Effect of the Surface Treatment by Airborne-particle Abrasion on the Shear Bond Strength of Resin Cement to Hybrid Ceramic

오남식,Batzaya Tumur-ulzii,조성찬,함미현,김원호,이명현 대한통합치과학회 2019 대한통합치과학회지 Vol.8 No.3

The aim of this study was to investigate the effect of airborne-particle abrasion(APA) treatment on the shear bond strength of resin cement to hybrid ceramic, MAZIC Duro(Vericom, Korea). The hybrid ceramic specimens were treated with airborne alumina oxide particles and bonded with 6 types of resin cement (Rely X Ultimate Clicker, Multilink N, U-Cem, Super Bond C&B, Panavia F 2.0, and BisCem). All the steps were performed by the same operator according to the manufacturer's instructions of resin cement respectively. All specimens were subjected to shear bond strength testing using a universal testing machine with a crosshead speed of 1mm/min. All data were statistically analyzed using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). In this study, hybrid ceramic bonded with Super Bond and Rely X Ultimate Clicker were significantly stronger than those bonded using other resin cement (p<0.05).

Margin Design

오남식 대한치과의사협회 2003 대한치과의사협회지 Vol.41 No.8

Synergistic Effect of Bone Marrow-Derived Mesenchymal Stem Cells and Platelet-Rich Plasma on Bone Regeneration of Calvarial Defects in Rabbits

오남식,윤정호,유재흥,최성호,이명현,이상진,송순욱 한국조직공학과 재생의학회 2012 조직공학과 재생의학 Vol.9 No.1

Bone tissue regeneration techniques include tissue engineering approaches which employ mesenchymal stem cells as an osteogenic agent for bone repair. Recent studies have demonstrated that tissue engineering scaffolds and growth factors can support cell proliferation, bone formation, and bone tissue repair in lost bone tissue. Furthermore,many studies have suggested that platelet-rich plasma (PRP) can improve bone regeneration due to the numerous growth factors that it contains. This study was performed to investigate the influence of bone marrow-derived mesenchymal stem cells (BMMSCs) and PRP on bone regeneration of calvarial defects in rabbits. Hydroxyapatite (HA) was used as a scaffold for bone regeneration. There were three groups in this experiment: 1) HA loaded with BMMSCs (HS group), 2) HA loaded with PRP (HP group), and 3) HA loaded with BMMSCs and PRP (HSP group). Bone tissue regeneration techniques include tissue engineering approaches which employ mesenchymal stem cells as an osteogenic agent for bone repair. Recent studies have demonstrated that tissue engineering scaffolds and growth factors can support cell proliferation, bone formation, and bone tissue repair in lost bone tissue. Furthermore,many studies have suggested that platelet-rich plasma (PRP) can improve bone regeneration due to the numerous growth factors that it contains. This study was performed to investigate the influence of bone marrow-derived mesenchymal stem cells (BMMSCs) and PRP on bone regeneration of calvarial defects in rabbits. Hydroxyapatite (HA) was used as a scaffold for bone regeneration. There were three groups in this experiment: 1) HA loaded with BMMSCs (HS group), 2) HA loaded with PRP (HP group), and 3) HA loaded with BMMSCs and PRP (HSP group). Two circular bony defects (6 mm in diameter) were made in rabbit calvaria using a trephine bur. BMMSCs and PRP with a HA scaffold (diameter 5.5 mm, height 3 mm) were applied to each defect. The animals were sacrificed after 2 weeks, 4 weeks and 8 weeks. The level of their ability of osteogenesis was evaluated through histological and histomorphometric analyses. High-quality bone regeneration was observed in the HSP group. The percentage of new bone area around the scaffolds was higher in the HSP group than it was in the other groups (HS and HP group), especially at 8 weeks (HS, 72.5±15 %; HP, 85.8±14 %; HSP, 98.8±2.5%). In addition, the level of bone maturation was higher in the HSP group than in the other groups. The results of this study show that PRP has a positive effect on bone generation. HA with a combination of BMMSCs and PRP can enhance bone regeneration. In addition, the growth factor capacity of PRP may affect the differentiation of BMMSCs and promote bone formation.

보철물의 수명 연구를 위한 온라인 평가 시스템 구축

오남식,박영범,유진주,윤준호,윤승환 대한통합치과학회 2019 대한통합치과학회지 Vol.8 No.1

A survey of dental prosthetic life expectancy is important not only because it provides the evidence of dental prosthodontic insurance benefits, but also because it is an objective standard for the agreement of increasing disputes between patients and dentists. Prospective clinical trial and definite prosthesis evaluation criteria is essential for the validity of prosthesis life survey. However, in Korea, there are very few researches that satisfy these criteria. The purpose of this study is to review the previous life expectancy surveys of the dental prosthesis, and to introduce the criteria used for evaluation of the prosthesis and the evaluation criteria for the newly introduced from the Korean Academy of Prosthodontics. Online evaluation system will also be learned more, which allows new institutions to input, collect and process new evaluation criteria in a convenient way. The data obtained through this system will be used in the future to provide more reliable prosthesis life expectancy survey data. 보철물 수명 조사는 치과 보철 치료의 급여화에 따른 보험 정책 수립 뿐 아니라, 증가하고 있는 환자와 의사와의 분쟁의 조정을 위한 객관적 기준이 되기 때문에 중요하다. 타당성을 만족하는 보철물 수명 조사를 위해 명확한 보철물 평가 기준이 필요하고 이를 통한 전향적인 임상연구가 필수적이다. 하지만 국내에서 보고된 문헌들을 살펴보면 이런 기준을 만족시키는 연구가 매우 적은 것이 현실이다. 이 연구에서는 현재까지 문헌에서 소개된 보철물 수명 조사를 살펴보아 앞으로 지향해야 할 수명 연구의 방향을 알아보고, 보철물 평가를 위해 사용된 기준들과 대한치과보철학회에서 새로 제시한 보철물 평가 기준을 소개하고자 한다. 또한 새로운 평가 기준을 여러 기관에서 편리하게 입력, 수집, 가공할 수 있는 온라인 평가 시스템에 대해 자세히 알아보고 향후 이 시스템을 통해 얻어진 자료를 가지고 보다 객관적이고, 광범위한 샘플을 통해, 보다 신빙성 있는 보철물 수명 자료를 얻는 방법을 소개하고자 한다.

Multidiscplinary Approach to Treat Traumatized Anterior Tooth in a Korean Adolescent: a Case Report of Orthodontic Forced Eruption and Esthetic Hybrid Ceramic Restoration

오남식,김지혜,최태현,조가영,김소현,노지영 대한통합치과학회 2017 대한통합치과학회지 Vol.6 No.1

Loss of the coronal part of a permanent incisor in a young patient can cause esthetic and functional problems which may cause emotional stress. In case of complicated crown-root fracture below gingival level, establishing proper biological width is critically important. We reviewed on a patient who had fractured anterior tooth. With multidisciplinary approach, endodontic, orthodontic, and prosthodontic treatments were planned. Orthodontic forced eruption was designed to provide sufficient tooth structure with proper dentogingival relationships and to place a single crown restoration.

아기-알지네이트 연합 인상체의 보관방법 및 idophor 침적소독에 의한 체적 변화에 관한 연구

오남식,서정민,김선희,윤영아,심준성,Oh Nam-Sik,Seo Joung-Min,Kim Sun-Hee,Youn Young-Ah,Shim Joon-Sung 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.1

Statement of problem : Because dental impression can be a cross-infection source, disinfection, such as immersion disinfection is nessecary. However, the disinfection process may change the volume of the impression cast. Purpose : The purpose of this study is to find out the effects on dimensional change of different storage times and methods, of agar-alginate impression when immersed in a 5% idophor disinfectant. Material and Methods : An agar-alginate impression was made from a mandible model and then was disinfected and stored according the experimental conditions and a stone model was produced. Measurements were taken between reference points on the original mandible model and they were compared to measurements taken between reference points on the stone model. The study was divided into 4 groups. In group 1, the impression was stored in a 100% humidor for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours and 24 hours and stone models were made at each time. In group 2, the impression was immersed in 5% idophor disinfectant and then stored in a 100% humidor for the same length of times as group 1, and stone models were made at each time. In group 3, the impression was stored in extend-A-pourR, a special storage solution for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 12 hours, 24 hours 3 days, and 7 days and stone models were made at each time. In group 4, the impression was immersed in 5% idophor disinfectant and then stored in stored in extend-A-pourR, a special storage solution for the same length of times as group 3, and stone models were made at each time. 5 impressions and stone models were made at each time to make a total of 180. The Student-t test (P < .05) was used to do a statistical analysis of the measurements of the mandible model and stone models. The repeated-measure 2-way analysis of variance (P < .05) was used to do a statistical analysis of the difference in the 4 groups. Results : The percent liner dimensional change was from $0.25{\pm}0.03%$ (group 1, 30 minutes) to $0.34{\pm}0.06%$ (group 4, 7 days). No significant change was noticed between the 4 groups. Conclusion : According to the above study, in both methods, least dimensional change was recorded when the storage times were short and in both methods, immersion in 5% idophor disinfectant did not effect dimensional change in the agar-alginate impression.

최적설계기법을 이용한 완전도재 가공의치의 연결부 형태 보강

오남식,김한성,이명현,이근우,Oh Nam-Sik,Kim Han-Sung,Lee Myung-Hyun,Lee Keun-Woo 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.2

Statements of problem: All ceramic fixed partial denture cores can be made by the slip casting method and the advanced alumina tape method. The fracture resistance of these core connector areas is relatively low. Purpose: The purpose of this study is to standardize the appropriate volumetric figure and location of the connectors in the alumina core fabricated in alumina tape to be used in fixed partial dentures by way of topology optimization. Material and method: A maxillary anterior three-unit bridge alumina core with teeth form and surrounding periodontal apparatus model was used to ultimately design the most structurally rigid form of the connector. Loadings from a $0^{\circ}$, $45^{\circ}$ and $60^{\circ}$ to the axis of each tooth were applied and analyzed with the 3-D finite element analysis method. Using the results from these experiments, the topology optimization was applied and the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture core was designed. Results: The modified prosthesis with the form of a bulk in the lower lingual surface of the connector in the event, reduced the stress concentration up to 20% in the 3-D FEA. Conclusion: The formation of a bulk in the lower lingual connector area of an alumina core for a fixed partial denture decreases the stress to a clinically favorable measure but does not harm the esthetic point of view. This result illustrates the possibility of clinical application of the modified form designed by the topology optimization method.

알루미나 테이프를 사용한 유리 침투형 알루미나 코아의 변연적합도

오남식,이명현,김대준,이근우,이선형,Oh, Nam-Sik,Lee, Myung-Hyun,Kim, Dae-Joon,Lee, Keun-Woo,Lee, Sun-Hyeong 대한치과보철학회 1998 대한치과보철학회지 Vol.36 No.6

The purpose of this study was to compare the marginal fit of all ceramic crowns prepared from alumina slip casting, which is consistent with the conventional In-ceram system, and those fabricated from alumina tapes which is currently under development in an effort to alleviate complexities involved in the forming procedure of the In-ceram crown core. All ceramic crowns, made of In-ceram(slip casting) and alumina tapes(Doctor blade casting), were prepared with $90^{\circ}\;and\;135^{\circ}$ shoulder margins. The crowns were cemented with a glass ionomer cement and embeded in epoxy resin. The embedded crowns were sectioned faciolingually and mesiodistally and marginal discrepancies and marginal gaps were measured under the Measurescope MM II. The measurements were analyzed using Wilcoxon rank sum test and Kruskal-Wallis test and the results were as follows: 1. In the case of $90^{\circ}$ shoulder margin, the combined marginal discrepancies and marginal gaps were $78.3{\mu}m\;and\;44.4{\mu}m$ respectively, for the all ceramic crowns fabricated using the alumina tapes. In comparison, the values were $65{\mu}m\;and\;25.5{\mu}m$ for the In-ceram crowns. For the marginal gaps a statistical difference existed (p<0.05) but no significant difference was observed for the marginal discrepancy (p>0.05). 2. In the case of $135^{\circ}$ shoulder margin, the combined marginal discrepancy and marginal gaps were $82.1{\mu}m\;and\;40.2{\mu}m$ respectively, for the all ceramic crowns formed with the tapes. As compared with the marginal discrepancy and gaps of the $90^{\circ}$ shoulder margin in the fabricated from the alumina tapes, no significant statistical differencies were discerned in both cases (p>0.05). 3. There was no statistically significant difference in the fits among four locations around the margins of the all ceramic crowns fabricated using the alumina tapes. The results obtained in this study showed that the marginal fits of the glass infiltrated alumina cores fabricated from the alumina tapes are slightly higher value than those prepared using the In-ceram but the difference is within a clinically acceptable range.

지르코니아의 다양한 표면처리방법에 따른 레진시멘트와 전단결합강도 비교 연구

오남식,이명현,김원호,김효정,조성찬,함미현 대한통합치과학회 2018 대한통합치과학회지 Vol.7 No.2

This study was designed to evaluate the effect of hot-HF etching surface treatment on the shear bond strength between zirconia and resin cement. Zirconia surfaces was randomly divided into 4 groups(n=10) according to different treatments (blank control; Airborne-Particle-Abrasion(APA); hot-etching with 9% HF gel(HE); combine with Airborne-Particle-Abrasion and hot-etching with HF gel(APA+HE)). After surface treatment, painted with primer (Monobond N) previously, was applied and resin cement (Multilink N) cylinders (diameter: 2.0 mm) were bonded. All specimens were subjected to shear bond strength testing using a universal testing machine with a crosshead speed of 0.7mm/min. All data were statistically analyzed using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). The zirconia surface of different treatment produced higher bond strength than control without surface treatment. Otherwise, no significant difference was detected between different treatment groups (P< 0.05). The shear bond strength of APA following by Hot-HF etching treatment decreased. Surface treatment of zirconia with hot-HF etching gel enhanced the surface roughness and bond strength between the zirconia and the resin cement.

교양기초교육과정 운영 사례 : 성균관대학교 사례를 중심으로

남식용(Nam, Sik Yong),이병철(Lee, Byoung Chul) 한국교양교육학회 2009 교양교육연구 Vol.3 No.1

21세기는 우리나라 대학교육의 패러다임에 몇 가지 의미 있는 변화를 가져왔다. 대학입시에서의 대단위 모집단위의 확산과 학부제, 전공진입제 등 형태상의 변화로 표현되는 그러한 모습들과 더불어 교육적이며 실질적인 측면에서도 몇 가지 결과를 우리 대학사회에 가져왔다. 특히, 그 중에서도 눈에 띄는 변화는 대학에서의 교양교육의 강화라 할 것이다. 물론 과거에도 의미 있고 중요한 교육으로서의 교양교육은 이루어져 왔다. 그러나 전공영역에 종속된, 혹은 단순히 학부 저학년을 대상으로 한 그저 편안하게 가르치고 배울 수 있는 가벼운 교과과정 정도로 인식되어 온 것도 사실이라 할 것이다. 다행인 것은 이러한 과거의 인식은 최근, 질적으로 우수한 교양교육이야말로 대학교육의 경쟁력을 강화시킬 수 있는 주요한 밑바탕이라는 공감대와 더불어 일정 정도 불식되고 있다는 것이다. 성균관대학교 역시 그러한 인식에 바탕을 두고 교양교육의 강화를 우리 학교의 장기발전계획인 VISION2010+ 5대 전략과제의 하나로 천명하고 있으며, 그 시행과 결실의 첫단계로 2005학년도에 교양기초교육과정을 전면 개편한 바 있다. 또한 교양기초교육을 총괄하는 교육기관으로 학부대학을 별도로 출범시켜 현재에 이르고 있는데, 본 글을 통해 그간 이루어져 왔던 교양기초교육의 경쟁력 강화를 위한 학부대학의 노력을 몇 가지 주요 특징적 운영사례를 중심으로 살펴보고자 한다. 우선 성균관대학교 교양기초교육의 현재 상황을 간략히 언급하고, 이어 2005학년도 교육과정 개편에 따른 교양기초교육의 변화상을 가늠해 볼 수 있는 사례로서 글쓰기(커뮤니케이션)교육의 강화 측면을 살펴보고자 한다. 또한 대학교육의 국제화를 위한 노력의 하나인 기본영어 교육의 강화사례를 살펴보고 기초영역에서의 수준별 교육과정 운영현황 또한 살피게 될 것이다. 마지막으로는 교양기초교육의 질적 수월성을 담보해 낼 수 있는 교육과정에 대한 운영 평가와 개편의 독특한 사례를 되짚어 보고 교양기초교육 강화의 가장 주요한 요소라 할 수 있는 우수한 교수자원의 확보 및 지원방안에 대해 살펴보고자 한다. The 21st century has brought several meaningful changes to the paradigm of Korean university education. It has brought several results along with such formal changes as spread of large admission units in entrance examination, faculty system, and major entry system to university society in educational and practical aspects. Especially, the most outstanding change is reinforcement of liberal arts courses in universities. The liberal arts courses existed as an important educational method in the past, too. However, they were recognized to be subordinate to major field or to be light courses only for freshmen and sophomores. Fortunately, this old recognition is getting weak with consensus that excellent liberal art courses can strengthen competitiveness of university education. Sungkyunkwan University(SKKU) declared that reinforcement of liberal arts courses is one of VISION2010+ 5 strategic agenda and reorganized the liberal arts and basic education courses completely in 2005 as the first step. Furthermore, SKKU organized University College which takes charge of liberal arts courses. We can see the efforts of University College to strengthen competitiveness of liberal arts courses through examining principal operation cases. Current status of SKKU liberal arts and basic education courses will be mentioned in the first place, and reinforcement of writing(communication) education will be examined as a case. Moreover, a case of basic English education reinforcement which is one of the efforts to globalize university education and the operation status of differential education in basic courses will be examined as well. Finally, operational assessment for education curriculum which ensures qualitative excellence of liberal arts courses, and professor resources procurement plan which is the most important part of liberal arts courses reinforcement will be examined sequentially.