• 치위생과학회지
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• 제16권5호
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• pp.349-354
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• 2016

2015년 실시한 국민구강실태조사에 따르면 우리나라 만 12세 아동들의 우식경험영구치지수(DMFT index)는 1.9로 주요 OECD 국가들의 평균인 1.6에 거의 근접한 것으로 조사되었다. 본 연구의 목적은 인접면 우식증의 진단에 있어 새로 개발된 $Qraypen^{TM}$의 효능을 기존의 방법인 시진 및 구내 치근단 방사선 사진과 비교 평가하고, 임상 적용 시의 문제점을 파악하여 차후 $Qraypen^{TM}$에 필요한 개선안을 제시함과 아울러 치아우식증의 예방 및 초기 우식증 재광화 방법에 대한 기초 연구자료를 마련하고자 하였다. 학교 구강검진을 목적으로 내원한 학령기의 혼합치열을 가진 32명의 어린이들을 대상으로 구강검진 2회, 구치부 치근단 방사선 필름 판독 2회 그리고 구치부 인접면 $Qraypen^{TM}$ 이미지 판독 2회를 실시하고 비교한 결과 $Qraypen^{TM}$ 영상은 변연융선이 파괴되지 않은 유구치의 인접면 우식증의 탐지에 효과적이었다. 또한 방사선 촬영 결과와 비교해 보니 차이가 없음을 확인하였다. 그러나 인접면 우식증이 상아질까지 진행되어 병소가 성숙하여야 뚜렷한 붉은색 형광을 관찰할 수 있었기에 우식 병소의 진행 정도와 붉은색 형광 발생의 관련성을 확인하기 위해서는 향후 발치된 치아를 사용하여 조직학적 검사를 병행한 추가적인 연구가 필요할 것으로 생각된다. 본 연구 결과 $Qraypen^{TM}$은 유구치의 육안으로 보이지 않은 인접면 우식증을 탐지하는 데 도움을 줄 수 있는 유용하고 간편한 보조장비가 될 수 있을 것으로 기대된다.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.323-334
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• 1988

The purpose of this study was to observe the effect of dentin surface conditioners on the dentin surfaces. Freshly extracted human molars were used in this study. They were stored at $4^{\circ}C$ saline solution before experiment. The crown portions of the teeth were cut in various directions by means of wet diamond point to expose dentin which include transverse, vertical oblique, horizontal and oblique cut to the long axis (Fig. 1). Each tooth was then mounted with self curing acrylic resin in brass ring to expose the flattened dentin surfaces. Final finish was accomplished by grinding the dentin specimens with wet No. 180 and No. 600 grit silicon carbide abrasive paper until a 6.0mm in diameter on a dentin surface was exposed without pulp exposure. The specimens were divided into 9 groups according to the modes of dentin treatment procedure. The following surface treatments were applied on these preparation surfaces; Group 1: unetched (control group) after finish with No. 600 silicon carbide abrasive paper. Group 2: etched with 30% phosphoric acid for 60s Group 3: etched with 10-3 solution for 60s Group 4: Cleaned with 5% NaOCl for 30s Group 5: applied Dentin Adhesit Group 6: cleaned with 5% NaOCl followed by applying the Dentin Adhesit$^{(R)}$ Group 7: applied Photo Bond on the unetched dentin followed by applying the Photo Clearfil Bright Group 8: Etched with 30% phosphoric acid followed by applying Photo Bond and Photo Clearfil Bright Group 9: etched with 10-3 solution followed by applying Photo Bond and Photo Clearfil Bright All the specimens were stored in $37^{\circ}C$ under 50% relative humidity for 24 hours before observations. The specimens in 7, 8, and 9 group, omitting the group 1 to 6, were demineralized in 10% HCl for 10s in order to observe the resin tags. All the specimens in each group were then dried at room temperature. The dried specimens were ion coated with Eiko ion coater (Eiko-engineering Co.), and observed in Hitachi S-430 Scanning electron microscope (Hitachi, Co. Tokyo) at 15KV. The following results were obtained as follows; 1. The smear layers were still remained in group 1,2,4,5, and 6. 2. There is no effect of 5% NaOCl and 30% phosphoric acid on the changes of dentin morphology 3. The dentin treated with 10-3 solution, indicating the tubules opened when the smear layer and the dental plug dissolved. 4. In case of applying the bonding agents the resin tag was not formed at the deep area of dentinal tubules, but in case of applying the Dentin Adhesit$^{(R)}$ that was not.

• Restorative Dentistry and Endodontics
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• 제30권5호
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• pp.372-384
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• 2005

이 연구에서는 Prevotella nigrescens (P. nigrescens)의 lipopolysaccharide (LPS)로 자극한 치주인대 섬유아세포에서 matrix metalloproteinase (MMP)와 tissue inhibitor of metalloproteinase (TIMP)의 생성 양상과, LPS를 수산화칼슘으로 처리했을 때의 영향을 평가하였다. P. nigrescens에서 추출, 정제한 여러 농도의 LPS와 수산화칼슘으로 처리한 LPS로 치주인대 섬유아세포를 자극하여, Immunoprecipitation법으로 MMP-1, -2, TIMP-1의 단백질 생성 양상을, real-time polymerase chain reaction법으로 MMP-1의 mRNA 발현 양상을 분석하였다. 이 연구의 결과는 아래와 같다. 1. MMP-1은 단백질과 유전자 수준 모두 자극 시간과 비례하여 증가하여 48시간에 최대값을 보였다. 2. MMP-2단백질 생성은 1, 10 mg/ml에서 자극 시간과 비례하여 증가하였다. 3. TIMP-1 단백질 생성은 24시간까지 증가하다가 48시간에 감소하였고, 0.1과 1 ${\mg}g/ml$에서 증가하였으나 10 ${\mu}g/ml$ 에서 억제되었다. 4. P. nigrescens의 LPS를 수산화칼슘으로 처리시 MMP-1의 mRNA 발현은 현저하게 감소하였다.

• 대한치과마취과학회지
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• 제6권2호
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• pp.103-112
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• 2006

Background: The purpose of this study was to compare the clinical safety and effect with and without additional submucosal midazolam to oral chloral hydrate and hydroxyzine when used for pediatric conscious sedation in a clinical dental environment. Methods: Thirty one cases of pediatric conscious sedations were performed in this study. Selection criteria included good health (ASA I), under 6 years old, 20 kg of body weight, uncooperative behavior and the need for sedation to receive dental treatment including anesthesia and restorative or surgical procedure for at least two teeth. In each visit, patients were randomly assigned into one of two groups; CH group: chloral hydrate (60 mg/kg), hydroxyzine (1 mg/kg), CH-M group: chloral hydrate (60 mg/kg). hydroxyzine (1 mg/kg) and submucoal midazolam (0.1 mg/kg). 50% nitrous oxide-oxygen was maintained during the sedation period Sedations were monitored using a pulse oximeter for estimating pulse rate (PR) and percutaneous oxygen saturation ($SpO_2$). Behavior response rated using Houpt's scale and need of restraint was assessed every 2 minutes through 30 minutes of operative procedure reviewing the videotape recording. Evaluation of overall behavior success was performed using modified overall behavior rate of Houpt's scale. Data was analyzed using t-test. Results: PR and $SpO_2$ for both groups remained within the normal values. The mean scores for sleep and movement of CH-M group were higher than those of CH group (P < 0.05). There were no significant difference in mean score for crying between two groups. The mean scores of overall behavior of CH-M group was higher than those of CH group (P < 0.01). Reinstraint of CH-M group was less required than that of CH group (P < 0.05). Conclusions: Oral chloral hydrate (60 mg/kg) and hydroxyzine (1 mg/kg) combined with submucosal injection of midazolam was safer and showed more improved sedation effect than oral chloral hydrate (60 mg/kg) and hydroxyzine (1 mg/kg) without midazolam for sedation of pediatric dental patients.

• 대한치과교정학회지
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• 제41권5호
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• pp.354-360
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• 2011

Objective: To investigate the effects of different pilot-drilling methods on the biomechanical stability of self-tapping mini-implant systems at the time of placement in and removal from artificial bone blocks. Methods: Two types of artificial bone blocks (2-mm and 4-mm, 102-pounds per cubic foot [102-PCF] polyurethane foam layered over 100-mm, 40-PCF polyurethane foam) were custom-fabricated. Eight mini-implants were placed using the conventional motor-driven pilot-drilling method and another 8 mini-implants were placed using a novel manual pilot-drilling method (using a manual drill) within each of the 2-mm and 4-mm layered blocks. The maximum torque values at insertion and removal of the mini-implants were measured, and the total energy was calculated. The data were statistically analyzed using linear regression analysis. Results: The maximum insertion torque was similar regardless of block thickness or pilot-drilling method. Regardless of the pilot-drilling method, the maximum removal torque for the 4-mm block was statistically higher than that for the 2-mm block. For a given block, the total energy at both insertion and removal of the mini-implant for the manual pilot-drilling method were statistically higher than those for the motor-driven pilot-drilling method. Further, the total energies at removal for the 2-mm block was higher than that for the 4-mm block, but the energies at insertion were not influenced by the type of bone blocks. Conclusions: During the insertion and removal of mini-implants in artificial bone blocks, the effect of the manual pilot-drilling method on energy usage was similar to that of the conventional, motor-driven pilot-drilling method.

• 구강회복응용과학지
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• 제16권3호
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• pp.221-227
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• 2000

Provisional fixed partial dentures(FPDs) are an important part of many prosthodontic treatment procedures. These provisional fixed prostheses must fulfill biologic, mechanical, and esthetic requirements to be considered successful. Consideration of all these factors and requirements are important because provisional resin restorations may be worn over a long period to assess the results of periodontal and endodontics therapies, and also during the restorative phase of implant reconstructive procedures. This in vitro study examined flexual strength of four resins commonly used for fixed provisional prostheses. The effects of polymerization conditions were also evaluated. The four resins tested were : Caulk Temporary bridge resin(L.D. Caulk Co. Dentsply International Millford), Jet(Lang Dental Mfg. Co. Chicago. ILL. U.S.A), Alike (Coe Laboratories. Inc. Chicago. ILL. U.S.A) and Tokuso Curefast (Coe Laboratories. Inc. Chicago. ILL. U.S.A) The test specimens were 65mm long, 14mm wide, and 3.5mm thickness. 10 specimens of four resins were cured for 15 minutes at atmospheric pressure and 10 specimens of four resins were cured at an additional pressure of approximately 20 psi. A total of 80 specimens were prepared. The flexual strength was determined by three-point bending test. Data were analysed with the Paired samples T-test and Tukey student-range test Within the limitations imposed in this study, the following conclusions can be drawn : 1. Under the condition of bench curing, Caulk Temporary bridge resin showed the highest flexual strength. In decreasing order, the flexual strength of the other materials was as follows : Jet, Tokuso Curefast, Alike, and Caulk Temporary bridge resin demonstrated significantly higher strength than other resins. 2. Under the condition of pressure curing, Jet showed the highest flexual strength. In decreasing order, the flexual strength of the other materials was as follows : Caulk Temporary bridge resin, Tokuso Curefast, and Alike. There were all statistically significant differences among four resins 3. There was a statistically significant difference between bench- and pressure-cured specimens in all four materials.

• 생명과학회지
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• 제24권9호
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• pp.1001-1005
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• 2014

Ginsenoside Rg3는 홍삼으로부터 추출한 활성 성분들 중 하나로 한방 의학에선 원기를 회복시키는 약제로 잘 알려져 있는 인체에 유효한 화학 성분이다. Rg3는 지금까지 많은 연구들에 의하여 다양한 암세포로부터 강력한 항암효과를 가진다고 알려져 있다. 그러나 Rg3가 악성 흑색종 세포에서 어떻게 세포사멸을 유도하는지에 대한 작용 기작은 명백하게 밝혀지지 않았다. 따라서, 본 연구에서는 ginsenoside Rg3가 B16F10 흑색종 세포에서 세포 사멸 유도 활성 및 기전에 관한 영향을 조사하였다. 세포 생존력을 MTT assay 법으로 수행한 결과, B16F10 세포에선 농도 의존적으로 세포증식 저해 효과가 나타났고 정상세포인 EA.hy.926 과 NIH3T3 에서는 나타나지 않았다. B1610 세포에 Rg3를 농도 별로 처리 후, TUNEL 염색을 한 결과 세포사멸이 농도 의존적으로 증가 하는 것을 확인 할 수 있었다. Western blot 분석을 실시한 결과, Rg3를 처리한 B16F10 세포에서 p-FAK, Bcl-2, pro-caspase3 단백질들의 발현이 감소 되었고 이와 반대로 Bax, p-p38의 발현은 증가되었다. 따라서, 본 연구에서는 Rg3가 B16F10 흑색종 세포에서 항암제의 agent로써 사용 될 수 있다는 것을 입증하였다.

• Restorative Dentistry and Endodontics
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• 제34권2호
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• pp.137-144
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• 2009

본 연구는 한국인의 하악 제1 대구치 60개를 대상으로 생리적 근단공의 크기와 형태, 근심 치근의 치근단 3mm에서 isthmus의 발생 빈도와 형태, 그리고 원심 치근의 치근단 3mm의 근관 형태를 입체현미경하에서 60배로 조사한 결과 다음과 같은 결론을 얻었다. 1.근심 치근은 두 개의 근단공을 가지는 비율이 높았으며(51.67%), 원심 치근은 하나의 근단공을 가지는 비율이 높았다(71.66%). 2. 부근단공의 빈도는 근심 치근의 1개의 근단공을 가지는 경우가 가장 높았다(26.07%) 3. 생리적 근단공의 크기는 근심 치근에서 하나의 근단공을 가지는 경우 0.329mm, 근심 협측 근단공은 0.266mm, 근심 설측 근단공은 0.246mm였으며, 원심 치근에서 하나의 근단공을 가지는 경우 0.375mm, 원심 협측 근단공은 0.291mm, 원심 설측 근단공은 0.237mm로 나타났다. 4. 근단공의 형태는 oval 형태 (69.93%)가 가장 많았다. 5.근심 치근의 치근단 3mm에서 isthmus의 발생빈도는 55%였으며, partial isthmus는 31.66%, complete isth-mus는 23.34%로 나타났다. 6.원심 치근의 치근단 3mm의 근관 형태는 oval형태(50.64%)가 가장 많았다. 이상의 연구 결과 하악 제1대구치의 성공적인 근관 치료를 위해서는 생리적 근단공의 실제 크기와 형태 및 isthmus의 존재에 대한사전 지식이 필요할 것이다.

• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.25.1-25.10
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• 2018

Objectives: To evaluate the mechanical properties and metallurgical characteristics of the M3 Rotary and M3 Pro Gold files (United Dental). Materials and Methods: One hundred and sixty new M3 Rotary and M3 Pro Gold files (sizes 20/0.04 and 25/0.04) were used. Torque and angle of rotation at failure (n = 20) were measured according to ISO 3630-1. Cyclic fatigue resistance was tested by measuring the number of cycles to failure in an artificial stainless steel canal ($60^{\circ}$ angle of curvature and a 5-mm radius). The metallurgical characteristics were investigated by differential scanning calorimetry. Data were analyzed using analysis of variance and the Student-Newman-Keuls test. Results: Comparing the same size of the 2 different instruments, cyclic fatigue resistance was significantly higher in the M3 Pro Gold files than in the M3 Rotary files (p < 0.001). No significant difference was observed between the files in the maximum torque load, while a significantly higher angular rotation to fracture was observed for M3 Pro Gold (p < 0.05). In the DSC analysis, the M3 Pro Gold files showed one prominent peak on the heating curve and 2 prominent peaks on the cooling curve. In contrast, the M3 Rotary files showed 1 small peak on the heating curve and 1 small peak on the cooling curve. Conclusions: The M3 Pro Gold files showed greater flexibility and angular rotation than the M3 Rotary files, without decrement of their torque resistance. The superior flexibility of M3 Pro Gold files can be attributed to their martensite phase.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.378-384
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• 2003

This study evaluated the influence of a desensitizer(MS coat) on microtensile bond strength of different adhesives:a three-step adhesive(All-Bond 2), a two-step adhesive(Single Bond), a one-step adhesive(One-up Bond F). Non-caries extracted human molars were used. Dentin surface was obtained by horizontal section on mid-portion of crown using a water-cooled low speed diamond saw. Teeth were randomly divided into 6 group. AMO(MS coat + All Bond), SMO(MS coat + Single Bond)- and OMO(MS coat + One-up Bond F)-dentin surface were treated with 17% EDTA before bonded adhesive. AMX-, SMX- and OMX-dentin surface were bonded with All-Bond 2, Single Bond and One-up Bond F, respectively. with no previous treatment with MS coat and 17% EDTA. About 1cm high resin composite($Z-250^{TM}$) were incrementally build-up on the treated surface. The specimens for the microtensile test were serially sectioned perpendicular to the adhesive layer to obtain $0.7{\times}0.7mm$ sticks. 30 sticks were prepared from each group. After that. tensile bond strength for each stick was measured with Microtensile Tester at a 1mm/min crosshead speed. Fractured dentin surfaces were observed under the SEM. The results were statistically analysed by using a One-way ANOVA and Tukey's test(p<0.05). Value in MPa were: $AMO-44.35{\pm}13.21;{\;}SMO-39.35{\pm}13.32;{\;}OMO-31.07{\pm}10.25;{\;}AMX-49.22{\pm}16.38;{\;}SMX-56.02{\pm}13.35;{\;}OMX-72.93{\pm}16.19$. Application of MS coat reduced microtensile bond strengths of both Single Bond and One-up Bond F, whereas microtensile bond strengths of All-Bond 2 were not affected significantly.