• 한국재료학회지
• /
• 제15권9호
• /
• pp.585-588
• /
• 2005

Titanium and Titanium alloys are widely used as an orthopedic and dental implant material because of their excellent biocompatibility and mechanical strength. In this study, ECAP Cp-Ti and Cp-Ti were heat treated for different annealing time of 30 min, 90 min and 3 hours. The grain size for each condition was studied. The micro-Vicker hardness test was carried out f3r each different heat treated samples. The micro-Vicker hardness test for ECAP Cp-Ti, Cp-Ti and Cp-Ti (3hr) revealed hardness values of 239.5, 182 and 144 Hv, respectively. The grain size was increased from approximately $70{\mu}m\;to\;300{\mu}m$ with the increase in heat treatment time from 30 min to 3 hours. The heat treated samples were tested for their biocompatibility in simulated body fluid (SBF) and corrosion rates was determined using Polarization Curve test (PCT). The PCT results showed Cp-Ti with comparatively high corrosion potential of -0.18 V and corresponding corrosion current of $2\times10^{-6}$ A, while the corrosion rate in ECAP Cp-Ti and Cp-Ti (30 min annealed) showed very similar results of corrosion potential about -0.47 V with corresponding corrosion current of $7\times10^{-8}$ A.

• 치위생과학회지
• /
• 제9권2호
• /
• pp.153-160
• /
• 2009

본 연구는 금속-도재 수복물 제작에 사용되는 Ni-Cr alloy와 Co-Cr alloy, 그리고 티타늄에 gold bonding agent를 도포하여 Au coating 층을 형성하였다. 각 시편의 절단면을 전자현미경으로 Au coating 층과 porcelain bonder, 그리고 불투명 도재간의 결합을 관찰하였고, 각 계면의 상태를 SEM/EDS 방법으로 조사하였다. 실험에서 사용된 재료와 방법의 범위 내에서 다음과 같은 결론을 얻었다. 1. Gold bonding agent를 사용하여 형성한 Au coating 층은 미세다공성을 가진 구조로 판단되었다. 2. Au coating 층과 porcelain bonder 그리고 불투명 도재간의 결합은 잘 일어나 보였다. 3. Au coating 층은 도재 소성과정에서 발생하는 산화층의 확산을 제한하는 것으로 관찰되었다.

• 융합정보논문지
• /
• 제8권6호
• /
• pp.21-29
• /
• 2018

융복합시대에 생활스트레스가 대학생활만족도와 전공만족도에 미치는 영향에 대하여 파악하고자 한다. 전라도와 광주광역시에 위치한 대학교의 재학생 364명 대상으로 2018년 4월 2일부터 2018년 4월 23일까지 자기기입식 설문조사를 실시하였다. 일반적 특성에 따른 대학생활 만족도와 전공만족도는 주관적 건강상태의 경우 양호가 가장 높게 나타났다. 생활스트레스 중 대인관계 영역 중에서는 교수관계가 높게 나타났고, 당면과제 영역 중에서는 학업문제가 가장 높게 나타났다. 생활스트레스 전체는 평소 수면시간의 경우 6-8시간이 가장 낮게 나타났다. 대학생활 만족도에 가장 많은 영향을 미치는 요인은 전공만족도 이였다. 전공만족도에 가장 많은 영향을 미치는 요인은 대학생활 만족도이었고, 생활스트레스 정도가 높을수록 전공만족도가 낮게 나타났다. 따라서 대학생들의 생활스트레스 완화될 수 있는 교육 및 프로그램 개발에 기초자료로 활용하고자한다.

• The Journal of Advanced Prosthodontics
• /
• 제11권3호
• /
• pp.162-168
• /
• 2019

PURPOSE. The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel. MATERIALS AND METHODS. Twenty-five Y-TZP slabs from each brand (Lava, 3M and Bruxzir, Glidewell Laboratories) with different surface conditions (Control polished - CPZ; Polished/ground - GRZ; Polished/ground/repolished - RPZ; Glazed - GZ; Porcelain-veneered - PVZ; n=5) were abraded (500,000 cycles, 80 N) against artificial enamel (6 mm diameter steatite). Y-TZP roughness (in ${\mu}m$) before and after chewing simulation (CS) and antagonist steatite volume loss (in $mm^3$) were evaluated using a contact surface profilometer. Y-TZP roughness was analyzed by three-way analysis of variance (ANOVA) and steatite wear by two-way ANOVA and Tukey Honest Difference (HSD) (P=.05). RESULTS. There was no effect of Y-TZP brand on surface roughness (P=.216) and steatite loss (P=.064). A significant interaction effect (P<.001) between surface condition and CS on Y-TZP roughness was observed. GZ specimens showed higher roughness after CS (before CS - $3.7{\pm}1.8{\mu}m$; after CS - $13.54{\pm}3.11{\mu}m$), with partial removal of the glaze layer. Indenters abraded against CPZ ($0.09{\pm}0.03mm^3$) were worn more than those abraded against PVZ ($0.02{\pm}0.01mm^3$) and GZ ($0.02{\pm}0.01mm^3$). Higher wear caused by direct abrasion against zirconia was confirmed by SEM. CONCLUSION. Polishing with an intraoral polishing system did not reduce the roughness of zirconia. Wear of the opposing artificial enamel was affected by the material on the surface rather than the finishing technique applied, indicating that polished zirconia is more deleterious to artificial enamel than are glazed and porcelain-veneered restorations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제47권1호
• /
• pp.20-24
• /
• 2021

Objectives: The aim of this study was to evaluate the profile of patients on antiresorptive therapies for cancer treatment and assess presence of oral lesions, oral hygiene status, and knowledge regarding medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: This was an observational cross-sectional study that evaluated patients treated with antiresorptive medication at a single cancer hospital. Clinical data were collected and oral examination was performed to assess patient oral health. Results: From July 2017 to December 2018, 90 patients were assessed; 64 were female and 26 were male, and the mean age was 61 years. The most common drug was an intravenous bisphosphonate, zoledronic acid. Among the 90 patients, 47 presented with some type of oral disease, isolated or associated. Among these 47 patients, 9 patients (10%) developed osteonecrosis. Oral hygiene was evaluated, and most patients, with or without MRONJ, presented with regular to poor condition. Regarding patient knowledge of the risks of MRONJ and the risks associated with dental surgery, 60% stated that they were not aware of the risks. Conclusion: Identifying the profile of patients and their needs facilitates not only the preventive process, but also the emergence of new therapeutic options. Our study shows that most patients are weakened both by metastatic disease and antineoplastic treatment as well as by issues associated with aging because most were over 60 years of age. Collectively, this information should be considered for management of preventive and therapeutic measures.

• 한국방사선학회논문지
• /
• 제8권7호
• /
• pp.467-477
• /
• 2014

본 연구의 목적은 교육용 치과 엑스선 발생장치를 설치 및 가동 중인 전국 치위생(학)과를 대상으로 방사선 작업종사자의 방사선 안전 관리 실태를 설문 조사하고 이를 체계적으로 추이 분석하여 교육용 치과 엑스선 발생장치의 안전한 이용 기반을 확립하기 위한 기초 자료로 제공하고자 하였다. 이를 위하여 교육용 치과 엑스선 발생장치의 방사선 안전 관리와 관계되는 원자력 관계 법령 및 국내 방사선 안전성 평가 및 규제 기술 개발 현황에 대한 용역 보고서를 참고하여 포괄적인 문헌 조사를 하였으며 이를 토대로 응답자의 일반적 특성, 방사선안전관리자의 위상, 방사선 안전관리 현황과 지식 및 의식 수준에 대한 설문지를 작성하였다. 본 연구는 국내 교육기관 내 방사선안전관리자와 교육용 치과 엑스선 발생장치를 운전 가능한 학사 및 실습 조교, 전임 교원 224명을 대상으로 설문 조사를 시행하여 설문 응답 누락 및 불충분한 응답을 제외한 95부를 회수하여 분석 자료로 이용하였다. 분석 방법은 일반적 특성 및 방사선안전관리자의 위상은 빈도와 백분율을 구하였으며 방사선 안전 관리 현황과 지식 및 의식 수준은 빈도 분석과 설문 문항별 연관성 분석을 위한 ${\chi}^2$ 검정(chi-square test)과 수준간 연관성을 구하기 위한 피어슨 상관분석(Pearson correlation analysis)을 하였다. 결과적으로 교육용 치과 엑스선 발생장치의 운영은 대부분 대학 이상의 사회적 교육 수준이 높고 치위생학을 전공한 20대에서 40대의 여성이 담당하고 있었으며 남성과 비교하여 방사선 안전 관리에 대한 의식 수준이 높게 나타났으며 통계적으로 유의한 선형적 관계를 보였다(${\chi}^2$ >5, 0.1${\chi}^2$ >5, 0.3${\chi}^2$ >5, 0.3

• 치위생과학회지
• /
• 제5권4호
• /
• pp.245-250
• /
• 2005

본 연구는 대구시 북구에 소재한 복현 초등학교 1,2학년들과 복현초등학교 1,2학년 학생들의 어머니들을 대상으로 2005년 6월 1일부터 2005년 6월 30일 까지 1학년 82명과 2학년 192명중에서 남학생 135명, 여학생 140명으로 총 275명을 대상으로 스스로 답변을 기재하는 자기 기입 방식으로 설문지를 작성케 하여 수합하였다. 설문지에 응답한 300명 중 응답내용이 부실한 25명을 제외한 총 275명을 대상으로 하였다. 1. 어머니와 자녀의 구강건강 행위 중에서 어머니의 구강건강행위에서는 하루평균 잇솔질횟수가 3회이상이 68.7%로 2회이하가 31.3%로 어머니의 하루평균 잇솔질횟수는 3회이상이 2회이하 보다 높게 나타났다. 반면에 자녀의 구강건강행위에서는 하루평균 잇솔질횟수가 3회이상이 14.2%로 2회이하가 85.8%로 3회이상 보다 2회이하가 높게 나타났다. 2. 어머니의 불소에 대한 지식수준은 총 7문항중 3-4문항에서 정답으로 응답한 '중'에서 55.3%로 가장 높게 났고, 어머니의 치주질환에 대한 지식수준은 총 7문항중 4-5문항에서 정답으로 응답한 '중'에서 47.3%로 가장 높게 나타났다. 3. 어머니의 구강건강지식 및 행위와 자녀의 칫솔질 횟수와의 관련성에서는 칫솔질 횟수에서만 통계적으로 유의함이 나타났다(p < 0.05) 4. 어머니의 사회인구학적인 요인과 자녀의 칫솔질횟수와의 관련성에서 나이, 교육수준, 월평균소득에서는 통계적으로 유의함이 없었으나, 직업의 유 무에서는 통계적으로 유의함이 나타났다(p < 0.05).

• 대한치과기공학회지
• /
• 제28권1호
• /
• pp.121-142
• /
• 2006

Collecting materials for study on teaching efficiency and satisfaction of clinical training, it changes. Dental technology's educational procedure to many ways of a prospect. In a circumstance that needed higher level of education, this study is aimed on realizing an importance of clinical training through the various materials that previously carried out and offering basic knowledge to take better clinical training for the students. Study results below 1. This Investigation conducted on 123 of sophomores(70.3%) and 52 of juniors(29.7%) who have been taken clinical training, and men's proportion(51.45%)is a bit higher than girls(48.6%). The 64% of respondents taken largest proportion were 20 to 24 years old. As 67.9% of respondents attended daytime school and 30.3% of them attended nighttime one, their school time shows a little difference. In a question about relation ship, one answered "Harmonious" took largest proportion by 72.6% during training, and about the degree of satisfaction of campus life who answered "normal" were the most with 59.4%. 2. About the reason choosing dental technology as a major, 41.1% taken the most answered "due to the specialized job", "Getting job easily" was second with 26.9%, and third was "recommended from around" with 18.3%. 50.3% of the respondents answered "normal" about the Satisfaction of their major, student marked in grade "B" most with 51.4% 3. In a investigation result about clinical training statues and preference, most(72.6%) choose place less than 10 for clinical training, and 60.6% of them resided own home. About their commuting time from home to training place, 44% was under 30min, 40% took time 30-60min. It shows students prefer shotter distance in terms of choosing training place. 4. Each part manager took large proportion as a clinical trainer with 33.7%, Training curriculum reform and developing method were most answer as a improvement measure after completing training with 30%. 5. The average of total score about clinical training was 3.15 of 5. In the detailed question, 'satisfaction of clinical training' got 3.38 as a highest score, the lowest score was 2.86 that is about satisfaction of clinical training period. The average score about efficiency of study was 2.86 and in detailed question, 'a Role model' got 3.26 as a highest score and participation of student got 3.05 as a lowest score. 6. The result of T-test to see the difference of the satisfaction according to the general character and clinic training condition between teaching efficiency is that the degree of satisfaction of clinical training showed statistical significance only in the degree of satisfaction of campus life(p<0.05), and teaching efficiency has a statistical significance with their age, grade, and satisfaction of campus life (p<0.05). 7. The relation between of teaching efficiency of clinical training and satisfaction of clinical training of dental technologic student has a statistical meaning in significance leveler 0.01. Now, therefore we suggest following based on these result. 1. To elevate satisfaction of clinical training, it agentry needs development of consistent clinical training curriculum. 2. To grasp the satisfaction and requirement, in needs to measure anxiousness and satisfactory degree after completing training 3. To train efficiently and evaluate efficiency over the teaching activities, it needs to develop measuring tools for teaching efficiency in terms of teacher's important rules in a clinical training. 4. Strengthen the relations with the study developing and managing curriculum gathering theoretical knowledge and practice. And make an effort to apply to their students. 5. Let the trainee take a class setting a belief, sense of value, function and obtain behavior by making the students comfort over clinical training as increasing teaching efficiency.

• 대한치과교정학회지
• /
• 제27권4호
• /
• pp.661-668
• /
• 1997

치열의 crowding을 해소하는 방법에는 크게 발치, 비발치로 크게 나눌 수 있다. 발치로 교정하는 경우 주로 고려되는 발치대상 치아는 제1, 2 소구치이며 그 다음이 제2 대구치, 하악전치, 제1대구치등 이다. 하악전치의 발치는 소구치 발치가 여의치 않을 때, 선택적으로 사용될 수 있다. case를 잘 선택한다면, 치료시간도 줄일 수 있고, 간편하게, 심미적 및 기능적으로도 좋은 효과를 얻을 수 있다. 아직 이에 대한 국내 연구와 보고가 활발하지 않아 소개하고자 한다.

• 대한소아치과학회지
• /
• 제24권4호
• /
• pp.743-750
• /
• 1997

Gingivitis is the most prevalent type of periodontal disease and the dental plaque is considered as a major contributory factor. As the poor oral hygiene is firmly related to the occurrence of periodontal disease, pediatric dentist should make every effort to promote the oral health and control the plaque effectively for the high risk patients, especially for those who are under orthodontic treatment. P.M.T.C.(Professional Mechanical Tooth Cleaning), introduced by Dr. P. Axelsson in 1969, is a very effective method of plaque removal and can be performed by specially trained personnel. Two pediatric orthodontic patients were treated by P.M.T.C. for the elimination of gingivitis and gingival swelling. Signi ficant improvements of gingival condition were achieved in both cases but additional preventive programs and home care along with professional office care seem to be necessary for the best result.