• Title/Summary/Keyword: statement analysis

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STRAIN ON THE LABIAL PLATES AROUND ABUTMENTS SUPPORTING REMOVABLE PARTIAL DENTURES WITH VARIOUS PROSTHETIC DESIGNS: AN IN VITRO STUDY

  • Kim, Seong-Kyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.43 no.3
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    • pp.322-330
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    • 2005
  • Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

Comparison of Topographic, Vegetation, Scenic Resource Distribution between Natural Preservation Zone and Natural Environment Zone in Mt. Teogyu National Park (덕유산(德裕山) 국립공원(國立公園)의 자연보존지구(自然保存地區)와 자연환경지구(自然環境地區)의 지형(地形), 식생(植生), 경관자원(景觀字源)의 분포(分布) 비교(比較))

  • Lee, Chahng-Hah;Ahn, Seung-Mahn;Lee, Kyoo-Seock
    • Journal of Environmental Impact Assessment
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    • v.7 no.1
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    • pp.49-61
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    • 1998
  • Zoning areas within national parks in Korea are classified into Natural Preservation Zone(NPZ). Natural Environment Zone(NEZ), Settlement Zone(SZ) and Mass Facility Zone(MFZ) based on the Natural Park Act Large-scale development which might cause permanent destruction of natural resources are being done in NEZ which covers 90% of the total natural park area. Thus it is necessary to examine National Park Act which refers the authorized criteria and development activities of NEZ. However, the current environmental impact statement(EIS) does not cover the full impact of the development inside the national park area. Based on these concepts, the study examines the appropriate resources to distinguish the NPZ and NEZ in Mt. Teogyu National Park, then compare the distribution of resource characteristics between two area by using GIS. Through this study, the conclusions are as follows; (1) In terms of scenic resource analysis, the current NPZ does not meet the criteria on the National Park Act Rather, most of the resources which should be located within the NPZ are located within the NEZ. (2) In terms of elevation analysis, Mt. Teogyu National Park, most of NPZ are located on high altitude which is more than l,200m above the mean sea level. Therefore, it shows the elevation is the only criteria for distinguishing NPZ and NEZ. (3) In terms of Degree of Green Naturality(DGN), the second forest areas, the eighth grade of DGN in Mt. Teogyu National Park are distributed much more in the NEZ than NPZ. (4) After examining five factors - scenic resources, elevation, slope and DGN, vegetation- it was found out that zoning of Mt. Teogyu National Park is not adequatly designated. Zoning of national parks should be accomplished based on the precise inventory of the current resources.

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Analysis on Habit of Dietary Life for Effective Health-promotion (식생활 유형 분석을 통한 효율적인 건강증진 방안 연구)

  • Lee, Jei-Young;Jang, Dai-Ja
    • The Journal of the Korea Contents Association
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    • v.20 no.8
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    • pp.327-337
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    • 2020
  • This work was researched by practical methodology in-depth study of a subjectivity dimension study, in sloughing away a past habituation of functional quantity analysis on perception-effectivity and a habit of dietary life for effective health-promotion. The perception patterns be generated from this study were classified into three types in Q-method. They are as follows ; it is that divided into 'I[(n=9) : eating type in morning], II[(n=11) : type of no having a midnight meal], III[(n=9) : type of mealing after taking exercise]'. Like this, it found that is very different type all over. Finally, this paper is to examine an acceptance behavior about reception type on effectiveness and a habit of dietary life for effective health-promotion ; to make a proposal in a developmental and creative opinion about it.

An Analysis of the Teaching & Learning Objectives of the Environment Textbooks for the Middle School (중학교 "환경" 교과서의 교수-학습 목표 분석)

  • 구수정;김남례;김미화;권현진
    • Hwankyungkyoyuk
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    • v.14 no.2
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    • pp.28-39
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    • 2001
  • The purpose of this study is to understand the characteristics and the differences regarding the teaching & learning objectives of Environment textbooks for middle school students with the consideration of the 7th Korean National Curriculum. For this the teaching & teaming objectives of three Environment textbooks currently used categorized according to the domain frame of environmental education in the Report of UNESCO(1980). three Environment textbooks and their teacher's guide books are those printed by three companies(A, B, and C) and Joongahng co.. The five objective categories recommended by UNESCO are awareness, knowledge, attitude, skills and participation and six types of skills by National Curriculum Council of England are communication skills, numeracy skills, study skills, problem-solving skills, personal and social skills and information technology skills. It is showed that'Human and Environment'domain is emphasized roughly in the awareness and the knowledge section without any statement of the participation section, 'Environmental Problems and its Counter-plan'domain in the knowledge and the skills section, 'Environmental Conservation'domain in the skills and the participation section of objectives. It is revealed that the skills section of the teaching 8t learning objectives is mainly involved in 'Environmental Problems and its Counter-plan'domain and'Environmental Conservation' domain. According to the result of the analysis of the connectivity between the Environment Curriculum of the 7th Korean National Curriculum and the Environment textbooks regarding objectives stated in the sub-domain level, it says those are generally appropriate ones. But some objectives are emphasized weakly or not at all in several sub-domains such as'The living environment to keep','The environmental problems of the earth','Making environment pleasant'. It is proposed that the efforts to state objectives in the Environment textbooks evenly are needed to be paid (or the well-balanced teaching & teaming of the Environment subject.

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The Effects of Diabetes Management Programs using Mobile App: A Systematic Review and a Meta-Analysis (모바일 앱을 이용한 당뇨환자관리의 효과: 체계적 문헌고찰과 메타분석)

  • Kim, Hee Eon;Kim, EunJa;Kim, Gaeun
    • The Journal of the Korea Contents Association
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    • v.15 no.1
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    • pp.300-307
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    • 2015
  • The purpose of this review was to evaluate the effects of diabetes management program using mobile appllication. A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA Statement was conducted. Studies published between 2004 and 2014 were reviewed using the following databases: Ovid, CINAHL and Cochrane library. The keywords used were (app*OR mobile) AND (nurs* OR health* OR medic*) AND (diabet*). Selected studies were assessed for methodological quality using Scottish Intercollegiate Guidelines Network (SIGN)' Checklist. Three hundred seventy five studies were identified, All the 3 studies found mobile application as a valid strategy on clinical usefulness in diabetes management. This review provides updated evidence for app-based management program in diabetes management. Further studies are needed to increase generalizability using randomized controlled trials, enough sample size. In addition, valid measurements are needed to assess the main outcomes.

THREE-DIMENTIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION FOR DIFFERENT IMPLANT THREAD SLOPE (임플랜트 나사선 경사각이 치조골 응력 분포에 미치는 영향)

  • Seo, Young-Hun;Vang, Mong-Sook;Yang, Hong-So;Park, Sang-Won;Park, Ha-Ok;Lim, Hyun-Pil
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.4
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    • pp.482-491
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    • 2007
  • Statement of problem: The screws of dental implant, having various thread types, can be categorized into different classes by their geometrical form, and each type transmits dissimilar amount and form of stress to alveolar bone. Purpose: The purpose of this study was to find an inclination angle of the screw thread that is favorable in distributing the stresses to alveolar bone. Material and methods: In this study, We used three dimensional finite element analysis with modeling having three types of thread inclination angles and fixed pitch-0.8 mm (single thread type with $3.8^{\circ}$ inclination, double thread type with $7.7^{\circ}$ inclination, triple thread type with $11.5^{\circ}$ inclination). Results: The results obtained from this study were as follows; 1. When the number of thread increased, the amount of Von-Mises stress was reduced since the generated stress was effectively distributed. 2. Since the maximum principal stress affects on the alveolar bone can influence deeply on the longevity of the implants when comparing the magnitude of the maximum principal stress double thread had least amount of stress. This shows that the double thread screw gave best result. Conclusion: In conclusion, double, and triple thread screws were found to be more effective on distribution of the stress than the single thread screws. But, increasing in the thread inclination angle such as triple thread screw relate on the magnitude of the maximum principal stress affecting on the alveolar bone can become problematic. Thus, effective combination of thread number and thread inclination angle can help prolonging the longevity of implant.

A PHOTOELASTIC STRESS ANALYSIS OF FIXED PARTIAL DENTURES WITH BICON IMPLANTS ON MANDIBULAR POSTERIOR AREA (하악구치부에서 Bicon 임플란트에 의해 지지되는 고정성 국소의치의 광탄성 응력분석)

  • Kang, Jong-Un;Kim, Nan-Young;Kim, Yu-Lee;Cho, Hye-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.4
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    • pp.412-424
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    • 2004
  • Statement of problem: Several prosthetic options are available for the restoration of multiple adjacent implants. A passively fitting prosthesis has been considered a prerequisite for the success and maintenance of osseointegration. Passivity is a particular concern with multiple implants because of documented inaccuracies in the casting and soldering process. One way to avoid this problem is to restore the implants individually, however, the restorations of individual adjacent impants requires careful adjustment of interproximal contacts. Purpose: The purpose of this study was to compare the stress distribution pattern and amount surrounding Bicon implants with individual crowns and splinted restorations. Material and method: A photoelastic model of a human partially edentulous left mandible with 3 Bicon implants($4{\times}11mm$) was fabricated. For non-splinted restorations, individual crowns were fabricated on 3 abutments ($4{\times}0.65mm,\;0^{\circ}$, 2.0 mm post, Bicon Inc., Boston, USA) After the units were cemented, 4 levels of interproximal contact tightness were evaluated: open, ideal ($8{\mu}m$ shim stock drags without tearing), medium($40{\mu}m)$), and heavy($80{\mu}m$). Splinted 3-unit fixed partial dentures were fabricated and cemented to the model. Changes in stress distribution under simulated non-loaded and loaded conditions(7.5, 15, 30 lb) were analyzed with a circular polaricope. Results: 1. Stresses were distributed around the entire body of fin in Bicon implants. 2. Splinted restorations were useful for distribution of stress around implants especially with higher loads. 3. By increasing the contact tightness between the individually restored three implants, the stress increased in the coronal portion of implants. Conclusions: Ideal adjustment of the contact tightness was important to reduce the stresses around individually restored Bicon implants.

THE EFFECT OF PERMANENT MAGNET CONNECTING WITH DENTAL IMPLANT ON BONE EXTRACELLULAR MATRIX FORMATION (임플랜트에 연결한 영구자석의 자력이 뼈의 세포외 기질 생성에 미치는 영향에 관한 실험실적 연구)

  • Won, In-Jae;Baik, Jin;Kwon, Kung-Rock;Lee, Sung-Bok
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.5
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    • pp.574-583
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    • 2006
  • Statement of problem : The use of permanent magnetics is increasing in implant dentistry. Purpose : This study is to know the effect of permanent magnetics on bone matrix formation of osteoblasts. Materials and methods : The konus abutment-shaped permanent magnetics were connected to the implant fixture, and placed on the culture plate. The osteoblast-like cell Mc3T3E1 were used for cell culture. As the control group, the implants were connected to titanium healing caps, and cultured in the same conditions of experimental group. After 3. 7, 14 days, cells were cultured, and we measured and compared the amount of collagen type I, osteocalcin, which is bone matrix protein by Western immunoblotting analysis. Results: As a result of Western immunoblotting analysis for estimating the amount of bone extracellular matrix, there was no difference between osteoblast of the experimental group and the control group during 3 and 7day-osteoblast culturing. However when cells were cultured for 14days, the amount of bone extracellular matrix was increased, on the experimental group. Conclusion: From these results, magnetic field of permanent magnetics might have effect on bone formation of osteoblast, especially at initial stage of implant placement. Therefore, their clinical application for implant or bone graft could be possible.

ON THE BONE TISSUE REACTION TO IMPLANTS WITH DIFFERENT SURFACE TREATMENT METHODS (임플랜트 표면 처리 방법에 따른 골조직 반응에 대한 연구)

  • Kim, Yong-Jae;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.1
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    • pp.71-84
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    • 2007
  • Statement of problem: Implant surface characteristics plays an important role in clinical success and many studies have been made for improvement of success by changing surface roughness. Purpose: Appropriate increase of surface roughness increases the activity of osteoblast and enhance contact and retention between bone and implant. Material and method- Machined, SLA and RBM surface implants, which are the most commonly used implants were implanted into the tibia of rabbits and after 1 week, 4 weeks, 8 weeks and 12 weeks there were histologic and histomorphometric analysis and study for bone gradient and change of Ca/P ratio using EDS(Energy Dispersive X-ray Spectroscope). Results: Comparison of bone-implant contact showed no significant difference among each implant. In comparison of bone area rates, SLA showed higher value with significant difference at 1 week and 4 weeks, and SLA and RBM at 8 weeks than Machined implant (p<0.05). In analysis of bone constituents with EDS, titanium was specifically detected in new bones and the rates were constant by surface treatment method or period. In case of Ca/P ratio, according to surface treatment method, each group showed significant difference. Lots of old bone fragments produced during implantation remained on the rough surface of RBM implant surface and each group showed histological finding with active synthesis of collagen fibers until 12 weeks. In transmission electronic microscopic examination of sample slice after elapse of twelve weeks, tens nm of borderline (lamina limitans like dense line)was seen to contact the bone, on the interface between bone and implant. Conclusion: SLA and RBM implant with rough surface shows better histomorphometrical result and the trend of prolonged bone formation and maturation in comparison with Machined implant. In addition, implant with rough surface seems to be helpful in early stage bone formation due to remaining of old bone fragments produced in implantation. From the results above, it is considered to be better to use implant with rough surface in implantation.

A STUDY ON THE VERTICAL AUGMENTATION OF THE ALVEOLAR RIDGE BY DISTRACTION OSTEOGENESIS IN DOGS (성견에서 치조골 신장술을 이용한 수직적 골 증강에 관한 연구)

  • Lee, Joo-Ho;Lim, Ju-Hwan;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.1
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    • pp.107-118
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    • 2007
  • Statement of problem: Implant-type distractor uses a removable distraction device that has an appearance similar to that of a dental implant and utilizes many of the same techniques for placement as are used for dental implants. Material and method: In this study, 48 implant type titanium distractors were inserted into the osteotomized alveolar bone of 12 beagle dogs. After a 7-day latency period, the alveolar bone was augmented by 5mm vertically at a rate of 1.0 mm/day. The dogs were sacrificed after 4weeks, 8weeks and 12 weeks for radiographic, histologic, and histomorphometric analysis. Result: Copper equivalent value showed significant difference between 4 weeks and the other weeks(8, 12 weeks)(p<0.05). But there was no significant difference between maxillary and mandibular groups. In the bone to metal contact analysis, there was a significant difference between 4 weeks and 12 weeks(p<0.05). On the contrary, there was no significant difference between maxilla and mandible. The bone area showed significantly higher values in 12 weeks compared to 4 weeks(p<0.05). Histologically mineralization began at the host bone margins. At 12 weeks, increasing accumulation of $Ca^{++}$ element was confirmed. Conclusion: From the results above, the new bone formation was increased according to consolidation period. Especially there was significant difference between 4 weeks and 12 weeks(p<0.05). Implant type distractors used in this study to augment vertical ridge defect may prove to be a clinically useful treatment option in selected cases.