• 대한치과보철학회지
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• 제36권4호
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• pp.549-565
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• 1998

Porcelain is considered to be one of the materials of choice for restoration where esthetics is of concern. But porcelain surface without final glazing treatment may induce undesirable results such as inflammatory response on adjacent soft tissues due to plaque accumulation and increased wear of opposing teeth. Therefore, rough porcelain surface must be smoothened by final glazing treatment or chairside polishing procedure. The purpose of this study was to compare the surface roughness among self-glazed, overglazed and polished porcelain with various polishing kit, and to detect which phase of polishing is optimal in clinic. Specimens were fabricated with Vita VMK porcelain. The surface treatment of each group was performed as follows. Group 1 : overglazing treatment Group 2 : self-glazing treatment Group 3 : polishing with the Truluster Polishing System for Porcelain(Brasseler, U.S.A.) Group 4 : polishing with the Exa Cerapol Adjustment kit (Edenta dental products, Switzerland) followed by finishing with diamond-filled polishing paste Group 5 : polishing with the Shofu Porcelain Adjustment kit (Shofu inc., Japan) followed by finishing with diamond-filled polishing paste. At each polishing steps, the measurement of Ra and Rq values were performed, and the surface was examined by scanning electron microscope. The results were as follows : 1. Overglazing treatment brought smoother surface than self-glazing treatment. 2. Polishing systems without porcelain polishing paste did not make better result than self-glazing treatment. 3. Polishing system with porcelain polishing paste made similar result to overglazing treatment. 4. Applying diamond-filled polishing paste after using polishing system which has no porcelain polishing paste produced surface as smooth as overglazing treatment does.

• 대한치과보철학회지
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• 제39권2호
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• pp.208-219
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• 2001

To study the effect of dentin permeability on a tooth with wear from tooth brushing after application of desensitizing agent, extracted teeth free from caries were chosen. Coronal dentin discs with thickness of 1mm were prepared. Using the split chamber device developed by Pashely, hydraulic conductance, scanning electron microscope images(SEM) and atomic force microscope images(AFM) were compared and contrasted before and immediately after the application of desensitizing agent and after equivalent tooth brushing of 1 week, 2 weeks, and 6 weeks. Four commercially available desensitizing agents were used in this study ; they were Gluma, Seal & Protect, All-Bond 2 and MS Coat. The results of this study are as follows. 1. On all specimens, the hydraulic conductance decreased after the application of tooth desensitizing agent. 2. Except the specimens treated with MS Coat, the remaining specimens had an increase in dentin permeability after tooth brushing for 1 and 2 weeks but a decrease after 6 weeks. 3. The specimens treated with MS Coat had statistically significant increase in the dentin permeability regardless with the duration of tooth brushing. 4. On examination of SEM and AFM, the dentinal tubule diameter had decreased after treatment of desensitizing agents. The specimens other than those treated with MS Coat, smear layers were noted after tooth brushing. It is not always consistant but the hydraulic conductance correlated with the images from SEM and AFM.

• 대한치과보철학회지
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• 제55권2호
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• pp.187-197
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• 2017

과도한 수직피개를 가진 과개교합 환자에서 안정적인 유지접촉이 없는 경우 연조직 외상, 치질 파괴, 대합치 정출의 문제가 일어날 수 있고 이는 결과적으로 교합평면의 붕괴와 기능적, 심미적 문제로 이어진다. 치아의 상실과 마모가 발생된 환자에 대한 치료계획 수립 시 올바른 교합수직고경 설정을 통해 환자의 안정적인 악간관계를 회복시켜야 한다. 본 증례는 중심위에서 극심한 면 대 면 접촉이 발생된, 편측 구치부가 상실된 과개교합 환자에게 수직고경 증가를 동반한 완전구강회복술을 시행한 증례를 보고하였다. 보철수복 공간 확보를 위해 수직고경증가를 동반한 완전구강회복술로 안정적인 교합관계와 조화로운 전방, 측방유도를 얻어 환자의 기능적, 심미적 문제를 해결할 수 있었다.

• 대한치과보철학회지
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• 제56권4호
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• pp.347-353
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• 2018

치아의 마모는 나이가 들어감에 따라 진행되는 정상적인 과정이지만, 과도한 마모는 교합 부조화, 기능 및 심미적인 문제를 가져온다. 특히, 구치부 지지가 상실된 경우 전치부 치아의 마모와 수직 고경의 감소가 발생할 수 있고 이로 인하여 측두 하악 관절 장애 및 비심미적인 안모 변화, 저작 효율 감소가 일어날 수 있다. 본 증례의 환자는 70세 남자 환자로 심한 치아의 마모로 인한 수직 고경 상실로 심미적인 회복을 위해 내원하였으며 구강 검사, 방사선 검사, 진단 모형 검사를 통해 수직 고경을 평가하고, 수직 고경 증가를 동반한 가철성 국소의치로 수복을 결정하였다. 10개월 간의 관찰 결과 안정적으로 교합이 유지되고 있는 것을 확인하였고, 환자의 기능적, 심미적인 만족을 얻었다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권3호
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• pp.211-216
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• 2015

차체중량이 90 ton인 초대형 유압굴삭기에서는 유압시스템의 효율향상을 통한 연비개선을 위해서 유압펌프 구동용 기어박스(hydraulic pump driving gear box)를 사용하여 다수(3~6개)의 펌프를 병렬로 장착하여 사용한다. 펌프 구동 기어 박스는 굴삭기의 대형엔진과 연결되는 입력 축 1개로 기계적 동력인 회전수와 토크를 공급받아 고압펌프와 저압펌프에서로 다른 기계적 출력을 공급하게 된다. 따라서 펌프 구동 기어박스는 굴삭기의 대동맥과 같으며, 엔진이 가동되는 시간동안 지속적으로 펌프를 구동함으로서 장 수명이 요구된다. 본 연구에서는 큰 시험동력(600kw)이 요구되는 수명평가에서 에너지절감을 위한 전기 회생식 시험 장비를 구축하여 높은 에너지 절감과 수명시험을 수행하면서 기어박스의 마모 특성을 분석하는 방법으로 윤활유 오염 입자 분석과 기어파손 유무를 검증하는 방법으로 진동분석 방법을 사용하였다.

• 구강회복응용과학지
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• 제21권1호
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• pp.69-81
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• 2005

The objective of this study was to evaluate the toothbrush abrasion characteristics of class V restorations. Thirty extracted human premolars, which were collected from oral surgery clinics were used. We mounted five teeth in a metal ring mold of 50 mm in diameter and 15 mm in height using chemically cured acrylic resin. Class V cavities were prepared in lingual cervical root surfaces and restored using one of following restorative materials : Dentin Conditioner/Fuji II LC (Group FL), All Bond II/Z-250 (Group ZT), One-up Bond F/Palfigue Estelite (Group PE), F2000 Primer/Adhesive (Group FT), and Prime & Bond 2.1/Dyract AP (Group DR). They were stored under distilled water at $37^{\circ}C$ for seven days. The toothbrush abrasion test was conducted using a wear testing machine of pin-on disk type under a load of 1.5 N for 100,000 cycles. We have examined the bonded interfaces, the changes of surface roughness and color of abraded surfaces. From this experiment, the following results were obtained. 1. The change of surface roughness showed high degree: RMGIC>compomer>composite resin (p<0.05). 2. Because of the protrusion and missing of filler particles, SEM observation of abraded surfaces of RMGIC and compomers revealed the increase of surface roughness due to the selective removal of matrix resin. 3. The color change by toothbrush abrasion was affected in large part by the change of $L^*$ and $b^*$ of resin composites (p<0.05). 4. The color change by toothbrush abrasion was so small to detect by human eyes. 5. SEM observation of abraded surfaces revealed the interface bonding was the best in the FT group.

• 대한소아치과학회지
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• 제30권1호
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• pp.110-115
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• 2003

치외치(Dens evaginatus)는 조직 형태 분화기에 법랑기의 내측 법랑 상피가 외부로 과증식 되거나 치수 간엽 조직 이 국소적으로 과증식되어 나타난다. 치외치는 하악제 2소구치에서 가장 빈발하며 유전적 성향을 가지고 있다고 알려져 있다. 치아에 발생한 결절은 법랑질, 상아질, 치수 등의 정상 치아구조를 가지고 있으며 그 형태학적 특성으로 인해 저작에 의한 파절 또는 마모가 발생하여 미세한 치수노출이 발생할 수 있다. 이러한 치수노출에 의해서 치수염증, 치근단 병변, 치근 형성 중지 등이 생길 수 있으므로 조기에 발견하여 예방 및 조기치료를 시행하는 것이 중요하다. 만약 이미 감염이 진행되어 치근단 병변이 야기된 경우 적절한 근관 치료가 행해져야 하며 미완성 치근을 가지고 있는 경우가 대부분이므로 치근단 형성술을 병행해야 한다. 이에 저자는 치외치에 의한 치근단 병변을 주소로 내원하여 치근단 형성술을 시행한 언니의 증례와, 함께 내원하여 사전에 발견하고 점진적 삭제술을 시행하여 양호한 결과를 얻은 동생의 증례를 보고하는 바이다.

• 대한치과보철학회지
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• 제52권1호
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• pp.42-47
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• 2014

광범위한 치아 상실과 마모로 인한 교합면의 파괴로 수직고경이 감소된 경우 안모의 변화, 전방 유도의 상실로 인한 반대 교합을 보일 수 있으며, 또한 턱관절의 문제를 발생 시킬 수도 있다. 이러한 경우 교합 수직 고경의 증가를 통한 전악 수복을 고려할 수 있으며, 적절한 환자의 수직 고경 평가가 필요하다. 본 증례는 80세의 남자 환자로 전반적인 보철계획을 주소로 내원하였으며, 치아상실 및 마모에 따른 전치부의 반대 교합과 교합 수직 고경의 감소가 관찰되었다. 진단 모형과 방사선 사진, 임상적 검사를 이용하여 교합 관계를 분석하여 교합 수직 고경 증가를 결정하였다. 진단 wax up을 시행하였고 임시 보철물을 제작하였다. 3개월의 적응 기간 후 상악 고정성 보철물과 하악 임플란트 지지 피개의치로 최종 수복하였다. 장착 후 8개월경과 관찰 중이며 양호한 심미적 기능적 개선을 보였다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.157-157
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• 2017

Titanium and its alloys that have a good biocompatibility, corrosion resistance, and mechanical properties such as hardness and wear resistance are widely used in dental and orthopedic implant applications. They can directly connect to bone. However, they do not form a chemical bond with bone tissue. Plasma electrolytic oxidation (PEO) that combines the high voltage spark and electrochemical oxidation is a novel method to form ceramic coatings on light metals such as titanium and its alloys. This is an excellent reproducibility and economical, because the size and shape control of the nano-structure is relatively easy. Silicon (Si), manganese (Mn), and magnesium (Mg) has a useful to bone. Particularly, Si has been found to be essential for normal bone, cartilage growth and development. Manganese influences regulation of bone remodeling because its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. Insufficience of Mn in human body is probably contributing cause of osteoporosis. Pre-studies have shown that Mg plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. The objective of this work was to study nucleation and growth of bone-like apatite formation on Ti-6Al-4V in solution containing Mn, Mg, and Si ions after plasma electrolytic oxidation. Anodized alloys was prepared at 270V~300V voltages. And bone-like apatite formation was carried out in SBF solution for 1, 3, 5, and 7 days. The morphologies of PEO-treated Ti-6Al-4V alloy in containing Mn, Mg, and Si ions were examined by FE-SEM, EDS, and XRD.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.80-80
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• 2017

Titanium and its alloys that have a good biocompatibility, corrosion resistance, and mechanical properties such as hardness and wear resistance are widely used in dental and orthopedic implant applications. However, they do not form a chemical bond with bone tissue. Plasma electrolytic oxidation (PEO) that combines the high voltage spark and electro-chemical oxidation is a novel method to form ceramic coatings on light metals such as tita-nium and its alloys. This is an excellent re-producibility and economical, because the size and shape control of the nano-structure is relatively easy. Silicon (Si), manganese (Mn), and magne-sium (Mg) have a useful to bone. Particularly, Si has been found to be essential for normal bone, cartilage growth, and development. Mn influences regulation of bone remodeling be-cause its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. Pre-studies have shown that Mg plays very im-portant roles in essential for normal growth and metabolism of skeletal tissue in verte-brates and can be detected as minor constitu-ents in teeth and bone. In this study, Electrochemical behavior of plasma electrolytic oxidized films formed in solution containing Mn, Mg and Si ions were researched using various experimental in-struments. A series of Si-Mn-Mg coatings are produced on Ti dental implant using PEO, with the substitution degree, respectively, at 5 and 10%. The potentiodynamic polarization and AC impedance tests for corrosion behav-iors were carried out in 0.9% NaCl solution at similar body temperature using a potentiostat with a scan rate of 1.67mV/s and potential range from -1500mV to + 2000mV. Also, AC impedance was performed at frequencies anging from 10MHz to 100kHz for corrosion resistance.