• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.17.1-17.8
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• 2023

The present report describes the endodontic treatment of an Oehlers type II dens invaginatus in a maxillary lateral incisor with 5 root canals, an extremely rare condition. Apical periodontitis and related symptoms were noted. Cone-beam computed tomography was used to aid the diagnosis, reveal tooth morphology, and assist in canal location. The pulp chamber was carefully accessed, and the root canals were explored under magnification. All root canals were prepared with an R25 Reciproc Blue system and sodium hypochlorite (NaOCl) irrigation. After initial preparation, a self-adjusting file (SAF) with NaOCl and ethylenediaminetetraacetic acid was used to complement the disinfection. Additionally, calcium hydroxide medication was applied. Vertical compaction was used to fill the canals with a calcium silicate-based endodontic sealer and gutta-percha. After 12 months, the patient exhibited healing of the periapical region, absence of symptoms, and normal dental function. In conclusion, this nonsurgical treatment protocol was successful in promoting the cure of apical periodontitis. Both complementary disinfection with an SAF and use of calcium hydroxide medication should be considered when choosing the best treatment approach for dens invaginatus with very complex anatomy.

• Restorative Dentistry and Endodontics
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• 제40권4호
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• pp.290-298
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• 2015

Objectives: Sodium hypochlorite (NaOCl) is an excellent bactericidal agent, but it is detrimental to stem cell survival, whereas intracanal medicaments such as calcium hydroxide ($Ca[OH]_2$) promote the survival and proliferation of stem cells. This study evaluated the effect of sequential NaOCl and $Ca(OH)_2$ application on the attachment and differentiation of dental pulp stem cells (DPSCs). Materials and Methods: DPSCs were obtained from human third molars. All dentin specimens were treated with 5.25% NaOCl for 30 min. DPSCs were seeded on the dentin specimens and processed with additional 1 mg/mL $Ca(OH)_2$, 17% ethylenediaminetetraacetic acid (EDTA) treatment, file instrumentation, or a combination of these methods. After 7 day of culture, we examined DPSC morphology using scanning electron microscopy and determined the cell survival rate with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We measured cell adhesion gene expression levels after 4 day of culture and odontogenic differentiation gene expression levels after 4 wk using quantitative real-time polymerase chain reaction. Results: DPSCs did not attach to the dentin in the NaOCl-treated group. The gene expression levels of fibronectin-1 and secreted phosphoprotein-1 gene in both the $Ca(OH)_2$- and the EDTA-treated groups were significantly higher than those in the other groups. All $Ca(OH)_2$-treated groups showed higher expression levels of dentin matrix protein-1 than that of the control. The dentin sialophosphoprotein level was significantly higher in the groups treated with both $Ca(OH)_2$ and EDTA. Conclusions: The application of $Ca(OH)_2$ and additional treatment such as EDTA or instrumentation promoted the attachment and differentiation of DPSCs after NaOCl treatment.

• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.17.1-17.7
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• 2018

Iatrogenic perforations negatively impact the outcome of endodontic treatments. Studies on prognostic factors showed that perforations in the coronal third of the root with periodontal pocket formation have an unfavorable prognosis. A 36-year-old female was referred for endodontic evaluation of tooth #13 with a history of an iatrogenic perforation, happened 3 years ago. There was a sinus tract associated with perforation, 10 mm probing on the mesial and mesio-palatal, bleeding on probing, radiolucent lesion adjacent to the perforation and complete resorption of the interdental bone between teeth #13 and #12. After the treatment options were discussed, she chose to save the tooth. The tooth was accessed under rubber dam isolation, the perforation site was cleaned and disinfected using 0.5% sodium hypochlorite and sealed with calcium-enriched mixture cement. Eighteen months after treatment the tooth was functional and asymptomatic. The probing depths were normal without bleeding on probing. Radiographically, the interdental crestal bone formed between teeth #13 and #12. Despite all negative prognostic factors in this case (i.e., perforations in the coronal third, pocket formation, and radiolucent lesion), healing was unexpectedly achieved via non-surgical repair of the perforation. Further research on biological aspects of healing in the periodontium following iatrogenic perforations are recommended.

• 생명과학회지
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• 제7권3호
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• pp.212-218
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• 1997

The studies were conducted to explore the dffects of growth or survival against various factors and plasmid profiles of 49 Y. enterocolitica isolated from springs water. In the presence of calcium hypochlorite, y. enterocolitica was entirely extinguished by exposure for 33 hours at 0.8 ppm concentration, and was grown up to 7% NaCl, but not at 95 NaCI. Y. enterocolitica was presented optimal growth at pH 7.0 anad 9.0, and not allowth the growth at pH3.0, 5.0 and 11.0. The optimal temperature for growth of Y. enterocolitica was 25$\circ$C and 35$\circ$C, and allowed the growth at refrigerant temperature, 5$\circ$C. Y. enterocolitica was remarkably decreased by exposure for 30 seconds under UV light, and entirely extinguished by exposure for 90 seconds. Therefore, UV light was effective for sterilization of Y. enterocolitica. Fourty-nine strains of Y. enterocolitica were harbor plasmid DNA of approximately 46 Kb molecular weight.

• 펄프종이기술
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• 제33권3호
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• pp.84-99
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• 2001

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulp(alkaline sulfite-${Na_2}{S_2}{O_4}$) was bleached using the various kinds of bleaching agents by the two-stages bleaching methods. And, physical properties of pulps bleached with eight kinds of two-stages bleaching methods were tested. The results of this study were as follow; 1. The first-stage bleaching was conducted under the proper conditions with chlorine(C). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of CH stage were determined to be 0.3% concentration of calcium chlorite, $30^{\circ}C$ of reaction temperature and 20min. of reaction time. For CP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.5%, $60^{\circ}C$ and 90min., respectively. And for CY stage, the proper conditions were 0.5% concentration of sodium hydrosulfite, $40^{\circ}C$ of reaction temperature and 90min. of reaction time. 2. The first-stage bleaching was conducted under the proper conditions with chlorine dioxide(D). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of DH stage were determined to be 0.5% concentration of calcium chlorite, $25^{\circ}C$ of reaction temperature and 5min. of reaction time. For DP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.0%, $70^{\circ}C$ and 90min., respectively. And for DY stage, the proper conditions were 0.3% concentration of sodium hydrosulfite, $50^{\circ}C$ of reaction temperature and 20min. of reaction time. 3. The first-stage bleaching was conducted under the proper conditions with calcium chlorite(H). kAnd then, the proper conditions related to the hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of HP stage were determined to be 0.3% concentration of hydrogen peroxide, $30^{\circ}C$ of reaction temperature and 60min. of reaction time. For HY stage, the proper conditions of concentration of sodium hydrosulfite, reaction temperature and reaction time were 2.5%, $60^{\circ}C$ and 30min., respectively. 4. When the rice-straw chemical pulps were bleached with eight kinds of two-stages bleaching methods in the proper conditions mentioned above, respectively, the final brightnesses after CH, CP, CY, DH, DP, DY, HP, and HY bleachings were 62.0, 74.3, 61.4, 58.9, 66.9, 62.9, 50.4 and 60.1, respectively. And strengthes of pulps bleached with DP and DH methods were comparatively higher than those of pulps bleached with other bleaching methods.

• 한국식품과학회지
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• 제50권2호
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• pp.172-178
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• 2018

마늘과 생강 내 자체 항균 성분인 알리신과 진저론, 쇼가올에 의해 분쇄한 다진 상태의 경우 자생 총세균이 $10^1CFU/g$ 감균되는 살균 효과를 나타내었다. 1% (w/w) 농도의 시트르산, 산화칼슘과 200 ppm 차아염소산나트륨 용액에 각각 1시간 침지한 통마늘과 통생강에서 $10^1CFU/g$ 내외의 총세균수 감소를 가져와 90%의 살균율을 보였다. 또한 분쇄한 다진 마늘을 1% (w/w) 시트르산, 산화칼슘 용액에서 각각 1시간 침지한 결과 $10^1CFU/g$와 $10^4CFU/g$ 내외의 총세균수 살균 효과의 증가를 가져왔으며 다진 생강에서도 산화칼슘 용액 침지시 다진 마늘과 유사한 항균력의 현저한 상승 효과를 보였다. $90-95^{\circ}C$, 30-40초 데치기를 실시한 결과 항균제 용액 침지에 의한 항균 효과 보다는 가열에 의한 살균 효과가 크게 나타나 통마늘과 통생강에서 총세균은 $10^3-10^4CFU/g$, 진균류는 $10^1-10^2CFU/g$ 내외 감균 되었다. 통마늘에 비해 총세균과 진균이 30-70% 많이 자생하고 있는 통생강에 대한 살균 효과를 높이기 위해 차아염소산나트륨 침지 후 데치기를 병합 적용한 결과 총세균과 내열성을 보유한 바실루스 세균에 대하여$10^1CFU/g$ 내외의 감균 효과가 증가하였다. 이상의 연구를 통해 항균제와 데치기를 이용한 마늘, 생강의 감균법이 향신 채소를 사용한 다양한 가공식품의 가열살균 강도를 저감화시켜 품질 향상을 도모할 수 있는 효과적인 전처리 방법으로 활용 가능함을 알 수 있었다.

• Restorative Dentistry and Endodontics
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• 제40권2호
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• pp.104-112
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• 2015

Objectives: This study was performed to investigate the effects of different intracanal medicaments on chemical structure and microhardness of dentin. Materials and Methods: Fifty human dentin discs were obtained from intact third molars and randomly assigned into two control groups and three treatment groups. The first control group received no treatment. The second control group (no medicament group) was irrigated with sodium hypochlorite (NaOCl), stored in humid environment for four weeks and then irrigated with ethylenediaminetetraacetic acid (EDTA). The three treatment groups were irrigated with NaOCl, treated for four weeks with either 1 g/mL triple antibiotic paste (TAP), 1 mg/mL methylcellulose-based triple antibiotic paste (DTAP), or calcium hydroxide [$Ca(OH)_2$] and finally irrigated with EDTA. After treatment, one half of each dentin disc was subjected to Vickers microhardness (n = 10 per group) and the other half was used to evaluate the chemical structure (phosphate/amide I ratio) of treated dentin utilizing attenuated total reflection Fourier transform infrared spectroscopy (n = 5 per group). One-way ANOVA followed by Fisher's least significant difference were used for statistical analyses. Results: Dentin discs treated with different intracanal medicaments and those treated with NaOCl + EDTA showed significant reduction in microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.05) compared to no treatment control dentin. Furthermore, dentin discs treated with TAP had significantly lower microhardness (p < 0.0001) and phosphate/amide I ratio (p < 0.0001) compared to all other groups. Conclusions: The use of DTAP or $Ca(OH)_2$ medicaments during endodontic regeneration may cause significantly less microhardness reduction and superficial demineralization of dentin compared to the use of TAP.

• Restorative Dentistry and Endodontics
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• 제47권1호
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• pp.10.1-10.11
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• 2022

Objectives: This study aimed to investigate the color stability, solubility, and surface characteristics of 3 calcium silicate-based cements (CSCs) after immersion in different solutions. Materials and Methods: ProRoot white mineral trioxide aggregate (MTA), Biodentine, and Endosequence Root Repair Material (ERRM) were placed in cylindrical molds and stored at 37℃ for 24 hours. Each specimen was immersed in distilled water, 5% sodium hypochlorite (NaOCl), 2% chlorhexidine, or 0.1% octenidine hydrochloride (OCT) for 24 hours. Color changes were measured with a spectrophotometer. Solubility was determined using an analytical balance with 10^-5 g accuracy. The surface characteristics were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. Data were analyzed using 2-way analysis of variance, the Tukey test, and the paired t-test. Results: MTA exhibited significant discoloration in contact with NaOCl (p < 0.05). White precipitation occurred on the surfaces of Biodentine and ERRM after contact with the solutions, and none of the materials presented dark brown discoloration. All materials showed significant solubility after immersion in the solutions (p < 0.05), irrespective of the solution type (p > 0.05). The surface topography and elemental composition of the samples showed different patterns of crystal formation and precipitation depending on the solution type. Conclusions: All materials presented some amount of solubility and showed crystal precipitation after contact with the solutions. Biodentine and ERRM are suitable alternatives to ProRoot MTA as they do not exhibit discoloration. The use of OCT can be considered safe for CSCs.

• Restorative Dentistry and Endodontics
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• 제34권6호
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• pp.508-514
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• 2009

이 실험의 목적은 근관 내에 충전된 수산화칼슘의 제거 시 치근단 1/3에서 기존의 근관세정법과 $EndoActivator^{(R)}$, $EndoVac^{(R)}$ system의 세정 효율을 비교하고, 근관 세정 중 치근단공 개방 확인의 영향에 대해 평가하고자 함이다. 60개의 단근치를 사용하였고 ISO #35까지 근관성형 후 수산화칼슘을 충전하였다. 근관 세정법과 치근단공 개방 확인 유무에 따라 6개 실험군으로 나누어 세정하였다. 실험 치아를 양분하여 치근단 3 mm에서 근관 면적에 대한 잔존 수산화칼슘 면적의 백분율을 측정하였다. 실험결과 $EndoActivator^{(R)}$, $EndoVac^{(R)}$군이 기존의 근관 세정법 군에 비해 유의하게 높은 제거효율을 나타냈으며 (p<0.05), 치근단공 개방 확인 유무에 따른 유의한 차이는 나타나지 않았다. 이 실험 결과에 따르면 기존의 근관세정법으로 효과적인 세정이 불가능했던 근관의 치근단 1/3부위에서 $EndoActivator^{(R)}$, $EndoVac^{(R)}$ system과 같은 근관 세정법이 효과적인 대안이 될 수 있다는 결론을 얻었다.

• Applied Biological Chemistry
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• 제39권1호
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• pp.25-31
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• 1996

식물체내 칼모듈린과 칼모듈린 메틸화의 기능에 대한 정보를 얻기 위하여 칼모듈린 유도체($lys{\rightarrow}ile\;115$ 칼모듈린)를 발현시킬 수 있고 하이그로마이신(Hygromycin) 내성을 보일 수 있는 형질전환 담배 식물체와 하이그로마이신 내성만 보일 수 있는 형질전환 담배 식물체(대조구)가 Agrobacterium-mediated 형질전환을 통해 만들어 졌다. 이들 형질전환 담배 식물체로 부터 얻은 씨앗의 하이그로마이신 내성과 민감성에 대한 비는 예상대로 3 : 1을 보였다. Western blot과 Chemiluminescence 방법을 병행하여 형질전환 식물체($F_1$)의 잎으로 부터 칼모듈린 단백질을 검출한 결과 칼모듈린 단백질이 발현 되었음이 확인되었다. 두 형질 전환 담배 식물체로 부터 얻은 씨앗의 발아에 미치는 표피살균제의 영향을 조사해본 견과 칼모듈린 형질전환체의 씨앗은 살균수의 처리만으로도 MS 배지에서 씨앗 주변에 곰팡이 등의 오염없이 정상 발아되었으며, 대조구는 살균수와 차아염소산나트륨 용액(유효 염소 함유량 4%)을 1 : 1 배합하여 처리해주어야 오염으로 부터 벗어날 수 있었다. 칼모듈린 유도체를 발현 시키는 담배 씨앗과 대조구 담배 씨앗의 발아에 미치는 칼슘 농도의 영향을 조사해본 결과 저 농도의 칼슘을 함유한 MS배지에서는 초기 발아율에 있어 별 차이가 없었지만 고농도(예, 30mM)의 칼슘 함유배지에서는 칼모듈린 형질전환체 씨앗의 발아가 대조구 형질전환 식물체 씨앗의 발아에 비해 월등하게 잘 되었다. 이와 같은 결과들로 부터 칼모듈린 유도체의 담배 세포내 발현은 각종 환경적 요인에 대한 담배 씨앗의 적응능력을 증진시키는 것으로 제안할 수 있겠다.