Shear bond strength of composite resin to high performance polymer PEKK according to surface treatments and bonding materials

이기선,신명식,이정열,류재준,신상완 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.5

PURPOSE. The object of the present study was to evaluate the shear bonding strength of composite to PEKK by applying several methods of surface treatment associated with various bonding materials. MATERIALS AND METHODS. One hundred and fifty PEKK specimens were assigned randomly to fifteen groups (n = 10) with the combination of three different surface treatments (95% sulfuric acid etching, airborne abrasion with 50 μm alumina, and airborne abrasion with 110 μm silica-coating alumina) and five different bonding materials(Luxatemp Glaze & Bond, Visio.link, All-Bond Universal, Single Bond Universal, and Monobond Plus with Heliobond). After surface treatment, surface roughness and contact angles were examined. Topography modifications after surface treatment were assessed with scanning electron microscopy. Resin composite was mounted on each specimen and then subjected to shear bond strength (SBS) test. SBS data were analyzed statistically using two-way ANOVA, and post-hoc Tukey’s test (P<.05). RESULTS. Regardless of bonding materials, mechanical surface treatment groups yielded significantly higher shear bonding strength values than chemical surface treatment groups. Unlike other adhesives, MDP and silane containing self-etching universal adhesive (Single Bond Universal) showed an effective shear bonding strength regardless of surface treatment method. CONCLUSION. Mechanical surface treatment behaves better in terms of PEKK bonding. In addition, self-etching universal adhesive (Single Bond Universal) can be an alternative bonding material to PEKK irrespective of surface treatment method.

이달의 수필 : 카드

이기선 대한지방행정공제회 1968 地方行政 Vol.17 No.182

대광사 미륵대불 조성과 그 신앙

이기선 천태불교문화연구원 2017 天台學硏究 Vol.20 No.-

코로나 시대 이란의 음악교육 체계 변화: 테헤란 여자 음악학교 사례를 근거로

이기선 세계음악학회 2022 음악과 문화 Vol.- No.46

This study is about the history, the major, the curriculum, the current status of education since Covid-19 focusing on Tehran music school(girls branch) located in Teheran, Iran. Since the Islamic Revolution in 1979, Iran has strictly been under control of government regardless of the field of classical, traditional, and popular music. Therefore, music subject was not educated separately in the curriculum of the general elementary, middle, and high schools except for a few private schools, and because of this reason, it is very hard to explore the current status of music education in the public education of Iran. However, students who want to study or to major in music still can enter related music schools to have professional education, so it is still possible to study the current status of music education by it. Tehran music school located in Teheran, the capital of Iran, is a prestigious music school with a history of more than about a century. Since the established in 1914, the name of the school and the curriculum has reorganized. So, now the school is divided and operated into boys and girls separately. Since the spread of Covid-19, Tehran music school(girls branch) has been conducting both face-to-face and non-face-to-face classes, and non-face-to-face classes have been conducted from March 2020 to August 2021, and since September 2021, both face-to-face and non-face-to-face classes have been conducted. The teaching methods of face-to-face and non-face-to-face classes are similar with other music middle and high schools since Covid-19, so it was confirmed that the school follows the global educational trends. Moreover, there were some problems, for example, the use of government-provided “Shad” platforms being not familiar in the early non-face-to-face classes as well as other factors such as slow internet speed and unstable connection, pointed out. Moreover, other major issues, for instance, the lack of infrastructure, the spread of Internet networks, the government’s regulation of Internet speed, the lack of educational restrictions like laptops and mobile phones for students in poor areas, have emerged as well. The changes in the education field because of Covid-19 are still in progress, and this remote education system will continue in the future. Therefore, the efforts of Iranian government for improvement of many problems sincerely need to establish stable Internet infrastructure system, provide an appropriate environment for art education classes, and develop user-friendly educational platforms. This study is meaningful as a basic study because there is no any other research related to music education in Iran and nothing has not been introduced in Korea yet, so based on this study, it hopes to continue discussions on the music environment of Islamic culture countries as well as understanding the current status of music education in Iran. .

다이아몬드 공구용 코발트계 합금 결합제의 제조 및 기계적 성질

이기선,정승부,Lee, Gi-Seon,Jeong, Seung-Bu 한국재료학회 2000 한국재료학회지 Vol.10 No.8

Diamond 공구용 Co-0.5C-(15∼20)Cr-20Ni-8W-(2∼7)Fe 합금 결합제를 볼밍링(ball-milling)법과 기계적 합금화(mechanical alloying) 법으로 합성하였다. stearic acid의 첨가 유무에 상관없이 Co-0.5C-(15∼20)Cr-20Ni-8W-(2∼7)Fe 합금의 경우 6시간 동안 합금화된 금속 분말에서 미세 접합(micro welding) 형상이 균일하게 관찰되었다. stearic acid를 첨가하지 않을 때는 부분적으로 조대화된 분말이 형성되었으나 2% 첨가한 경우 미세하고 판상의 분말이 얻어졌다. stearic acid가 첨가된 복합분말을 열간 압축하여 기계적 성질을 평가한 결과 굽힘강도 1100MPa, 경도 46H(sub)Rc의 특성을 나타냈다. Co-0.5C-(15~20)Cr-20Ni-8W-(2~7)Fe alloy bond in diamond-impregnated abrasive tool was synthesized by ball-milling and mechanical alloying process. When the powders were mechanical alloyed for 6h, micro-welding in most metal powders was observed irrespective of addition of stearic acid. Without stearic acid in metal powders, partial-ly coarse powders were obtained, which could be unfaverable to the densification of composite of composite powders. The hot-pressed compacts showed rupture strength of 1100MPa and hardness of about $46H_{RC}$, respectively.

고성능 폴리머 재질의 포스트-코어 시스템의 생역학적 거동에 대한 예비실험

이기선,김종은,김지환,이정열,신상완,Lee, Ki-Sun,Kim, Jong-Eun,Kim, Jee-Hwan,Lee, Jeong-Yol,Shin, Sang-Wan 대한심미치과학회 2018 Journal of the Korean Academy of Esthetic Dentistr Vol.27 No.2

본 연구의 목적은 기존의 다른 포스트-코어 재료와의 유한요소분석(FEA)의 비교를 통한 치과용 포스트-코어 재료로서의 고성능 폴리머 PEKK의 생체역학 및 장기 안전성을 평가하는 데 있다. 상악 중절치를 모델링 하였으며, 구개 표면에서 치아의 장축에 $45^{\circ}$의 각도로 50N의 반복 하중을 가했다. 전통적으로 사용 된 포스트 코어 재료와 비교하기 위해 3가지 재료 (금, 유리 섬유 및 PEKK)를 시뮬레이션하여 결과를 상호 비교 해 보았다. 상아질보다 낮은 탄성 계수를 갖는 PEKK는 종래의 포스트 코어 재료보다 비교적 치근에 유리한 응력 분포를 보여 주었다. 그러나, PEKK 포스트-코어 시스템은 금속 또는 유리 섬유 포스트-코어 시스템보다 장기간의 반복하중에 대해 타락 및 크라운 파손의 가능성이 더 높을 가능성이 있다. The aim of this study was to evaluate the biomechanical behavior and long-term safety of high performance polymer PEKK as an intraradicular dental post-core material through comparative finite element analysis (FEA) with other conventional post-core materials. A 3D FEA model of a maxillary central incisor was constructed. A cyclic loading force of 50 N was applied at an angle of $45^{\circ}$ to the longitudinal axis of the tooth at the palatal surface of the crown. For comparison with traditionally used post-core materials, three materials (gold, fiberglass, and PEKK) were simulated to determine their post-core properties. PEKK, with a lower elastic modulus than root dentin, showed comparably high failure resistance and a more favorable stress distribution than conventional post-core material. However, the PEKK post-core system showed a higher probability of debonding and crown failure under long-term cyclic loading than the metal or fiberglass post-core systems.

수도산 봉은사 사천왕상의 복장물

이기선 회당학회 2003 회당학보 Vol.8 No.-

여군의 증가 정책에 따른 군대내 성범죄 예방을 위한 소고

이기선 대한성학회 2014 대한성학회지 Vol.1 No.2

우리나라는 여군(이하 여성군인) 증강정책에 의해 전체 군인들 중 에서 여군이 차지하고 있는 비율이 최근 증가하고 있다. 여군의 증 가로 인하여 나타나는 긍정적인 효과도 적지 않지만 (예, 군사 문 화의 개선), 부정적인 효과들도 드러나고 있다. 부정적인 효과들 중의 대표적인 경우가 바로 성차별이나 성범죄 등의 개연성이 높 아지고 있는 것이다. 군대내 성범죄 사건을 예방하거나 사건의 발 생 후 대처하는 방안들은 성군기 사고에방을 위한 의무교육 이수, 성군기 사고에 대한 즉 처벌제도)이 여러 가지이다. 그렇지만 본고 에서는 여성고충상담관 및 병영생활전문상담관 제도의 효율적 이 용에 초점을 맞추어 그 대처 방안을 전개하였다.

메밀가루에 대한 쌀가루 조항원의 IgE - Blot Inhibition 분석

이기선,이수영 대한소아알레르기호흡기학회 1997 Supplement Vol.7 No.2

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알레르기 피부시험을 통한 식물성 식품항원의 양성률 조사

이기선,이수영 대한소아알레르기호흡기학회 1998 Supplement Vol.8 No.1

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