Influence of different types of resin cement on the fracture resistance of teeth restored with MOD ceramic inlays

치과대학/석사The purpose of this study was to evaluate the influence of 3 different types of resin cements on the failure of teeth restored with ceramic inlays using a universal testing machine. Seventy-five intact, caries-free human maxillary premolars were divided into 5 groups cavity preparation and restoration with IPS e.max CAD by Variolink N; Group 3, MOD cavity preparation and restoration with IPS e.max CAD by RelyX Unicem; Group 4, MOD cavity preparation and restoration with IPS e.max CAD by Multilink sprint; and Group 5, MOD cavity preparation and no restoration. Compressive force was loaded only on the cuspal inclination of tooth. Class II MOD preparation was as follows. The pulpal floor was formed at a depth of 2 mm from the occlusal cavosurface margin of the preparation, and the isthmus was half of vi the intercuspal distance. The proximal box width was 1.5 mm, and the axial wall was 2 mm in height. Margins were prepared with 90-degree cavosurface angles. Specimens were tested with a universal testing machine at 1.0 mm/min using steel sphere plungers (6.0mm in diameter). Peak load to fracture (N) was measured for each specimen. Means were calculated and analyzed with a one-way ANOVA and Tukey’s test (α=0.05). The mean peak fracture loads (N, mean ± S.D.) were as follows: Group 1 - 1371.29 ± 455.86, Group 2 - 1188.18 ± 408.79, Group 3 - 1097.38 ± 443.64, Group 4 - 1134.69 ± 352.13, Group 5 - 624.08 ± 259.03. Based on the results obtained under in vitro experimental conditions, the following conclusions were drawn. There was no statistical difference of fracture load between intact teeth and restored teeth. Although Group 2 (Variolink N) showed superior fracture load than Group 3 (RelyX Unicem) and Group 4 (Multilink speed), no statistical difference was found. Groups 3 and 4, using self adhesive resin cements, showed unfavorable fracture patterns more frequently than Groups 1 and 2. Fracture resistance of teeth restored with ceramic inlays was comparable with that of intact teeth, regardless of the type of resin cements used in this experiment.ope

사료 내 복합효소제의 첨가가 이유 자돈의 성장성적, 영양소 소화율, 혈액성상, 분변 내 미생물 및 휘발성 지방산에 미치는 영향

학위논문 (석사)-- 서울대학교 대학원 : 농생명공학부, 2013. 8. 김유용.우리나라 사료시장의 규모는 세계 14위 권, 유럽연합을 1개의 단위로 보면 10위권 안에 위치할 정도로 큰 시장규모를 보인다. 하지만 90% 이상의 원료를 수입에 의존하고 있기 때문에 최근 경제위기, 유가상승 및 그로 인한 바이오연료 (biofuel)의 생산, 그리고 중국의 곡물소비량이 폭발적으로 증가함에 따라 원료사료 가격이 급격히 상승하여 일반 농가의 사료비에 대한 부담감이 점점 가중되고 있는 실정이다. 이러한 원료사료의 가격 상승은 사료 내 소화율을 높여 전체적인 효율을 증가시키기 위한 연구가 활발하게 진행되는 계기가 되었으며, 효소제 (단일 및 복합 효소제)는 여러 연구 중에서 중요한 자리를 차지하고 있다. 축산 시장에 셀 수 없이 많은 효소제 제품이 판매되고 있지만 체계화된 평가 방법이 없어 그 효과를 규명하기에는 많은 어려움이 있다. 본 실험에서는 이러한 배경을 바탕으로 사료 내 소화효소 (peptidase, amylase) 및 NSP 분해 효소 (xylanase, cellulase and α-galactosidase)가 복합된 효소제의 첨가가 이유자돈의 성장성적 및 영양소 소화율에 미치는 영향과 영양소 소화율과 in-vitro 소화율과의 상관관계를 규명하였다. 실험: 사료 내 복합효소제의 첨가가 이유 자돈의 성장성적, 영양소 소화율, 혈액성상, 분변 내 미생물 및 휘발성 지방산에 미치는 영향 평균체중 8.51 ± 1.47 kg인 168두의 이유자돈([Yorkshire × Landrace] × Duroc)을 체중 및 성별을 고려하여 4처리 6반복, 돈방당 7두 (3반복 암컷 4두, 잔여 3반복 암컷 두)의 완전임의배치법으로 총 5주간의 사양실험에 배치하였다. 기간별로 총 2단계의 실험사료에 각각 0, 0.1, 0.2, 0.3 %의 복합 효소제가 옥수수-대두박-보리 위주의 사료 내 첨가되었으며, 각 단계 내에서 모든 처리구의 사료 내 영양소 함량은 모두 동일하도록 하였다. 사양실험 전기간 사료와 물은 자유채식토록 하였다 (ad libitum). 각각의 사양기간 및 전 기간 동안 복합 효소제를 0.1 ~ 0.3 % 첨가한 처리구들이 체중 및 일당증체량이 대조구에 비해 유의적으로 개선되었다 (quadratic, P0.05), whereas quadratic responses (P<0.05) were detected in nitrogen (N) urine and N digestibility. There were no significant differences in the blood profiles of blood urea nitrogen and total protein level. However, glucose level was increased as dietary NSP enzyme complex increased at 2 week (quadratic, P<0.05). Base on fecal microflora results, the number of fecal pathogenic Escherichia coli (E. coli) did not differ among all treatment, whereas fecal Lactobacillus counts were increased with dietary NSP enzyme complex level increased at 5 week. The inclusion level of dietary NSP enzyme complex in weaning pigs diet linearly down regulated in total volatile fatty acid, acetate and propionate in feces (linear, P<0.01). Results from this experiment suggested that dietary NSP enzyme complex ranged 0.1 to 0.2 % with dietary fiber ingredient might have beneficial effects on weaning pigs by a increase of growth performance and an increment of fecal Lactobacillus count.Summary i Contents iii List of Tables v List of Figures vii List of Abbreviations viii Ⅰ. Introduction 1 Ⅱ. Review of Literature 3 1. Global and Korean livestock industry 3 2. Enzyme and livestock industry 7 2.1. General information of enzyme 7 2.2. Classification of Enzyme 8 2.3. Need of enzyme in animal nutrition 9 3. Non Starch Polysaccharide and NSP enzyme 10 3.1. Definition and classification of NSP 10 3.2. NSP in feed raw material 13 3.3. Anti-nutritive effect of NSP 14 3.4. Improving the nutritive value of feedstuffs 19 3.5. Mode of action of NSP enzyme 21 4. Feed enzyme in swine 22 4.1. NSP enzyme 22 4.2. Protease and amylase 23 Ⅲ. Effect of Dietary Enzyme Complex Supplementation on Growth Performance, Nutrient Digestibility, Blood Profiles, Fecal Microflora and Volatile Fatty Acid in Weaning Pigs 26 Abstract 26 Introduction 28 Materials and methods 29 Results and discussion 33 Conclusion 39 Ⅳ. Literature Cited 50 Ⅴ. Summary in Korean 60 Ⅵ. Acknowledgement 62Maste

Spin-up of a fluid in an axisymmetric rotating container with cone-shaped bottom

학위논문(석사) - 한국과학기술원 : 기계공학과, 1994.2, [ ii, 33 p. ]한국과학기술원 : 기계공학과