• 대한치과의사협회지
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• 제48권11호
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• pp.803-812
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• 2010

Regenerative endodontic procedure (REP) is a treatment option to replace damaged pulp tissue with the viable tissue which restores the normal function of the pulp-dentin complex. Possible reason for doing REP is not clearly known, however, clinicians perform REP in order to recover the histological structure as well as function of the traumatized and diseased tooth so that this tooth can restore its original root shape and thickness. This REP can be explained by the concept of revascularization or revitalization after induction of blood clot formation in the canal space. For this purpose, several treatment strategies have been suggested. In this regard, the rationale for the application of triantibiotics, calcium hydroxide or mineral trioxide aggregate is discussed in this paper. As a result, we will try to find the best method for REP by reviewing each available technique and their advantages and disadvantages.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.586-586
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• 2003

In the infected immature tooth with periapical involvement, the pulp is considered to hardly exist in the canal and periapical area. Such a tooth receives apexification procedure, because revascularization of the pulp chamber is in principle not expected. Apexification is beneficial to induce further development of an apex to close the foramina, but does not promote the thickness of the entire canal wall dentin. It may be possible for the pulp to be only partially necrotic and infected when an extremely large communication from the pulp space to the periapical tissues exists with a very young tooth. If this were the case, vital pulp in the apical part of the canal could proliferate new pulp into the coronal pulp space by the successful removal and disinfection of the necrotic infected coronal pulp.(omitted)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권2호
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• pp.137-145
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• 1993

The purpose of this study was to observe the effect on teeth and tibia bone histopathologically in rats by the richitogenic diet. For this purpose, 48 sprague-dewley rats, weighing 80g or more, divided into 6 groups, and sacrificed on the 1st, 2nd, 3rd, 4th, 5th, 6th weeks after experiments respectively. The tissues contain tooth, and tibial bone were fixed in 10% normal formalin solution, decalcified in Plank-Rychlo solution, embedded in paraffin, sectioned in $6-8{\mu}$ as usual manner, the tissues were stained in hematoxylin eosin, and examined hisopathologically. Follow results were attained 1. Pyknotic appearance of odontoblastic layer was noticed on the 1st week, and increased on the 2nd weeks, and it is appeared that degeneration and dearrangements of odontoblasts on the 4 weeks. But a little recovered on the 6th weeks. 2. The thickness of predentin layer was increased on the 2nd weeks, and increased remarkedly on the 3rd weeks and reached the maximum on the 5th weeks. 3. The interglobular dentin was appeared in spotty shape on the 2nd weeks, and increased on the 4th, 5th, weeks, and large amount of inter-globular dentin was appearanced on the 6th weeks. 4. It is appeared that enamel hypoplasia on the 4th weeks. 5. Epiphyseal and metaphyseal plate of tibia was increased from/on the 2nd weeks, increased maximumly on the 5th weeks. And pyknotic, dearrangements, and hyperchromatic appearances of chondrocytes on the plate were increased on the 1st week.

• Restorative Dentistry and Endodontics
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• 제39권4호
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• pp.276-281
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• 2014

Objectives: The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods: The apical 3 mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results: There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions: Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

• Restorative Dentistry and Endodontics
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• 제35권5호
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• pp.353-358
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• 2010

연구목적: 본 연구는 직접수복용 레진 (Filtek Z350, Supreme XT)과 기공용 레진 (Sinfony)으로 제작한 레진 인레이를 투과하는 광중합기의 광강도를 측정하고 레진 인레이를 구성하는 색조에 따라 투과되는 광강도를 측정하였다. 연구 재료 및 방법: A3 색조의 레진 인레이를 Z350 A3 한 가지 색조로 제작한 것과 Supreme XT A3B와 A3E 두 가지 색조로 제작한 것을 이용하였으며 Sinfony는 제조사의 지시에 따라 A3, E3, T1 세 가지 색조로 제작하였고 두께는 1.5 mm로 통일하였다. 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar S10)를 이용하여 레진 인레이를 투과하는 광강도를 휴대용 광강도 측정기 (Cure Rite)로 측정하였다. 각 레진의 색조가 광강도의 투과에 미치는 영향을 분석하기 위해 0.5mm 두께로 레진 시편을 제작하여 광강도를 측정하였다. 결과: Z350 A3로 제작한 레진 인레이를 투과한 광강도가 가장 낮았으며, 다음으로 Supreme XT A3B와 A3E로 제작한 레진 인레이, 그리고 Sinfony A3, E3, T1으로 제작한 레진 인레이 순으로 광강도가 유의하게 증가하였다 (p < 0.05). 0.5mm의 레진 시편을 투과한 광강도를 측정한 결과 dentin shade인 Sinfony A3, Z350 A3, Supreme XT A3B가 가장 낮았으며, enamel shade인 Supreme XT A3E, Sinfony E3, 그리고 translucent shade인 Sinfony T1 순으로 유의하게 증가하였다 (p < 0.05). 결론: 레진 인레이를 제작할 경우 단색의 직접 수복용 레진을 사용하기 보다는 기공용 레진의 dentin shade, enamel shade, translucent shade를 모두 사용하는 것이 레진 인레이 하방으로 더 많은 중합광을 투과시킬 수 있는 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제28권1호
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• pp.23-33
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• 2003

The purpose of this study was to compare in vitro interfacial relationship of restorations bonded with three self-etching primer adhesives and one self-etching adhesive. Class I cavity preparations were prepared on twenty extracted human molars. Prepared teeth were divided into four groups and restored with four adhesives and composites Clearfil SE $Bond/Clearfil^{TM}$ AP-X (SE), UniFil $Bond/UniFil^{\circledR}$ F (UF), FL $Bond/Filtek^{TM}$ Z 250 (FL) and Prompt $L-Pop/Filtek^{TM}$ Z 250 (LP) After storing in distilled water of room temperature for 24 hours, the specimens were vertically sectioned and decalcified. Morphological patterns between the enamel/dentin and adhesives were observed under SEM. The results of this study were as follows : 1. They showed close adaptation between enamel and SE, UF and FL except for LP. 2. The hybrid layer in dentin was $2{\;}\mu\textrm{m}$ thick in SE, $1.5{\;}\mu\textrm{m}$ thick in UF, and $0.4{\;}\mu\textrm{m}$ in both FL and LP. So, the hybrid layers of SE and UF were slightly thicker than that of FL and LP. 3. The lengths and diameters of resin tags in UF and FL were similar, but those of LP were slightly shorter and slenderer than those of SE. 4. The resin tags were long rod shape in SE, and funnel shape in other groups Within the limitations of this study, it was concluded that self-etching primer adhesives showed close adaptation on enamel. In addition, the thickness of hybrid layer ranged from $0.4-1.5{\;}\mu\textrm{m}$ between adhesives and dentin. The resin tags were long rod or funnel shape, and dimension of them was similar or different among adhesives.

• Journal of Oral Medicine and Pain
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• 제40권4호
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• pp.146-154
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• 2015

Purpose: The purpose of present study was to develop a method for assessing the chronological age of Korean adults based on the relationship between age and size of pulp cavity using dental radiographs of mandibular first molars. Methods: A total of 325 dental radiographs of Korean adults with known age and gender were selected for the study (199 males and 126 females) which were taken in the period between January 2009 and June 2014 at the Pusan National University Dental Hospital. The measurements were carried out on both orthopantomographs (OPGs) and intraoral periapical radiographs of mandibular first molar and the following ratios were calculated: pulp chamber floor height ratio (F/L), pulp chamber ceiling height ratio (R/L), and pulp chamber depth ratio (D/L). Results: The ratios of measurements on intraoral periapical images of mandible first molar generally produce more reliable data than the measurements on OPGs. The pulp chamber floor height ratio and pulp chamber thickness ratio showed significant correlation with age, whereas the pulp chamber ceiling height ratios showed weak correlation with age. It was found that the best correlations between the ratios and age were found for pulp chamber thickness ratios (r=-0.731 to -0.751). The multiple regression models were derived using 3 ratios that were significantly correlated with age. The determination coefficients ($R^2$) of the models ranged from 0.556 to 0.596. Conclusions: Our results indicate that the pulp chamber thickness and pulp chamber floor height in mandibular first molar are an age-dependent variable in adults which can be used to estimate age with reasonable accuracy. The higher image quality of dental radiographs will probably narrow the age estimation error and improve dental age estimation.

• Restorative Dentistry and Endodontics
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• 제29권2호
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• pp.177-184
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• 2004

본 연구는 광중합형 상아질 접착제에서 광조사 시간의 증가가 접착제 표면의 미중합층에 대한 영향과 그에 따른 전단접착강도에 대해 연구하고자 120개의 치아를 아크릴 몰드에 식립한 후 상아질이 노출되도록 연마하였다. 3종류의 접착제 〔All Bond2 (AB2), One-Step (OS) and Adper Prompt (AP)〕를 40개 치아에 제조사의 지시대로 도포한 후 각각 다른 광조사 시간 (10, 20, 30 and 60sec)동안 광조사 하고 복합레진을 접착한 24시간 후 전단접 착강도를 측정하였다. 미중합층의 두께와 중합률은 슬라이드 글라스와 FT-NIR을 이용하여 FT-NIR spectrum에서의 peak height를 비교 측정하여 다음과 같은 결론을 얻었다. 1. 전단접착강도에서 AB2는 20초 이후 감소하고, AP는 30초까지 증가하였으며,OS는 차이를 보이지 않았다. 2. 미중합층 두께는 3가지 접착제 모두 유의성 있는 차이를 보이지 않았다. 3. 중합률에서 OS는 10초와 나머지군 사이에 유의성 있는 차이를, AP는 60초에서 유의성 있게 증가되고, AB2의 경우 차이를 나타내지 않았다.

• Restorative Dentistry and Endodontics
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• 제34권3호
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• pp.232-239
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• 2009

본 실험은 발거 된 하악 대구치의 근심 근관을 스테인레스 강 K 파일과 니켈 티타늄 전동식 파일로 근관 성형했을 때 anticurvature filing 방법의 효용성을 평가하고자 했다. 30개의 발거된 하악 대구치 60개의 근심근관을 성형 방법과 기구에 따라 3개의 군으로 나누고 근단부 근관을 30번 크기로 일정하게 확대하였다. 1군은 스테인레스 강 K 파일을 사용해 circumferential filing technique을, 2군은 스테인레스 강 K 파일을 사용해 anticurvature filing technique을 3군은 니켈 티타늄 ProFile 06 series를 사용해 anticurvature filing technique으로 근관을 성형하였다. MCT를 이용해 얻은 술전, 술후 절단면 상을 중첩해 치근단 공에서 1mm 떨어진 지점에서부터 0.5mm 간격으로 위험부위 (danger zone)의 삭제량을 비교하였다. micro-computed tomography system (skyscan-1076, SKYSCAN, Antwerpen, Belgium)을 이용해 얻은 술전 술후 절단면 상을 중첩해 치근단 공에서 1mm떨어진 지점에서부터 0.5mm 간격으로 위험부위 (danger zone)의 삭제량을 비교하였다. danger Bone 폭경의 변화량은 one-way ANOVA를 이용하여 유의성 검정을 하였고 Tukey test를 이용하여 사후검정 하였다. 그 결과, 스테인레스 강 파일을 사용한 경우 circumferential filing으로 근관 성형한 것보다, anticurvature filing으로 근관 성형한 경우가 치관부 1/3부위($7.5{\sim}8.5mm$)의 danger zone의 삭제량이 유의성 있게 적었고 (P<0.05), 니켈 티타늄을 사용하여 anticurvature filing으로 근관 성형한 경우는 danger zone의 중간 1/3부위 ($3.5{\sim}6mm$)의 삭제량이 유의성 있게 적었다 (P<0.05). 니켈티타늄을 사용하여 anticurvature filing으로 근관 성형한 경우, 스테인레스 강 파일을 사용하여 anticurvature filing으로 근관 성형한 경우보다 $3.5{\sim}6mm$의 삭제량이 유의성 있게 적었다 (P<0.05).

• Restorative Dentistry and Endodontics
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• 제30권6호
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• pp.450-460
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• 2005

본 연구에서는 복합레진의 중합수축시 와동의 형태, 접착층의 성숙도, 및 와동의 부피가 와동저의 접착면에 발생되는 중합수축응력에 미치는 영향을 평가하였다. 1급 와동 충전시의 응력발생을 모방하기 위해, 98개의 대구치를 $2\times2\times2$ 실험군에 무작위로 분배하고 교합면 상아질을 평탄하게 연마한 후, 복합레진 충전을 위한 몰드의 역할을 할 수 있는 구멍을 가진 iris를 올려놓고 복합레진을 bulk-filling법으로 충전하였다. 각각의 변수로서 와동 형태에 관하여는 iris 재질 (접착제를 도포한 상아질 iris: 높은 C-factor, Teflon 처리된 금속 iris: 낮은 C-factor), 접착층의 성숙도에 관하여는 2종의 접착제 (Scotchbond Multi-purpose와 Xeno III), 와동의 부피에 관하여는 iris내 구멍의 직경 (직경 1 또는 $3mm{\times}높이$) 5mm)을 달리하여 전단접착강도를 측정하였다 와동의 C-factor가 클수록, 접착층의 성숙도가 우수할수록 그리고 부피가 클수록 접착력은 유의하게 감소하였다. 복합레진이 중합될 때, 와동의 형태적 제한에 따라 레진-상아질 접착계면에 발생되는 중합수축응력은 접착이 우수할수록 복합레진의 부피가 클수록 증가되므로, C-factor를 정의할 때 와동의 형태뿐 아니라, 접착층의 성숙도와 복합레진의 부피도 함께 고려되어야 된다.