• 대한치과보철학회지
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• 제25권1호
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• pp.341-353
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• 1987

The purpose of this study was to investigate the gingival response to the location of the crown margin and the gingival response to the period of crown placement. Twenty one patients were selected for this study. The patients fitted into the research condition. The crown margins of anterior teeth were located at crest and supragingivally. The crown margins of posterior teeth were located at crest, subgingivally and supragingivally. Plaque index and gingival index were measured before tooth preparation and 1 week,4 weeks, 6 weeks after crown placement. The results were as follows: 1. There was no significance in the gingival response to the location of crown margin in short term period. 2. As the period of crown placement was extended, plaque index and gingival index were gradually increased. 3. Plaque index and gingival index of tooth surfaces were increased in the order of the interproximal surfaces, lingual surfaces and buccal or labial surfaces.

• The Journal of Advanced Prosthodontics
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• 제4권3호
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• pp.134-138
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• 2012

PURPOSE. The study was conducted to evaluate the efficacy of implant supported tooth replacement in diabetic patients. MATERIALS AND METHODS. The study involved placement of implants (UNITI implants, Equinox Medical Technologies, Zeist, Holland, diameter of 3.7 mm and length 13 mm) in five diabetic patients (three females and two males) of age ranging from 35-65 years with acceptable metabolic control of plasma glucose. All patients included in the study were indicated for single tooth maxillary central incisor replacement, with the adjacent teeth intact. The survival of the restored implants was assessed for a period of three months by measurement of crestal bone heights, bleeding on probing and micro flora predominance. Paired t-test was done to find out the difference in the microbial colonization, bleeding on probing and crestal bone loss. P values of less than 0.05 were taken to indicate statistical significance. RESULTS. Results indicated that there was a significant reduction in bleeding on probing and colonization at the end of three months and the bone loss was not statistically significant. CONCLUSION. The study explores the hypothesis that patients with diabetes are appropriate candidates for implants and justifies the continued evaluation of the impact of diabetes on implant success and complications.

• 대한치과기공학회지
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• 제21권1호
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• pp.97-114
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• 1999

The first function of occlusion is mastication. Therefore the functional restoration of occlusal surface is very important. The restoration of occlusal surface is three method as wax bite technique, F.G.P. technique, cone technique. Many dental technician is using compound method. I have knew common point on each teeth during I have waxing up wax pattern. So I studied on the design waxup technique for maxillary molar occlusion. The results of the study were as follows ; 1. The dam wax up method can restore axial contour of teeth very easy and make short working time of wax pattern. 2. The height of dam must be same with cusp of adjacent teeth. 3. Automatically the contour of tooth is appeared if the contour of dam is relationship with cuspid line of adjacent teeth. 4. The height of contour of buccal, lingual surface is formed natural curve to add fluid wax by gravitation. 5. The development groove of Maxillary premolar is appeared V form. 6. The development groove of Maxillary molar is appeared W form. 7. The embrasure is formed to carve around contact point area as round convex. It affects to axial form of tooth. 8. I was knew that the lingual groove and stuart's groove of molar runs parallel with oblique ridge. 9. The buccal groove of molar is formed parallel with direction of teeth arrangement.

• 한국의상디자인학회지
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• 제17권1호
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• pp.53-68
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• 2015

The purpose of this study is to analyze check pattern of nail art from 2011 to 2013. The results of this study are as follows; 1) Check pattern of nail art is total 257 patterns, and there are 84 argyle, 29 tartan, 24 harlequin, 24 over, 23 window-pane, 15 stitcheds, 13 hound tooth, 10 block, 10 madras, 8 gingham, 8 gradation, 7 shepherd, and 2 tattersall check patterns. Through this result, in nail art, the relatively simple patterns such as a vertical pattern, a horizontal pattern, and cross or overlap diagonal line are used more than elaborate and complex check patterns of a fibrous tissue from a weaving process. 2) In check pattern of nail art, N-affiliated color and R-affiliated color are remarkably well-used, because of the effects of argyle, tartan, window-pane, harlequin, stitched, over, and hound tooth check patterns used the most during the past three years. Especially, most tartan, harlequin, over, and hound tooth check patterns use their own special colors such as R-affiliated colors and N-affiliated colors as it is, and argyle, window-pane, stitched, and over check patterns use well by arranging N-affiliated colors and R-affiliated colors. 3) The most used expressive technique is hand painting to express check pattern in nail art, because new products related to UV gel are well launched. These materials can draw fine line that is hard to express by existing polish easily and simply, and not only have set quickly hard, so procedure time is very short, so it is compatible to draw check pattern personally, but also it is well covered, so check pattern is more clearly expressed.

• 대한소아치과학회지
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• 제41권2호
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• pp.157-165
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• 2014

매복된 미성숙 영구치는 매복의 깊이와 방향이 정상 맹출로에 크게 벗어나 있지 않는다면 물리적인 원인 제거 후 자발적 맹출이 가능하다. 그러나 자발적 맹출이 일어나지 않는다면 골격성 고정원을 이용하여 교정적 견인을 하게 된다. 골격성 고정원 중 하나인 C-tube는 인접 치근 사이의 피질골상에서 4~5 mm의 짧은 여러 개의 미니 스크류로 치근 하방 부위에 고정되어 안정적이고, 초기 영구치열기 환자의 치아 손상의 가능성이 적다. 구부릴 수 있는 성질 때문에 견인력의 방향 조절도 가능하다. 매복치의 반대편 악궁에 식립 후 교정용 탄성 고무링을 이용한 수직적 견인이 가능하여 매복치를 원하는 위치에 견인할 수 있다. 하지만 C-tube의 식립 및 제거 시 절개가 필요하고, 환자의 협조가 요구된다. 또한 매복치의 견인 시, 미성숙 영구치의 치근 성장과 골, 부착 치은의 형성 등을 주의 깊게 관찰하고 주변 연조직의 염증이 생기지 않도록 치태 조절과 구강 위생 관리 교육이 필요하다.

• 한국정밀공학회지
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• 제3권3호
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• pp.40-71
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• 1986

By developing a computer program for the systematic design of worm gears, the design formulae and tables of AGMA, JGMA, BS and DIN are analized and compared. The computer program can be used on micro-computers. According to the input data of the reduction ratio, the center distance. the driving torque and the material as design parameters, the program calculate the most efficient worm gear dimension. The variation of the design parameters and other empirical coefficients in case of resulting an inadequate design gear dimension can be easily modified throuth the way of interactive method between the user and the monitoring system of computer. A proposal of the standardization of worm gears was made in which a standard module according to the DIN 323 standard series number was applied. For the more exact and effective calculation of the stress concentration and the deformation of gear teeth, a computer program using the boundary element method is also developed. Even the strength of the special gear shape such as Niemann's "Cavex" gear can be calculated in a short CPU-time. The most effort of this study has been layed on the developing a computer program for the correction of a tooth profile and face width which is most important design factor for an exact and wide teeth contacts under loads, especially by great and wide gears. For this purpose were investigated the tooth stiffness, the mesh interferences and the kinematics and the dynamics of gear mesh. The deflection and the deformation of the gear shaft due to the loads acting on gear and shaft were aslo considered. Some examples have shown the sufficient good status of teeth contact in which the correction of the tooth profile and face width were accomplished due to the calculated results.d results.

• 대한치과교정학회지
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• 제42권3호
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• pp.138-143
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• 2012

Objective: To evaluate the short-term effect of fangchinoline, an anti-inflammatory drug widely used in Asia, on root resorption that is associated with orthodontic tooth movement. Methods: Twenty-four Wistar rats were randomly divided into 6 groups. Mesial forces of 0, 50, or 100 g were applied to the maxillary first molar of the rats in each group for 14 days by activating nickel-titanium closed-coil springs. One-half of the rats receiving each of these treatments also received injections of 200 ${\mu}L$ fangchinoline every 2 days. Finally, movement of the maxillary first molars was measured using digitized radiographs. The molars were extracted and the surfaces of the root resorption craters were recorded using a scanning electron microscope. The distance the molars moved and resorption-area ratio was measured, and results were analyzed using 2-way ANOVA tests. Results: There were no statistical differences in the distances the first molars moved under 50 or 100 g force, regardless of treatment with fangchinoline. However, the resorption area ratios were significantly smaller in those rats that were treated with both tension and fangchinoline than in those rats treated by tension alone. Conclusions: Fangchinoline reduced the resorption area ratio in rats and is therefore an important means of alleviating root resorption.

• Imaging Science in Dentistry
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• 제40권3호
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• pp.115-121
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• 2010

Purpose : The purpose of this study was to accurately analyze the radiographic characteristics of dentigerous cyst (DC) with multiplanar images of cone beam computed tomography (CBCT). Materials and Methods : Thirty eight radiographically and histopathologically proven cases of DCs were analyzed with panoramic radiograph and CBCT, retrospectively. The radiographic CT pattern, symmetry of radiolucency around the unerupted tooth crown, ratio of long length to short length, degree of cortical bone alternation, effects on adjacent tooth, and cyst size were analyzed. Relative frequencies of these radiographic features were evaluated. In order to compare the CBCT features of DC with those of odontogenic keratocyst (OKC), 9 cases of OKCs were analyzed with the same method radiographically. Results : DCs consisted of thirty unilocular cases (79.0%), seven lobulated cases (18.4%) and one multilocular case (2.6%). Eight were asymmetric (21.0%) and thirty were symmetric (79.0%). Maxillary DC showed rounder shape than mandibular DC (L/S ratio; maxilla 1.32, mandible 1.67). Alternations of lingual cortical bone (14 cases, 48.2%) were more frequent than those of buccal side (7 cases, 24.1%). CBCT images of DC showed definite root resorption and bucco-lingual tooth displacement. These findings were hardly observed on panoramic radiographs of DCs. Comparison of CBCT features of DC with those of OKC showed several different features. Conclusions : CBCT images of DC showed various characteristic radiographic features. Therefore, CBCT can be helpful for the diagnosis of DC radiographically.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.10.1-10.11
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• 2019

Objectives: The objective of this study was to assess coronal discoloration induced by the following intracanal medicaments: calcium hydroxide (CH), a mixture of CH paste and chlorhexidine gel (CH/CHX), and triple antibiotic paste (3Mix). Materials and Methods: Seventy extracted single-canal teeth were selected. Access cavities were prepared and each canal was instrumented with a rotary ProTaper system. The specimens were randomly assigned to CH, CH/CHX, and 3Mix paste experimental groups (n = 20 each) or a control group (n = 10). Each experimental group was randomly divided into 2 subgroups (A and B). In subgroup A, medicaments were only applied to the root canals, while in subgroup B, the root canals were completely filled with medicaments and a cotton pellet dipped in medicament was also placed in the pulp chamber. Spectrophotometric readings were obtained from the mid-buccal surface of the tooth crowns immediately after placing the medicaments (T1) and at 1 week (T2), 1 month (T3), and 3 months (T4) after filling. The ${\Delta}E$ was then calculated. Data were analyzed using 2-way analysis of variance (ANOVA), 3-way ANOVA, and the $Scheff{\acute{e}}$ post hoc test. Results: The greatest color change (${\Delta}E$) was observed at 3 months (p < 0.0001) and in 3Mix subgroup B (p = 0.0057). No significant color change occurred in the CH (p = 0.7865) or CH/CHX (p = 0.1367) groups over time, but the 3Mix group showed a significant ${\Delta}E$ (p = 0.0164). Conclusion: Intracanal medicaments may induce tooth discoloration. Use of 3Mix must be short and it must be carefully applied only to the root canals; the access cavity should be thoroughly cleaned afterwards.

• 대한치과보철학회지
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• 제52권3호
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• pp.165-176
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• 2014

목적: 상아질 지각과민증의 치료를 위해 사용되는 지각과민 처치제의 효과는 일시적인 것으로 보이며 이는 상당부분 칫솔질에 의한 마모소실로 판단된다. 지각과민 처치제의 칫솔질에 의한 마모를 감소시키기 위해 bonding resin을 지각과민 처치제에 추가 도포하여 칫솔질 시행 후 상아질 투과도의 변화에 대해 연구하였다. 재료 및 방법: 우식이 없는 치아를 이용하여 1 mm 두께의 치관부 상아질 디스크를 제작한 다음, All-Bond 2$^{(R)}$, Seal & Protect$^{(R)}$, Gluma$^{(R)}$, MS Coat$^{(R)}$의 4 종류의 지각과민 처치제만 처리한 시편과 Dentine/Enamel Bonding Resin$^{(R)}$ (Bisco Inc.)을 추가로 도포한 시편에 대해 처리하기 전과 처리한 후, 1주(왕복 140회), 2주(왕복 280회), 6주(왕복 840회)에 해당하는 칫솔질을 적용한 후에 측정한 hydraulic conductance (Lp)와 주사 전자 현미경 사진을 비교 분석하였다. 결과: 지각과민 처치제 만을 처리한 군과 bonding resin (Dentine/Enamel Bonding Resin$^{(R)}$)을 추가 도포한 군 모두에서 처리 직후 hydraulic conductance가 급격히 감소하였다. 지각과민 처치제만 처리한 군과 bonding resin을 추가 도포한 군 간의 hydraulic conductance를 비교한 결과 All-Bond 2$^{(R)}$, Gluma$^{(R)}$, MS Coat$^{(R)}$와 bonding resin을 도포한 군에서는 1주(왕복 140회), 2주(왕복 280회), 6주(왕복 840회)의 칫솔질을 시행한 후 hydraulic conductance가 지각과민 처치제만 도포한 군에 비해 현저히 낮았고, Seal & Protect$^{(R)}$ 에서는 6주(왕복840회)의 칫솔질을 시행한 후에만 같은 결과를 보였다. 주사 전자 현미경 관찰에서 지각과민 처치제만 처리한 군과 bonding resin을 추가로 도포한 군 모두에서 처리 직후에 상아세관이 완전히 폐쇄되거나 일부만 폐쇄되어 상아 세관의 내경이 감소된 양상을 볼 수 있었으나, 6주(왕복 840회) 칫솔질 시행 후에는 bonding resin을 추가 도포한 군에서만 현저하게 폐쇄 또는 내경이 감소된 상아세관이 관찰되었다. 결론: 지각과민 처치제 처리 후 bonding resin (Dentine/Enamel Bonding Resin$^{(R)}$, Bisco Inc.)을 추가 도포하는 것이 지속적인 상아세관 폐쇄에 효과적임을 알 수 있었다.