• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.18.1-18.10
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• 2023

Objectives: This study aimed to determine whether collagen triple helix repeat containing-1 (CTHRC1), which is involved in vascular remodeling and bone formation, can stimulate odontogenic differentiation and angiogenesis when administered to human dental pulp stem cells (hDPSCs). Materials and Methods: The viability of hDPSCs upon exposure to CTHRC1 was assessed with the WST-1 assay. CTHRC1 doses of 5, 10, and 20 ㎍/mL were administered to hDPSCs. Reverse-transcription polymerase reaction was used to detect dentin sialophosphoprotein, dentin matrix protein 1, vascular endothelial growth factor, and fibroblast growth factor 2. The formation of mineralization nodules was evaluated using Alizarin red. A scratch wound assay was conducted to evaluate the effect of CTHRC1 on cell migration. Data were analyzed using 1-way analysis of variance followed by the Tukey post hoc test. The threshold for statistical significance was set at p < 0.05. Results: CTHRC1 doses of 5, 10, and 20 ㎍/mL had no significant effect on the viability of hDPSCs. Mineralized nodules were formed and odontogenic markers were upregulated, indicating that CTHRC1 promoted odontogenic differentiation. Scratch wound assays demonstrated that CTHRC1 significantly enhanced the migration of hDPSCs. Conclusions: CTHRC1 promoted odontogenic differentiation and mineralization in hDPSCs.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.51.1-51.10
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• 2020

Objectives: No studies have yet assessed vibration characteristics according to endodontic file length. Accordingly, the objective of the present study was to examine the vibration characteristics according to nickel-titanium file length and to compare these characteristics between different file systems. Materials and Methods: A total of 45 root canal models were divided into 3 experimental groups (n = 15 each) based on the file system used (ProTaper Gold [PTG], ProTaper Next, or WaveOne Gold [WOG]). Each experimental group was further divided into 3 subgroups according to file length (21, 25, or 31 mm). An electric motor (X-SMART PLUS) was used in the experiment. For each file system, vibrations generated when using a size 25 file were measured and used to calculate the average vibration acceleration. The differences in vibrations were analyzed using 1-way analysis of variance and the Scheffé post hoc test with a confidence interval of 95%. Results: In the PTG file system, significantly lower vibration acceleration was observed when using a 21-mm file than when using a 31-mm file. In the WOG file system, significantly stronger vibration acceleration was observed when using a 31-mm file than when using 21- or 25-mm files. Regardless of the file length, the WOG group exhibited significantly stronger vibration acceleration than the other 2 experimental groups. Conclusions: In clinical practice, choosing a file with the shortest length possible could help reduce vibrations. Additionally, consideration should be given to vibrations that could be generated when using WOG files with reciprocating motion.

• Restorative Dentistry and Endodontics
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• 제27권5호
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• pp.521-529
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• 2002

The purpose of this study was to compare the shaping time of two shaping methods and the leakage of three different obturation techniques. Ninty three canaled human molar teeth were used, which were randomly divided into two groups of forty teeth each and ten control teeth. After working length determination, the one group was prepared crown-down technique using rotary root canal instruments of GT rotary files .12/20, .10/20, .08/20 and .06/20 taper(Maillefer Instrument SA. Switzerland). The other group was instrumented with Gates Glidden burs(#1, #2, and #3) to coronal preparation and GT rotary files .08/20 and .06/30 taper to apical preparation. Shaping time was measured. After root canals were instrumented, they were divided to three subgroups and obturated as follows : Subgroup 1, obturated with single cone method Subgroup 2, obturated with lateral condensation : Subgroup 3, obturated with continuous wave technique. Three subgroups were obturated using non-standardized gutta-percha cone(Diadent, Korea, .06 or .08 taper) and AH-26(Dentsply DeTrey, Germany) as a root canal cement. Ten unobturated teeth served as positive and negative controls. After immersion in 2% methylene blue solution for 1 month, the teeth were washed during 24h. The teeth were demineralized in 10% nitric acid and dehydrated by immersion in 80, 90 and 100% ethyl alcohol. The teeth were finally cleared and stored in 100% methylsalicylate, and apical dye penetration was evaluated under stereomicroscope(Leica M420, LC, U.S.A)at $\times$8.75 magnification. Liner measurement of dye penetration was assessed with the use of digitalized image analysing system (analySIS, GmbH, Germany) The data were analysed statistically using independent T-test and Two-way ANOVA and Tukey test. The result were as follows 1. In canal prepared with GT$^{TM}$ rotary file, shaphing time taked more than the group of using Gates Glidden drill to coronal preparation without statistical significance (p>0.05) 2. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files showed significantly more apical leakage than those of lateral condensation and continuous wave technique regardless of shaping method (p<0.05). 3 The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed significantly more apical leakage than those of continuous wave technique regardless of shaping method (p<0.05). 4. Regardless of shaping method, The group of continuous wave obturation showed less apical leakage than those of lateral condensation without statistical significance (p>0.05). 5. The group of single cone obturation using canal preparation of GT$^{TM}$ rotary files and Gates Glidden drill showed more apical leakage than the group of lateral condensation using same shaping method with-out statistical significance (p＞0.05).

• Journal of Oral Medicine and Pain
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• 제32권2호
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• pp.227-239
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• 2007

1994년부터 2006년까지 부산대학교병원 구강내과에 내원하여 측두하악골관절염으로 진단받고 보존적 치료를 받은 환자 101명과 저작근장애로 진단받고 보존적 치료를 받은 환자 74명의 진료기록부를 통해 초진 시와 치료 종결 시의 증상, 시행된 치료방법, 치료기간, 치료횟수에 따른 치료 결과를 조사하였다. 그리고, 측두하악골관절염 환자의 초진 시 방사선 사진, 전산화 단층사진 및 단광자 방출 전산화 단층사진의 양성도, 관절잡음의 치료 전후 변화를 평가하여 다음과 같은 결과를 얻었다. 1. 골관절염군은 보존적 치료에 의해서 치료 결과가 좋았으나, 치료 종결 시 근육장애군에 비해서 증상의 개선이 미흡하였다. 2. 골관절염군의 파노라마 방사선 사진과 경두개 촬영사진의 양성도는 60%정도였으나, 전산화 단층사진과 단광자 방출 전산화 단층사진의 양성도는 90%이상이었다. 3. 치료 종결 시의 골관절염군의 관절잡음은 초진 시에 비해 유의하게 감소하였다. 4. 골관절염군은 대부분 물리치료, 투약, 교합안정장치로, 근육장애군은 대부분 물리치료, 투약으로 증상이 현저히 개선되었다. 5. 골관절염군은 6개월에서 2년의, 근육장애군은 6개월 미만의 치료가 필요하였다. 6. 골관절염군은 10회 이상으로, 근육장애군은 10회 미만의 치료로도 예후가 좋았다.

• Restorative Dentistry and Endodontics
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• 제30권1호
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• pp.31-37
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• 2005

본 실험은 resin 시편을 이용하여 미리 제작한 근관 내 불규칙 확장부에서 근관 충전용 sealer의 적용 방법에 따른 충전 효과를 평가해 보았다. Endo-training Bloc을 절단하여 사십 개의 규격화된 resin 블록 시편을 획득하였다. 각각의 시편에 $\#20$, 08taper GT 파일을 사용하여 근관을 형성하였고 근관에 손상이 가지 않도록 시편을 양분한 후 양분된 시편의 한 쪽 근관 벽에 다양한 근관 내 확장부를 표현하는 구를 형성하였다. 양분된 시편을 결찰하고 절단 부위를 밀봉하였으며 AH26 sealer를 사용하여 단일 cone 충전법으로 근관을 충전하였다. 네 가지의 근관 충전용 sealer의 적용방법을 이용하였다: A군, $\#20$ K-file : B군, ultrasonic file : C군, lentulo spiral: D군. EZ-Fill bi-directioanl spiral. 모든 시편은 $37^{\circ}\;100\%$ 상대습도에서 1주일간 보관한 후 각 시편을 근단에서 3mm, 4mm, 5mm 부위에서 수평으로 절단하고 각각의 절단면을 위상차현미경과 디지털 카메라를 이용하여 30배율로 관찰하고 촬영하였다. 관찰된 절단면은 scoring system을 이용하여 점수를 산정하였고 각 군 간의 통계적인 유의성 유무는 Fisher's Exact Test를 이용하여 시행하였다.

• Restorative Dentistry and Endodontics
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• 제35권6호
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• pp.479-485
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• 2010

연구목적: 이 연구의 목적은 레진 시멘트의 포스트 공간 내 적용 방법에 따른 포스트의 push-out접착 강도를 비교하는 것이었다. 연구 재료 및 방법: 30개의 발거된 하악소구치를 사용하여 시멘트의 적용 방법에 따라 세 그룹으로 나누었는데 lentulo-spiral을 이용하여 포스트 공간 내에 레진 시멘트를 적용하는 그룹 (group Lentulo), 직접 포스트 표면에 레진 시멘트를 도포하는 그룹 (group Direct), elongation tip을 이용하여 포스트 공간 내에 레진 시멘트를 적용하는 그룹 (group Elongation tip)으로 나누었다. 근관을 성형, 충전한 뒤 Rely-X post drill을 사용하여 포스트 공간을 형성하였고, Rely-X fiber post를 Rely-X Unicem 적용하여 광중합 하였다. 시편을 아크릴릭 레진에 포매 하고 저속 절단기로 치아 장축에 수직으로 절단하여, 하나의 치아에서 치관부, 중앙, 근단부의 세 개의 시편을 얻었다. 절단한 시편을 Universal Testing Machine으로 push-out 접착 강도를 측정하였다. 접착 실패가 일어난 시편을 수술용 현미경 하에서 관찰하여 그 실패 양상을 결정하였다. 결과: 치근의 위치에 따른 push-out 접착 강도는 유의한 차이를 보였으며, 전용의 elongation tip을 사용한 그룹이 가장 높은 push-out 접착 강도를 나타냈다. 결론: 레진 시멘트를 포스트에 직접 적용하거나 lentulo-spiral을 사용하는 기존의 방법에 비해 elongation tip을 사용하는 것이 self-adhesive 계면의 결함을 줄이고 근관치료한 치아의 수복 성공율을 높일 수 있을 것으로 생각된다.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.403-424
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• 1996

Cell culture methods have been used to assess the cytotoxicity of dental materials. Different paramaters are used to monitor cytotoxic effects. But it is difficult to compare each investigator's results with different methods. The objective of this study was to investigate cytotoxic effect of several retrograde filling materials according to cell lines and assay methods. Cytotoxicity of Bestalloy (Dogmyung, Korea), Prisma APH(Densply International Inc., U.S.A.), Clearfil FII (Kuraray Co., Japan), Fuji II (GC Co., Japan), Fuji II LC (GC Co., Japan) and IRM (Densply Co., U.S.A.) on L929, 3T3 and KB permanent cell lines was measured. Radiochromium, Lactate dehydrogenase (LDH) release method and colorimetric assays, namely neutral red (NR) and MTT were used. Each material was mixed according to the manufacturer's instruction. They were tested as solid and extracted state. Cell culture media were added to each mixed or solid materials then the solution was collected and used as extract solutions. Solid Fuji II showed mild cytotoxicity on three cell lines using radiochromium release method. There was no difference in cytotoxicity of extract solution group using radiochromium release method. In colorimetric assay immediate Fuji II group and all the IRM groups showed severe cytotoxic effect. Difference in cyctotoxicity was due to rather kinds of cell lines than assay methods. Solid Fuji II and IRM showed mild cytotoxicity on three cell lines. But extract solutions had different cytotoxic effect according to cell lines using LDH release assay. Light-cured glass ionomer had mild to moderate degree of cytotoxicity on three cell lines. Cytotoxicity was affected by specimen prepaton. Susceptibility of each cell ines were also affected by assay emthods. It was suggested that cytotoxicity study using only one cell line and/or assay method might not accurately reflect the real toxic nature of dental biomaterials.

• Restorative Dentistry and Endodontics
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• 제40권4호
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• pp.332-333
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• 2015

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.13-25
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• 1999

P. endodontalis which was known to be associated with the infected root canals and periapical lesions is very difficult to detect by culture methods or traditional methods. Detection of bacteria using polymerase chain reaction(PCR) for 16S ribosomal DNA(rDNA) is fast, simple, and accurate with relatively small amount of target cells. 16S rDNA consist of conserved regions those are same to all species, and variable regions which represent species specificity. The 16S rDNA sequences of P. endodontalis and P. gingivalis were aligned and two highly variable regions were selected as a pair of species specific oligonucleotide primers for P. endodontalis. And then the pair of primers for PCR amplification was synthesized to identify P. endodontalis. The sequences of the species specific primers for the 16S rDNA of P. endodontalis were as follows ; sense primer[endo1]: 5'-CTATATTCTTCTTTCTCCGCATGGAGGAGG-3' antisense primer[endo2]: 5'-GCATACCTTCGGTCTCCTCTAGCATAT-3' In this study, for the identification of P. endodontalis without culture from the mixed clinical samples, PCR was done with species specific primers for the 16S rDNA sequences of P. endodontalis. The results were as follows : 1. The species specificity of the primers for the 16S rDNA of P. endodntalis was determined by the PCR methods. About 490bp amplicon which was specific only for P. endodntalis was produced with P. endodontalis. No amplicon was produced by PCR with other strains similar to P. endodontalis. 2. The synthesized species specific primers reacted with conventionally identified P. endodontalis which we have in conservative dentistry laboratory. 3. The identification of P. endodontalis using PCR technique with samples collected from infected root canals or periapical lesions was more sensitive than that of culture methods. 4. Seven samples revealed including P. endodontalis by PCR technique. Five of them were related with pains, two of them with sinus tract, three of them with foul odor, and three of them with purulent drainage. P. endodontalis was shown to have great relation with pains.

• Restorative Dentistry and Endodontics
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• 제34권5호
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• pp.390-396
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• 2009

이 실험의 목적은 $EndoVac^{(R)}$과 $EndoActivator^{(R)}$를 이용한 근관세척시 근관 내 접종된 Enterococcus faecalis의 제거 효율을 기존의 irrigation needle을 이용한 방법과 비교 평가하고자 함이다. 발거된 70개의 단근치를 사용하였으며 .04 taper ProFile #40까지 근관형성 후 치아를 멸균하고 근관에 E. faecalis를 접종하고 배양하였다. 치아는 근관세척 방법에 따라 20개씩 3개의 실험군과 2개의 대조군으로 나누었다. 2.5% 치아염소산나트륨을 사용하여 근관세척 시행 후 일차 표본을 채취하였고, 다시 근관 내에 배양액을 채우고 24시간 동안 배양 후 이차 표본을 채취하였다. 표본은 colony forming units (CFU) 값을 얻기 위해 BHI agar plate에 배양하였다. 일차 표본 결과에서는 모든 실험치아 중 기존의 근관세척 방법을 이용한 하나의 근관에서 양성 배양을 보였다. 이차 표본 결과에서는 $EndoVac^{(R)}$ 실험군에서 가장 적은 양성 배양을 보였으며, 기존의 근관세척 방법과 비교시 통계적으로 유의한 차이를 보였다. 실험 결과에 따르면 $EndoVac^{(R)}$은 근관 내 접종된 E. faecalis의 제거에 있어 기존의 근관세척 방법보다 더 좋은 효율을 보였다.