases of columellar reconstruction employing the chondrocutaneous composite graft were studied, all followed up for 3 to 24 months (average, 13.5 months). All of the patients were reviewed retrospectively for the demographics, graft size, selection of the donor site and outcomes including morbidity and complications. Results The reasons for the deformity were burn scar (n=7), traumatic scar (n=4), smallpox scar (n=4), basal cell carcinoma defect (n=1), and scar contracture (n=1) from implant induced infection. In 5 cases of nostril stricture and 6 cases of alar defect and notching, composite grafts from the helix were used ($8.9{\times}12.5$ mm). In 4 cases of retracted ala, grafts from the posterior surface of the concha were matched ($5{\times}15$ mm). For the reconstruction of the columella, we harvested the graft from the posterior scapha ($9{\times}13.5$ mm). Except one case with partial necrosis and delayed healing due to smoking, the grafts were successful in all of the cases and there was no deformity of the donor site. Conclusions An alar and columellar defect can be reconstructed successfully with a relatively large composite graft without donor site morbidity. The selection of the donor site should be individualized according to the 3-dimensional configuration of the defect.

• Journal of Sensor Science and Technology
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• v.11 no.3
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• pp.171-182
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• 2002

The differential electromagnetic transducer for IME(implantable middle ear) system, which have two small permanent magnets glued with the same pole facing each other in the coil, has high vibration efficiency and does not influenced by external magnetic field. In this paper, using finite element method, highly efficient structure of the transducer was proposed and vibration force of the transducer was calculated by electromagnetic theory. And the necessary vibration force of transducer to transmit the sound signal to inner ear when the transducer is attached at stapes was calculated and the design parameters of the transducer were investigated. Using the parameters, the differential electromagnetic transducer was manufactured in small size to implant in confined human middle ear. And it was examined by unloaded and loaded vibration experiment using temporal bone sampled from cadaver.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.191-203
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• 1997

Recently, alteration on chemical treatment on the root and removal of pathologic bacteria, which is the main reason for periodontal disease, by complete removal of infected cementum layer was been emphasied In this study, teeth extracted due to periodontal disease were root planed using periodontal curette and roto bur. Then they were treated with different concentration of Tetracycline HCI at different time. The state of root surface and change in the pre and post treatment was observed. The results were as follows. 1. The group treatment with periodontal curette and saline showed remaining plaque, debris and irregular surface and no dentianl tubule orifice could be seen. 2. The group treatment with periodontal curette and tetracycline HCI showed process compoed with decacified material and there was concanity seemed to be a lacunae of cementocyte. 3. The group treatment with roto bur and saline, there was no remaning plaque and partial dentinal tubule orifice could be seen but smear layer covering them.4. The group treatment with roto bur and tetracycline HCI showed various shape and size dentinal tubule orifice could be seen. From the results, roto bur showed cleaner surfaces than treatment with periodontal curette. But still smear layer existed. Thus for regeneration of periodontal tissue, chemical treatment using tetracycline HCI should follow roto bur treatment. And it is considered that the treatment time is more important than the concentration of tetracycline HCl.

• Journal of Periodontal and Implant Science
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• v.43 no.2
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• pp.79-86
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• 2013

Purpose: The purpose of study was to compare glycemic control using glycated hemoglobin levels ($HbA_{1c}$) in diabetic patients with chronic generalized periodontitis (CGP) undergoing scaling and root planing (SRP) with and without systemic doxycycline. Methods: Fifty subjects with type 2 diabetes mellitus ($T_2DM$) and CGP receiving antidiabetic therapy were selected for study. The selected subjects were randomly assigned to two groups (test group [TG] and control group [CG]) comprising 25 patients each. The TG received SRP followed by systemic doxycycline. The CG received treatment with SRP only. The periodontal parameters were recorded at baseline (day zero), and every 1 month for 4 months and included probing depth, clinical attachment level, plaque index, gingival index, and $HbA_{1c}$ level were recorded at baseline (day zero) and at the end of 4 months. Results: A statistically significant effect was demonstrated for the periodontal parameters for both the TG and CG. $HbA_{1c}$ values did not show a statistically significant difference in the treatment group as compared to the CG. Conclusions: The authors concluded that nonsurgical periodontal therapy improved glycemic control in patients with $T_2DM$ in both groups, but no statistical difference was observed with adjunctive systemic doxycycline therapy. A further study with a larger sample size is required.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.273-298
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• 2008

Purpose: The aim of this review is to introduce a novel bone-graft material for hard-tissue regeneration based on the calcium phosphate glass(CPG). Materials and Methods: CPG was synthesized by melting and subsequent quenching process in the system of CaO-$CaF_2-P_2O_5$-MgO-ZnO having a much lower Ca/P ratio than that of conventional calcium phosphates such as HA or TCP. The biodegradability and bioactivity were performed. Effects on the proliferation, calcification and mineralization of osteoblast-like cells were examined in vitro. Influence in new bone and cementum formations was investigated in vivo using calvarial defects of Sprague-Dawley rats as well as 1-wall intrabony defect of beagle dogs. The application to the tissue-engineered macroporous scaffold and in vitro and in vivo tests was explored. Results: The extent of dissolution decreased with increasing Ca/P ratio. Exposure to either simulated body fluid or fetal bovine serum caused precipitation on the surface. The calcification and mineralization of osteoblast-like cells were enhanced by CPG. CPG promoted new bone and cementum formation in the calvarial defect of Sprague-Dawley rats after 8 weeks. The macroporous scaffolds can be fabricated with $500{\sim}800{\mu}m$ of pore size and a three-dimensionally interconnected open pore system. The stem cells were seeded continuously proliferated in CPG scaffold. Extracellular matrix and the osteocalcin were observed at the $2^{nd}$ days and $4^{th}$ week. A significant difference in new bone and cementum formations was observed in vivo (p<0.05). Conclusion: The novel calcium phosphate glass may play an integral role as potential biomaterial for regeneration of new bone and cementum.

• Imaging Science in Dentistry
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• v.46 no.2
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• pp.127-131
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• 2016

Purpose: This study was performed to compare the condylar position in patients with temporomandibular joint disorders (TMDs) and a normal group by using cone-beam computed tomography (CBCT). Materials and Methods: In the TMD group, 25 patients (5 men and 20 women) were randomly selected among the ones suffering from TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The control group consisted of 25 patients (8 men and 17 women) with normal temporomandibular joints (TMJs) who were referred to the radiology department in order to undergo CBCT scanning for implant treatment in the posterior maxilla. Linear measurements from the superior, anterior, and posterior joint spaces between the condyle and glenoid fossa were made through defined landmarks in the sagittal view. The inclination of articular eminence was also determined. Results: The mean anterior joint space was 2.3 mm in the normal group and 2.8 mm in the TMD group, respectively. The results showed that there was a significant correlation between the superior and posterior joint spaces in both the normal and TMD groups, but it was only in the TMD group that the correlation coefficient among the dimensions of anterior and superior spaces was significant. There was a significant correlation between the inclination of articular eminence and the size of the superior and posterior spaces in the normal group. Conclusion: The average dimension of the anterior joint space was different between the two groups. CBCT could be considered a useful diagnostic imaging modality for TMD patients.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.422-441
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• 1993

The purpose of this study was to compare effects of the bioceramics on healing processes of the alveolar bone defects in dogs. Five adult dogs aged 1 to 2 years were used in this study. Experimental alveolar bone defects were created surgically with a #1/2 round bur at the furcation area of the buccal surface of the mandibular 3rd, 4th premolars and 1st molar. Fifteen experimental alveolar bone defects were devided into three groups according to the type of graft materials. The groups were as follows : 1) flap operation with dense hydroxyapatite( DHA group ) 2) flap operation with porous hydroxyapatite( PHA group ) 3) flap operation with natural coral ( NC group ) At 1, 2, 4, 6, and 12 weeks, dogs were serially sacrificed and specimens were prepared with Hematoxylin-Eosin stain and Mallory stain for light microscopic evaluation. The results of this study were as follows : 1. In every group, inflammatory cell infiltrations were seen at 1st weeks due to surgical trauma, however inflammatory response owing to graft materials were not seen. 2. In every group, the appearance of connective tissue around graft materials was loosely formed at the initial stages, however the connective tissue was densely formed at 2 weeks. 3. The presence of osteocytes were observed at 2 weeks in the natural coral group, however the osteocytes were appeared at 6weeks in the dense hydroxyapatite group. 4. A new bone was formed from the base and walls of the defect and gradually expanded toward the graft materials. 5. A resorption of the natural coral occurred irregularly at the periphery of the material, therefore the size and shape of the natural coral were reduced at 6 weeks. 6. At 12 weeks, the porous hydroxyapatite and natural coral were surrounded by newly formed bone most completely, however dense hydroxyapatite was surrounded by newly formed bone in part.