• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.556-561
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• 1997

Intentional replantation of the posterior teeth has been performed as a last resort except extraction when it is impossible to perform the conventional endodontic or surgical endodontic treatment. Many studies have done with the prognosis, and root resorption, of which the responsibility might have been injury of periodontal ligament and remaining periodontal lesion, proved to be major cause of failure. Intentional replantation, however, can exclude anatomic difficulty, risk of nerve injury, and maxillary sinus trauma that surgical access can raise, especially in posterior teeth, and it is reported that success rate is not less than surgical endodontics, independent of replantation of traumatically avulsed teeth. The success of intentional replantation can be evaluated with, clinically, reduction of pocket depth, pain and mobility(physical mobility), and, radiographically, hard tissue formation, reduction of periapical radiolucency. In this case report, for the maxillary left first bicuspid with dens evaginatus that had periapical lesion, painfulness, mobility and showed no reduction of mobility after even extirpation and a number of irrigation, extraction followed by extraoral root filling with calcium hydroxide and replantation was performed. Based on many studies, it is concluded that hard tissue formation capacity of calcium hydroxide, preceded extirpation before extraction, and careful extraction without injuring periodontal ligament affected successful results of this case.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.87-94
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• 2001

The present study was performed to investigate the effect of $HTR^{(R)}$ (Hard Tissue Replacement) on osteogenesis in the mandibular bone defects. Eight adult male white rabbits weighing 2.5 to 3.0kg were used. Four bone defects (8mm in diameter and 4mm in depth) were made at the both mandibular body. In the control group, the right mesial bone defect was filled with blood clot and spontaneously healed. In the DFDB group, the right distal bone defect was filled with xenogenic demineralized freeze-dried bone. In the $HTR^{(R)}$ group, the left mesial bone defect was filled with $HTR^{(R)}$. In the $HTR^{(R)}-membrane$ group, the left distal bone defect was filled with $HTR^{(R)}$ and covered with BioMesh membrane. The rabbits were sacrified at 2,4,6 and 9 weeks after the operation and microscopic examination was performed. Results obtained were as follows: In the control and DFDB groups, inflammatory cells and the fibrous connective tissue existed and the bone growth was slower than $HTR^{(R)}$ group by 6 week, and there was intervention of the soft tissue at 9 week. In the $HTR^{(R)}$ group, bone trabeculi extended between the $HTR^{(R)}$ particles without intervention of inflammatory cells and the connective tissue at 4 and 6 weeks. In addition, extensive osseous ingrowth into the $HTR^{(R)}$ particles was observed at 9 week. Bone formation was more active in the $HTR^{(R)}$ group than the control and DFDB groups. There was not obvious difference in the bone healing rate between the $HTR^{(R)}$ and the $HTR^{(R)}-membrane$ group. These results suggest that the $HTR^{(R)}$ promotes osteogenesis in the bone defects and the $HTR^{(R)}$ group has no difference in comparison with the $HTR^{(R)}-BioMesh^{(R)}$ membrane group in bone healing.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.117-123
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• 2005

The reconstructive modalities for vaginal reconstruction include simple dilatation, skin graft, use of intestinal segments and various methods using flaps. However, skin grafting procedure is the most commonly used technique and the McIndoe procedure is a representative technique among skin grafting procedures. McIndoe procedure is easier, faster and has a lower morbidity compared to other techniques. However the conventional McIndoe procedure has several problems such as incomplete vestibule formation, excessive bleeding during dissection, possibility of recto-vaginal or urethro-vaginal fistula formation, late vaginal contracture and discomfort in wearing hard plastic mold for a long time after operation. To solve these problems, the authors modified the conventional McIndoe procedure in several perspectives. The undeveloped vestibule was incised with X-shaped mucosal incision between the urethral opening and posterior margin of the vestibule and deepened by blunt finger dissection to provide a sufficient diameter & length of the neovagina and to minimize bleeding. A sizable medium thickness split skin graft was harvested and wrapped over a roll gauze-filled condom mold. Applying multiple stab incision on the skin grafted condom mold, it was inserted into the prepared neovaginal canal. Distal margin of the skin graft was secured with tips of the mucosal flaps created by X-shaped vestibular incision to prevent accidental extrusion of the skin grafted mold. During last 15 years, we applied this modification to 20 vaginal agenesis patients and investigated results of the 12 patients who could be followed up serially including hematoma formation and skin graft survival rate, size, depth, presence of late contracture, appearance, comfortness, and hygiene of the neovagina. And they were compared with 8 patients of 20 patients who underwent conventional McIndoe procedures. The modified McIndoe procedure revealed lower complication rate, higher patient satisfaction and better functional results.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.77-83
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• 2012

We investigated the pulpal response to direct pulp capping in rat molar teeth using mineral trioxide aggregate (MTA) and calcium hydroxide (CH). A palatal cavity was prepared in rat maxillary molar teeth. Either MTA or CH was placed on the exposed pulp and all cavities were restored with composite. Rats were sacrificed for histological evaluation after 12 hours and at 2, 7, 14 and 21 days. In both the MTA and CH groups, reparative dentin formation was clearly observed on histology after 14 days. The MTA-capped pulps were found to be mostly free from inflammation, and hard tissue of a tubular consistent barrier was observed. In contrast, in CH-capped teeth, excessive formation of reparative dentin toward residual pulp was evident. The pulpal cell response beneath the reparative dentin layer was examined by immunofluorescence using antibodies against DSP. After 2 days, a few DSP immunopositive cells, most of which showed a cuboidal shape, appeared beneath the predentin layer. At 7 days, DSP-immunopositive cells with columnar odontoblast-like cells were seen beneath the newly formed hard tissues. At 14 and 21 days, DSP was more abundant in the vicinity of the odontoblastic process along the dentinal tubules than in the mineralized reparative dentin. The CH group showed strong expression patterns in terms of DSP immunoreactivity. Our results thus indicate that MTA may be a more effective pulp capping material as it induces the differentiation of odontoblast-like cells and the formation of reparative dentin without the loss of residual pulp functions.

• Animal cells and systems
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• v.13 no.4
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• pp.363-370
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• 2009

Since vitamin $D_3$ is an important regulator of osteoblastic differentiation, a presently-established vitamin $D_3$-entrapped calcium phosphate film (VCPF) was evaluated for hard tissue engineering. The entrapped vitamin $D_3$ more rapidly induced bone nodule formation. To characterize the cellular events leading to regulations including faster differentiation, signal transduction pathways were investigated in osteoblastic MG63 cells at a molecular level. Major signaling pathways for MG63 cell proliferation including phosphatidylinositol-3-kinase, extracellular signal-regulated kinase, c-Jun N-terminal kinase and focal adhesion kinase pathways were markedly down-regulated when cells were cultured on calcium phosphate film (CPF) and VCPF. This agreed with our earlier observations of the immediate delay in proliferation of MG63 cells upon culture on CPF and VCPF. On the other hand, the p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase A (PKA) pathways were significantly up-regulated on both CPF and VCPF. CPF alone could simulate differential behaviors of MG63 cells even in the absence of osteogenic stimulation and entrapment of vitamin $D_3$ within CPF further amplified the signal pathways, resulting in continued promotion of MG63 cell differentiation. Interplay of p38 MAPK and PKA signaling pathways likely is a significant event for the promotion of differentiation and mineralization of MG63 cells.

• 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.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.109-115
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• 2012

Helicobacter pylori is an important factor of chronic gastritis, digestive ulcer, and stomach cancer. CagL, a virulence factor of H. pylori, is well-known as a pilus protein which acts as adhesion to host cell and a component of Type 4 secretion system. In this study, we evaluated the protective response of recombinant CagL protein (rCagL) using Mongolian gerbil animal model for H. pylori infection. The cagL gene was cloned from 26695 H. pylori followed by over-expression and purification of the protein in E. coli. Mongolian gerbils were immunized with rCagL protein mixed with aluminum adjuvant via intramuscular injections once a week during 4 weeks. At a week after the last immunization, the Mongolian gerbils were administrated with H. pylori 7.13 strain into the stomach and sacrificed to measure antibody titer on rCagL by ELISA and bacterial colonization in the stomach, and to examine the histopathological changes and cytokine expression at 6 week after challenge. Antibody titers on recombinant protein were significantly increased from a week after the first immunization. There was no significant change of the number of bacterial colony between control group and immunized group. The relative stomach weight was significantly decreased in immunized group, but the significant change of histopathological assessment was not observed in the stomach. Cytokine expression such as IL-$1{\beta}$ and KC also was not significantly different between control and immunized groups. These results indicate that rCagL could effectively induce the formation of the specific IgG antibodies. However, bacterial colonization and histopathological lesions could not be inhibited by the immunization in the stomach, indicating not enough protection against H. pylori infection. We consider that along with CagL other adequate antigens could be needed stimulating immune response and inducing protective effects against gastric disease, and also a better adjuvant could be considered.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.89-102
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• 1996

The goal of periodontal therapy is to regenerate the loss of periodontal attachment appratus. Current theories suggest the cells of the periodontium have the capacity, when appropriately triggered, to actively participate in restoring connective tissues, including mineralized tissues. This study was performed to define the hard tissue regeneration effect of periodontal ligament(PDL) cells in vitro and the effect of rate of the composition in gingival fibroblasts(GF) on the hard tissue regeneration capacity of PDL cells. For this study, Cell growth rate, alkaline phosphatase(Al.Pase) levels and the ability to produce mineralized nodules in co-culture of PDL cells and GF were examined. The results were as follows : 1. At 7 and 15 days, Cell growth of co-culture of PDL and GF(50 : 50) was greater than that of PDL cells or GF alone(P>0.05). 2. 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 1(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 co-culture of PDL cells and 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.35-42
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• 2006

The developmental process of a tooth is being presented as an important study subject to analyze formation of normal dental arch and tooth. The purpose of this study was to see the formation of tooth from a tooth bud transplanted in a white rat regarding that the jawbone could be used as a new donor site of a trasplant. The first molar of a matured white rat was extracted and the tooth bud of a 13.5 day rat embryo was transplanted. The histological and radiographical results after 4 and 8 weeks respectively are as the following. 1. Calcification in dentin, cementum, pulp and periodontal ligament was formed from the tooth bud transplanted in the alveolar socket. 2. The development of hard and soft tissue was delayed compared to the normal tooth formation and abnormal histologic features such as ankylosis and osteodentin were found. 3. The formed hard tissue did not erupt into the jaw within 8 weeks.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.79-79
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• 2017

Metallic biomaterials have been mainly used for the fabrication of medical devices for the replacement of hard tissue such as artificial hip joints, bone plates, and dental implants. Because they are very reliable on the viewpoint of mechanical performance. This trend is expected to continue. Especially, Ti and Ti alloys are bioinert. So, they do not chemically bond to the bone, whereas they physically bond with bone tissue. For their poor surface biocompatibility, the surface of Ti alloys has to be modified to improve the surface osteoinductivity. Recently, ceramic-like coatings on titanium, produced by plasma electrolytic oxidation (PEO), have been developed with calciumand phosphorus-enriched surfaces. A lso included the influences of coatings, which can accelerate healing and cell integration, as well as improve tribological properties. However, the adhesions of these coatings to the Ti surface need to be improved for clinical use. Particularly Silicon (Si) has been found to be essential for normal bone, cartilage growth and development. This hydroxyapatite, modified with the inclusion of small concentrations of silicon has been demonstrating to improve the osteoblast proliferation and the bone extracellular matrix production. Strontium-containing hydroxyapatite (Sr-HA) was designed as a filling material to improve the biocompatibility of bone cement. In vitro, the presence of strontium in the coating enhances osteoblast activity and differentiation, whereas it inhibits osteoclast production and proliferation. The objective of this work was to study Morphology of bone-like apatite formation on Sr and Si-doped hydroxyapatite surface of Ti-6Al-4V alloy after plasma electrolytic oxidation. Anodized alloys was prepared at 270V~300V voltages with various concentrations of Si and Sr ions. Bone-like apatite formation was carried out in SBF solution. The morphology of PEO, phase and composition of oxide surface of Ti-6Al-4V alloys were examined by FE-SEM, EDS, and XRD.