• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.28.1-28.16
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• 2018

This study investigated the latest findings and notions regarding 'triple antibiotic paste' (TAP) and its applications in dentistry, particularly endodontics. TAP is a combination of 3 antibiotics, ciprofloxacin, metronidazole, and minocycline. Despite the problems and pitfalls research pertaining to this paste has unveiled, it has been vastly used in endodontic treatments. The paste's applications vary, from vital pulp therapy to the recently introduced regeneration and revascularisation protocol. Studies have shown that the paste can eliminate the root canal microorganisms and prepare an appropriate matrix for further treatments. This combination is able to remove diverse groups of obligate and facultative gram-positive and gram-negative bacteria, providing an environment for healing. In regeneration protocol cases, this allows the development, disinfection, and possible sterilization of the root canal system, so that new tissue can infiltrate and grow into the radicular area. Moreover, TAP is capable of creating a discipline in which other wanted and needed treatments can be successfully performed. In conclusion, TAP, as an antibacterial intracanal medication, has diverse uses. Nevertheless, despite its positive effects, the paste has shown drawbacks. Further research concerning the combined paste and other intracanal medications to control microbiota is a must.

• Implantology
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• v.18 no.2
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• pp.120-138
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• 2014

Purpose: The purpose of this study was to review the outcomes of a series of studies on tissue regeneration conducted in multiple institutions including the Department of Periodontology, College of Dentistry, Yonsei University. Materials and Methods: Studies were performed divided into the following three subjects; 1) Development of three-dimensional nano-hydroxyapatite (n-HA) scaffold for facilitating drug release and cell adhesion. 2) Synergistic effects of bone marrow-derived mesenchymal stem cells (BMMSC) application simultaneously with platelet-rich plasma (PRP) on HA scaffolds. 3) The efficacy of silk scaffolds coated with n-HA. Also, all results were analyzed by subjects. Results: Hollow hydroxyapatite spherical granules were found to be a useful tool for the drug release and avidin-biotin binding system for cell attachment. Also, BMMSC simultaneously with PRP applied in an animal bone defect model was seen to be more synergistic than in the control group. But, the efficacy of periodontal ligament cells and dental pulp cells with silk scaffolds could not be confirmed in the initial phase of bone healing. Conclusion: The ideal combination of three elements of tissue engineering-scaffolds, cells and signaling molecules could be substantiated due to further investigations with the potentials and limitations of the suggested list of studies.

• Journal of Biosystems Engineering
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• v.38 no.2
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• pp.113-120
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• 2013

Purpose: Stem cells provide new opportunities in the regenerative medicine for human or animal tissue regeneration. In this study, we report an efficient method for the modulating behaviors of electro-active stem cells by micro-electric current stimulation (mES) without using chemical agents, such as serum or induction chemicals. Methods: Dental pulp stem cells (DPSCs) were cultured on the tissue culture dish in the mES system. To find a suitable mES condition to promote the DPSC functions, the response surface analysis was used. Results: We found that a working micro-current of 38 ${\mu}A$ showed higher DPSC proliferation compared with other working conditions. The mES altered the expressions of intracellular and extracellular proteins compared to those in unstimulated cells. The mES with 38 ${\mu}A$ significantly increased osteogenesis of DPSCs compared with ones without mES. Conclusions: Our findings indicate that mES may induce DPSC proliferation and differentiation, resulting in applying to DPSCs-based human or animal tissue regeneration.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.286-298
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• 1999

The endodontic-periodontic combined lesions have been difficult to get correct diagnosis and predictable treatment. This study was to make the experimental endodontic-periodontic combined defects in dogs for the study of the periodontal regeneration and to evaluate the efficacy of the enamel matrix protein and e-PTFE membrane in the experimental endodontic-periodontic combined defects. 5 mongrel dogs were used. The pulp chambers were opened and the plaque was inserted into the chambers to induce the periapical lesions on the mandibular second, third and fourth premolars of the dogs. 1 month later, the root canal treatments were done with gutta perch a and ZOE sealer. On the day of surgery, the periapical defects were standardized by trephine bur. The buccal dehiscence defects were made by the dental bur and bone chisels. The apicoectomy with retrofilling was done. The prepared roots were randomly selected for test and control groups. In the experimental groups, the enamel matrix derivative and e-PTFE membrane were used. Nothing was placed on the control group. Fluroscent labelling was used to evaluate the bone formation. After 4 and 12 weeks, the dogs were sacrificed and undecalcified sections were prepared and stained with toluidine blue. Those histologic sections were examined by fluorescent microscopy and light microscopy. The results were as follows. 1. In the control group, new bone was formed in the periapical defects and scarcely in the buccal dehiscence defects. New cementum was not detected at 4 and 12 weeks. 2. In the experimental groups, new bone, new cementum and periodontal ligament were found in the periapical and buccal dehiscence defects. The relative amount and the quality of the new bone, new cementum and periodontal ligament tissue that had formed on the experimental groups were superior to those of the control group. 3. The current observation implicated that e-PTFE membrane and enamel matrix protein could be the effective tools for the guided tissue regeneration of the endo-perio combined defects.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.44-50
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• 2011

An immature tooth with infected pulp has numerous potential complications. Conventional apexification with calcium hydroxide has several disadvantages, including susceptibility to tooth fracture. This method does not promote continual root development. Pulp revascularization of a necrotic, immature permanent tooth will allow further development of the root and dentinal structure. Disinfection of the root canal system is a prerequisite for pulp revascularization and tissue regeneration. A combination of antibiotic drugs (ciprofloxacin, metronidazole, and minocycline) is effective for disinfection of necrotic pulp, and has been used successfully in regenerative endodontic treatment. These case reports involve the treatment of 3 immature permanent teeth with necrotic pulp using a 3-Mix paste and mineral trioxide aggregate. All cases showed the notable apical maturation with closure of the apex and increased thickness of dentinal walls. This approach suggests a paradigm shift in treating endodontically involved immature permanent teeth from the traditional apexification with calcium hydroxide to the conservative approach by providing a favorable environment for tissue regeneration.

• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.5-12
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• 2010

The purpose of this study was to evaluate the pulp tissue reaction to direct pulp capping of mechanically exposed beagle dogs' pulp with several capping materials. A total of 36 teeth of 2 healthy beagle dongs were used. The mechanically exposed pulps were capped with one of the followings: (1) Mineral Trioxide Aggregate (MTA: $ProRoot^{(R)}$ MTA. Dentsply, Tulsa, USA), (2) Clearfil SE Bond (Dentin adhesive system: Kuraray, Osaka, Japan), (3) Ultra-Blend (Photo-polymerized Calcium hydroxide: Ultradent, South Jordan, USA), (4) Dycal (Quick setting Calcium hydroxide: LD Caulk Co., Milford, USA) at 7, 30, and 90 days before sacrificing. The cavities were restored with Z350 flowable composite resin (3M ESPE, St. Paul. MN, USA). After the beagle dogs were sacrificed, the extracted teeth were fixed, decalcified, prepared for histological examination and stained with HE stain. The pulpal tissue responses to direct pulp capping materials were assessed. In MTA calcium hydroxide, and photo-polymerized calcium hydroxide groups, initial mild inflammatory cell infiltration, newly formed odontoblast-like cell layer and hard tissue bridge formation were observed. Compared with dentin adhesive system, these materials were biocompatible and good for pulp tissue regeneration. In dentin adhesive system group, severe inflammatory cell infiltration, pulp tissue degeneration and pulp tissue necrosis were observed. It seemed evident that application of dentin adhesive system in direct pulp capping of beagle dog teeth cannot lead to acceptable repair of the pulp tissue with dentine bridge formation.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.171-171
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• 2004

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.89-112
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• 2002

The earliest reports of the use of electrical energy to directly stimulate bone healing seem to be in 1853 from England, the techniques involved the introduction of direct current into the non-united fracture site percutaneously via metallic needles, with subsequent healing of the defect. One endpoint of the periodontal therapy is to generate structure lost by periodontal diseases. Several procedural advances may support regeneration of attachment, however, regeneration of alveolar bone does not occur consistently. Therefore, factors which stimulate bone repair are areas for research in periodontal reconstructive therapy. Effects of cytokines or growth factors on bone repair are examples of such areas. Another one is electrical current which occurs in bone naturally, so that such bone may be particularly susceptible to electrical therapy. The purposes of this study were to observe the effects of electrical stimulation on the normal periodontium, to determine whether the electricity is the useful means for periodontal regeneration or not. Forty rats weighted about 100 gram were used and divided into 4 groups, the first group, there was no electrical stimulation with the connection of electrodes only. In the second group, there was stimulated by the 10 mA during 10 minutes per a day, in the third group was stimulated by the 25 mA , and the fourth by the 50 mA. At 3, 5, 10 and 15 days post-appliance , two rats in each group were serially sacrificed. and the maxillae and the mandible processed to paraffin, and the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows : 1. There was the distinct reversal line on the lingual alveolar crest, whereas a little changes in the labial alveolarcrest to the duration and amount of currents. 2. In 50 mA group, the cells were highly concentrated at the apex of anterior teeth, and was observed the necrotic tissue. In posterior root apex, the hypercementosis was appeared, and newly formed cementum layer has been increased continuously with the time. 3. The periodontal ligament fiber and Sharpey's fiber were arranged in order, and the bone trabeculae were increased as the experiment proceeded by, relatively the bone marrows were decreased. 4. In the pulp tissue, the blood vessels were increased with blood congestion in the experimetal specimens remarkably, and the dentinal tubules were obstructed . 5. The osteoblasts in alveolar bone proper had been showed highly activity, and also observed the formation of bone trabeculea. In the conclusion, it was suggested that the electrical stimulation has influence on the periodontium and the pulp tissue. However, there might be the injurious effects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.2
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• pp.55-62
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• 2013

Bone tissue engineering is one of the important therapeutic approaches to the regeneration of bones in the entire field of regeneration medicine. Mesenchymal stem cells (MSCs) are actively discussed as material for bone tissue engineering due to their ability to differentiate into autologous bone. MSCs are able to differentiate into different lineages: osteo/odontogenic, adipogenic, and neurogenic. The tissue of origin for MSCs defines them as bone marrow-derived stem cells, adipose tissue-derived stem cells, and, among many others, dental stem cells. According to the tissue of origin, DSCs are further stratified into dental pulp stem cells, periodontal ligament stem cells, stem cells from apical papilla, stem cells from human exfoliated deciduous teeth, dental follicle precursor cells, and dental papilla cells. There are numerous in vitro/in vivo reports suggesting successful mineralization potential or osteo/odontogenic ability of MSCs. Still, there is further need for the optimization of MSCs-based tissue engineering methods, and the introduction of genes related to osteo/odontogenic differentiation into MSCs might aid in the process. In this review, articles that reported enhanced osteo/odontogenic differentiation with gene introduction into MSCs will be discussed to provide a background for successful bone tissue engineering using MSCs with artificially introduced genes.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.35-45
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• 1983

This study was undertaken to evaluate the pulpal responses to the intermediate restorative materials such as Zinc phosphate cement, Polycarboxylate cement, IRM (zinc oxide eugenol cement), Dycal, Life, Cresatin, and Fluoride in caivties which were cut with high speed instrument. 5 dogs were used as experimental animals and devided into 8 groups. The intervals of observaobservation ranged 3 days, 1, 3, 4, 8 weeks after experiment respectively. The specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All slides were stained with hemtoxylin-eosin and examined histopathologically. The results were as follows: 1. In control group, severe vacuolar degeneration and atrophy of odontoblasts were seen in 3 days, hemorrhage and congestion continued until 8 weeks. Necrosis of odontoblastic layer was seen in zinc phosphate cement group and polycarboxylate cement group. 2. In dycal group, vacuolar degeneration and atrophy of odontoblast were not seen. but in Life group, these were seen in 3 days and partially continued until 3 weeks. In 4 weeks, regeneration of odontoblast was occured. 3. In Crcsatin group, there was no pathosis except odontoblastic displacement. In Fluoride group, vacuolar degeneration of odontoblast was seen and soon disappeared. As compared with control group, pathological change of the pulp tissue in experimental group were decreased after amalgam restoration.