• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.317-322
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• 1999

Dens invaginatus is a developmental anomaly resulting from an invagination of the enamel organ. The incidence is highest with maxillary permanent lateral incisors. The reported occurrence ranges from 0.04 to 10%. This anomaly may involve the pulp and periapical tissues and cause pulpal inflammation, loss of vitality, apical and lateral periodontitis, periapical abscesses and cysts and stimulate internal resorption. Oehlers describes dens invaginatus as occurrence in three forms. In treating type 3 invaginatus, treatment strategy can be determined by considering the complexity and accessibility of invagination. In this case, showing simple invagination, it could be treated by simple endodontic treament confining to invagination without loss of vitality of tooth. After treatment of the present case, the results were as follows: 1. In type 3 dens invagiantus, if the tooth is vital and there is no evidence of communicating between invagination and pulp, we can save the vitality of the tooth and resolve the lesion by endodontic treament confining to the invagination. 2. In the invagination with opened apex, the closure of apex can be induced by apexification procedure doing this, we can avoid the neccessity of surgical intervention.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.656-669
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• 1998

Hydrogen peroxide at high concentration during walking bleaching may cause damage to the tooth structure and to the surrounding periodontal tissues and may develop external root resorption. Clinically, It is so important to find a method of prevention or minimization of these complications. The efficacy of various chamber-irrigating agents to eliminate residual hydrogen peroxide after walking bleaching was examined and compared with water rinse in this study. Extracted human 46 premolars without any cementoenamel junction defects were treated endodontically and based with IRM to 1 mm below CEJ and totally bleached 3 times for each tooth with 30% hydrogen peroxide and sodium perborate. Upon completion of the 3rd walking bleaching procedure, the cervical portion and pulp chamber of each group of teeth were irrigated with catalase, 70% ethylalcohol, acetone, and distilled water. And then, a radicular hydrogen peroxide penetration was measured with spectrophotometer immediately after each bleaching and following treatment with each chamber-irrigating agents, and the significance of their eliminating efficacy of residual hydrogen peroxide was analyzed by Kruskal-Wallis test. The results were obtained as follows. 1. Cervical root penetration of hydrogen peroxide was increased as the bleaching procedure was repeated(P<.01). 2. The most effective irrigant that removed residual hydrogen peroxide was the catalase, and the least effective one was water rinsing (P<.01).; there was no significant difference between the acetone and ethanol group. 3. The Irrigation with antioxidant enzyme or water-displacement solutions can eliminate residual oxygen radicals from the pulp chamber effectively after walking bleaching. So, these agents can reduce adverse effects such as cervical external resorption and periapical inflammation and prevent residual $O_2$ from impeding composite resin polymerization, thus increase the bonding strength of composite resin. This, in turn reduces microleakage and discoloration of the esthetic restoration, extending its service-life.

• Proceedings of the KACD Conference
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• 2001.05a
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• pp.247-251
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• 2001

;A dental developmental anomaly is defined as an isolated aberration in tooth form, caused by a disturbance or abnormality which occurred during tooth development. There are numerous types of dental anomalies, and a considerable variation in the extent of the defects occurs with each type. Teeth with these anomalies pose unique challenges. Since the defects are not always apparent clinically, they can confuse diagnosticians investigating the etiology of pulpal pathosis. When endodontic treatment is required, the defects often hinder access cavity preparation and canal instrumentation. Treatment planning also becomes more challenging, since the defects can create complicated periodontal problems, and the malformed teeth can be difficult to restore, particularly those weakened by endodontic therapy. Fusion is defined as the joining of two developing tooth germs resulting in a single large tooth structure. The incidence of fusion is < 1% in the Caucasian population, and it is believed that physical force or pressure produces contact of the developing teeth. Clinically and radiographically, a fused tooth usually appears as one large crown with at least partially separated roots and root canals. There may be a vertical groove in the tooth crown delineating the originally separate crowns. Dens invaginatus is a deep surface invagination of the crown or root that is lined by enamel. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisor is the tooth most commonly involved. Studies have revealed an incidence ranging from 0.25% to as high as 10%. The invagination ranges from a slight pitting to an anomaly occupying most of the crown and root. The invagination frequently communicates with the oral cavity, allowing the entry of irritants and microorganism either directly into pulpal tissues or into an area that is deparated from pulpal tissues by only a thin layer of enamel and dentin. This continuous ingress of irritants and the subsequent inflammation usually lead to necrosis of the adjacent pulp tissue and then to periapical or periodontal abscesses. If the invagination extends from the crown to the periradicular tissue and has no communication with the root canal system, the pulp may remain vital. Recommended treatment of fused tooth and dens invaginatus has been reported in the endodontic literature. This case report describes the endodontic treatment of a maxillary laterl incisors having fused crown and dens invaginatus.natus.

• Restorative Dentistry and Endodontics
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• v.31 no.2
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• pp.86-95
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• 2006

The purpose of this clinical study is to assess whether calcium hydroxide as an intracanal medication affects post-treatment pain in teeth especially odontogenic pain which comes from inflammation of the pulp and periradicular tissues when compared with no intracanal medication. From 213 patients who has been treated 237 root canals due to significant pain (moderate-to-severe) we recorded their age, sex, treated tooth, degree of pain, pre-operative states of the tooth. We classified patients into 2 test group; Group 1 (not gain intracanal $Ca(OH)_2$), Group 2 (gain intracanal $Ca(OH)_2$). Through the survey from the patients, we let them write down the occurrence and degree of post-treatment pain in 4hours, 2days, 7days after treatment as none, mild, moderate or severe. The followings were evaluated ; the overall incidence of flare-ups, the overall incidence of post-treatment pain in each group at each time period , the incidence of post-treatment pain in each group at each time period as related to pre-operative states of the teeth These were compared statistically with Chi-square analysis (p < 0.05). Under the condition of this investigation, no difference was observed in the incidence of post-treat-ment pain between the two groups. Therefore, $Ca(OH)_2$ as intracanal medication had no effect on preventing or decreasing the post-treatment pain.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.289-297
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• 2017

Local and general factors have been attributed to root resorption occurred by injuries such as trauma and dental caries that affect periodontal ligament or dental pulp tissue. Pathologic root resorption is different from physiologic root resorption in terms of resorption pattern such as micromorphology of resorption fossae and types of observed cells. Microscopic morphologies and histologic features of physiologic and pathologic root resorption surface of maxillary primary central incisors resulting from trauma and periapical inflammation were observed by scanning electron microscope and light microscope. The morphology of physiologic resorption lacunae was small and oval or circular shape with regularities. The morphology of pathologic resorption lacunae was large and polygonal shape with irregularities compared with the physiologic resorption lacunae. Multinucleated giant cells and mononuclear cells were closely attached to the physiologic and pathologic resorption lacunae, whereas several kinds of mesenchymal cells with numerous inflammatory cells were found in the areas adjacent to the pathologic resorption surface. Compensating cementum formation took place along some of the areas of physiologic and pathologic resorption area resulting from trauma, but could not be observed on pathologic resorption area resulting from periapical inflammation.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.198-210
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• 2010

This study evaluated the safety of an office bleaching gel (RemeWhite, Remedent Inc., Deurle, Belgium) containing 30% hydrogen peroxide. 37 volunteers were received office bleaching with the RemeWhite for 3 times at one visit, total 2 visits. As control group, the same gel in which hydrogen peroxide was not included was applied to 34 volunteers with the same protocol. There was no difference between experimental group and control group using electric pulp test. In the result of gingival inflammation index and tooth sensitivity test, there was mild pain response in experimental group but it disappeared as time went by. Therefore, safety of the office bleaching gel containing 30% hydrogen peroxide was confirmed.

• The korean journal of orthodontics
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• v.51 no.3
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• pp.199-216
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• 2021

Objective: The aim of this systematic review was to evaluate the complications and side effects associated with the clinical use of orthodontic miniscrews by systematically reviewing the best available evidence. Methods: A survey of articles published up to March 2020 investigating the complications associated with miniscrew insertion, in both the maxilla and mandible, was performed using 7 electronic databases. Clinical studies, case reports, and case series reporting complications associated with the use of orthodontic miniscrew implants were included. Two authors independently performed study selection, data extraction, and risk-of-bias assessment. Results: The database survey yielded 24 articles. The risk-of-bias assessment revealed low methodological quality for the included studies. The most frequent adverse event reported was root injury with an associated periradicular lesion, vitality loss, pink discoloration of the tooth, and transitory loss of pulp sensitivity. Chronic inflammation of the soft tissue surrounding the miniscrew with mucosal overgrowth was also reported. The other adverse events reported were lesion of the buccal mucosa at the insertion site, soft-tissue necrosis, and perforation of the floor of the nasal cavity and maxillary sinus. Adverse events were also reported after miniscrew removal and included secondary bleeding, miniscrew fracture, scars, and exostosis. Conclusions: These findings highlight the need for clinicians to preliminarily assess generic and specific insertion site complications and side effects.

• The Korea Journal of Herbology
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• v.32 no.3
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• pp.71-78
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• 2017

Objectives : The various grape extracts derived from grape pulp, seed and skin, containing various types of polyphenols and flavonoids, have been known to have anti-inflammatory, antioxidant and improve cardiovascular condition as well as sun's damaging effects. However, there have been rare reports of various beneficial effects of grape fruit stem extract (GFSE), one of the waste products of grapes. We investigated anti-inflammatory and melanogenesis inhibitory effects of GFSE. Methods : One-hundred gram of grape fruit stem was extracted with 80% ethanol at room temperature for 3 days. After filtration, the ethanol was removed using vacuum evaporator, then lyophilized to obtain the dry extract which was stored at $-20^{\circ}C$ until used. NO levels were measured by using Greiss reagent. Prostaglandin $E_2$ ($PGE_2$) production was measured by ELISA assay. The expression levels of iNOS, COX-2, TRP-1 and TRP-2 were evaluated by western blot analysis. Results : GFSE reduced the level of nitric oxide and prostaglandin $E_2$ ($PGE_2$) production in a dose-dependent manner, compared to control. Expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein were also effectively inhibited by the GFSE. In a tyrosinase inhibitory activity, GFSE significantly reduced the tyrosinase activity and melanin content in a dose dependent manner, compared to control. GFSE also decreased the expression of tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2), known as a melanocyte-specific gene product involved in melanin synthesis. Conclusions : Therefore, these results indicated that GFSE had powerful anti-inflammatory and anti-melanogenic effects.

• Restorative Dentistry and Endodontics
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• v.27 no.2
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• pp.183-195
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• 2002

흑색 색소를 형성하는 그람음성 혐기성 세균은 급성 임상 증상을 가진 환자의 근관에서 자주 발견되는 세균으로서 세균 및 세균의 성분과 산물이 치근단 병소의 생성과 밀접하게 연관된 것으로 알려져 있다. 본 연구는 흑색 색소를 형성하는 그람음성 혐기성 세균 중 가장 발현율이 높은 Prevotella nigrescens가 배양된 세포에 미치는 세포 독성을 연구하고자 하였다. 두 가지 세포주 및 사람의 치은섬유모세포를 일차배양하여 사용하였으며, 세포주에 따른 독성 발현에 차이가 있는지를 비교하였다. P. nigrescens ATCC 33563 표준 균주 및 임상 균주로는 환자의 감염된 근관으로부터 165 rRNA primer를 사용한 중합효소 연쇄반응으로 P. nigrescens 6 균주를 동정하여 사용하였다. 세균배양액, 세균의 초음파 추출단백질 및 lipopolysaccharide (LPS)를 MC3T3-El 조골세포, NIH3T3 섬유모세포 및 치은섬유모세포에 첨가한 후 MTT분석법으로 세포의 활성을 측정하였으며, 세포의 형태학적 변화를 도립현미경으로 관찰하였다. 세균배양액을 100$\mu\textrm{l}$ 첨가한 경우는 세가지 세포주 모두에서 통계적으로 유의하게 세포의 활성을 억제하였다. 세균의 초음파 추출단백질 12.5$\mu\textrm{g}$/ml 와 25$\mu\textrm{g}$/ml 는 NIH3T3세포에 통계적으로 유의한 세포독성을 보였다. 세 가지 세포주에 대한 LPS의 세포 독성 효과는 첨가된 LPS의 농도 및 균주에 따라 다양하게 나타났다. 심하게 손상된 세포는 세포의 단일층이 수축되고 세포가 응집되었으며 세포가 배양용기의 바닥에서 떨어지는 양상이 도립 현미경하에서 관찰되었다. 본 연구의 결과 P. nigrescens가 숙주 반응을 조절하여 치수 및 치근단 병소의 유발 및 악화에 기여하는 세균으로 작용할 수 있음을 시사한다. 조직과 함께 제거하고 포르말린에서 48시간 고정시킨 후 파라핀에 포매한 다음에 micro-tome을 사용하여 6$\mu\textrm{m}$로 serial section을 시행하였다. 정중선 부위의 시편에 Hematoxylin-Eosin staining을 시행한 후 Olsson, Orstavik 그리고 Mjor 등의 방법에 따라 조직학적 변화를 관찰한 후 slight(1), moderate(2), severe inflammation(3)의 단계로 분류하였다. 얻어진 결과를 통계처리 프로그램인 Jandel사의 Sigmastat을 이용하여 Kruskal Wallis Test로 통계처리를 하였다. 결과 : (Table omitted) 결론 : 1) Pulp Canal Sealer를 제외한 모든 군에서 시간이 지남에 따라 유의성 있게 염증이 감소되는 양상을 보였다(p<0.05). 2) Pulp Canal Sealer는 1주, 2주, 12주에서 강한 염증반응을 보였다. 3) AH 26과 AH Plus에서는 1주, 2주에서 강한 염증반응을 보였으나 12주에서는 염증반응이 감소하였다. 4) 새로 개발된 봉함제 Adseal-1,2는 1주, 2주에서는 가장 약한 염증반응을 보이나 4주, 12주 후에는 AH Plus와 비슷한 수준의 염증 반응을 보였다. 5) Pulp Canal Sealer를 제외한 모든 군에서 인정할 만한 생체친화성을 보였다. 6) Adseal-2가 Adseal-1에 비하여 전반적으로 낮은 염증반응을 보였다. 7) 각 군간 결과의 차이에 통계적 유의성은 없었다(p>0.05).mmunity. Then, a hierarchical language is to defeat its own purpose.중 행정부가 북한에 대해 실시한 포용정책이 어떠한 성과를 거두고 어떠한 문제점을 간과하고 있는가에 대해 논의하고, 대북 정책의 새로운 지평을 논의하는 것을 목적으로 하고 있다. 1) 포용 정책은 세계의

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.275-280
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• 2009

Radicular cyst is a true epithelium lined cyst formed when epithelium at the apex of a nonvital tooth is stimulated by inflammation. It is the most common type of cyst in the oral cavity, but its frequency is low in the primary dentition. Treatment of large-sized cyst aims at conservation of adjacent structure and allowance of proper eruption of the successive permanent teeth in the primary dentition. Considering these two aspects, marsupialization or enucleation following decompression is recommended as a treatment means for large-sized radicular cyst. In this case, 8-year old boy visited the pediatric dentistry department. Yonsei University Dental Hospital, with the chief complaint of pain on the lower right area. Clinical and radiographic examinations revealed periapical radiolucent lesion on #84, which had previous pulp treatment and restorated with the stainless steel crown. Dislocation of its successive tooth, #44, was also observed. #84 was extracted and sent for biopsy. Through histologic examination, it was diagnosed as radicular cyst. Following its extraction, removable space maintainer was delivered, which was also used as a decompressor. During periodic check-up for next 22 months, favorable healing of the lesion and eruption of the successive tooth were observed.