• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.6
• /
• pp.724-734
• /
• 2007

Statement of problem. Translucency and masking effect of provisional crown and fixed partial denture materials is an important esthetic consideration. But, provisional resin materials differ substantially in their ability to mask underlying colors. Purpose. The purpose of this study was to evaluate the translucency differences of provisional resin materials at various thicknesses and the correlation between the translucency and the masking efficiency. Material and methods. Two polymethyl methacrylate resins (Jet Tooth Shade, Alike) and three resin composites (Protemp 3 Garant, Luxatemp and Revotek LC) were used. Specimens (n=6) were fabricated from each material in 0.3, 0.5, 0.8, 1.0, 1.5, 2.0 and 3.0 mm thickness. The CIELAB parameters of each specimens were measured using a spectrophotometer. The translucency parameter (TP) values and the masking effect $({\Delta}ME^*{_{ab}})$ values were computed and all data were statistically analyzed by one-way ANOVA and the multiple comparisons Scheffe test. The correlation between the thickness and the TP values and the correlation between the thickness and the ${\Delta}ME^*{_{ab}}$ values were also evaluated by correlation analysis and regression analysis. Results. The TP values and the ${\Delta}ME^*{_{ab}}$ values were significantly related to the thickness in all specimens. The TP values were more sensitive to the change of thickness than the ${\Delta}ME^*{_{ab}}$ values. The order of the translucency by brand was different from the order of the masking effect by brand in all thickness groups. Conclusion. Within the limitations of this study, the translucency and masking effect of the provisional resin materials investigated were significantly related to their thickness. The masking effect of provisional resin was correlated with the translucency parameter, but the order of the masking effect by brand was different from the order of the translucency parameter.

• The Journal of Advanced Prosthodontics
• /
• v.1 no.1
• /
• pp.31-36
• /
• 2009

PURPOSE. To determine the change in stability of single-stage, three different design of implant systems in humans utilizing resonance frequency analysis for early healing period(24 weeks), without loading. MATERIAL AND METHODS. Twenty-five patients were included into this study. A total of 45 implants, three different design of implant systems(group A,C,R) were placed in the posterior maxilla or mandible. The specific transducer for each implant system was used. ISQ(implant stability quotient) reading were obtained for each implant at the time of surgery, 3, 6, 8, 10, 12, 24 weeks postoperatively. Data were analyzed for different implant type, bone type, healing time, anatomical locations. RESULTS. For each implant system, a two-factor mixed-model ANOVA demonstrated that a significant effect on ISQ values(group A=0.0022, C=0.017, R=0.0018). For each implant system, in a two-factor mixed model ANOVA, and two-sample t-test, the main effect of jaw position(P > .005) on ISQ values were not significant. CONCLUSIONS. All the implant groups A, C and R, the change patterns of ISQ over time differed by bone type. Implant stability increased greatly between week 0 and week six and showed slow increase between week six and six months(plateau effect).

• The Journal of Advanced Prosthodontics
• /
• v.5 no.2
• /
• pp.153-160
• /
• 2013

PURPOSE. This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added. MATERIALS AND METHODS. Five groups were formed: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance. RESULTS. In all mechanical tests, the highest values were observed in Valplast group (transverse strength: $117.22{\pm}37.80$ MPa, maximum deflection: $27.55{\pm}1.48$ mm, impact strength: $0.76{\pm}0.03$ kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples. CONCLUSION. Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.

• Journal of the Korea Convergence Society
• /
• v.6 no.2
• /
• pp.37-42
• /
• 2015

Nowadays, as the environmental pollution becomes severe on the earth, the water resource which can be used practically is dried up because of the natural disaster. And so, this is the time to be necessary to have the method for saving the water resource. This study investigates the distributions of velocity and temperature by the flow analysis inside the faucet models for bathroom. Model 3 has the most uniform distribution of temperature after mixing among all models. As model 3 has the smallest velocity distribution and the biggest space to mix by comparing the other models, it is seen to have the most influence on the discharged velocity of water and save the water. As the space of various configuration inside faucet model for bathroom is made by using the result of this study, it is thought to utilize at the development of this model in which more mixing becomes and the water can be saved. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• Archives of Plastic Surgery
• /
• v.51 no.1
• /
• pp.30-35
• /
• 2024

Background Breast aesthetics evaluation often relies on subjective assessments, leading to the need for objective, automated tools. We developed the Seoul Breast Esthetic Scoring Tool (S-BEST), a photometric analysis software that utilizes a DenseNet-264 deep learning model to automatically evaluate breast landmarks and asymmetry indices. Methods S-BEST was trained on a dataset of frontal breast photographs annotated with 30 specific landmarks, divided into an 80-20 training-validation split. The software requires the distances of sternal notch to nipple or nipple-to-nipple as input and performs image preprocessing steps, including ratio correction and 8-bit normalization. Breast asymmetry indices and centimeter-based measurements are provided as the output. The accuracy of S-BEST was validated using a paired t-test and Bland-Altman plots, comparing its measurements to those obtained from physical examinations of 100 females diagnosed with breast cancer. Results S-BEST demonstrated high accuracy in automatic landmark localization, with most distances showing no statistically significant difference compared with physical measurements. However, the nipple to inframammary fold distance showed a significant bias, with a coefficient of determination ranging from 0.3787 to 0.4234 for the left and right sides, respectively. Conclusion S-BEST provides a fast, reliable, and automated approach for breast aesthetic evaluation based on 2D frontal photographs. While limited by its inability to capture volumetric attributes or multiple viewpoints, it serves as an accessible tool for both clinical and research applications.

• Journal of Periodontal and Implant Science
• /
• v.23 no.3
• /
• pp.400-410
• /
• 1993

Dental implants have been widely used in the treatment of esthetic and functional problems of the mouth due to alveolar bone loss, after tooth extraction. The success of implantation strongly depends on osseointegration. For osseointegration, implant material, methodology, and design have been investigated. For materials, two popular materials at present are titanium and hydroxyapatite. For methods, immediate implantation is being used recently. The purpose of this study is to evaluate osseointegration between the unthreaded cylindrical TPS implant and the HA-coated implant by a histomorphometric analysis. For this analysis, experimental periodontits was induced on the 3, 4 premolars of adult dogs by the ligation of orthodontic threads. Thereafter, each tooth was extracted. TPS. Implants and HA-coated implants were immediately inserted in the extraction socket. In control group, TPS implants were immediately inserted, and In experimental group, HA implants were immediately inserted. The dogs were sacrificed after 12 weeks, then the specimens were prepared for LM and histomorphometric analysis. The conclusion of this study is as follows l. In both control and experimental group, no inflammatory cells were observed. 2. The results of the histomorphometric analysis showed that the total osseointegration was 48.5% in control group, and 68.8% in expermental group. The experimental group was higher than the control group, and the difference was not statistically significant (p<0.05). 3. The results of the histomorphometric analysis showed that the osseointegration in the hole was 40.6% in control group, and 70.2% in experimental group. The experimental group was higher than the control group, and the difference was statistically significant (p<0.05). In both control and experinental group, no inflammatory cells were observed. 4. The results of the histomorphometric analysis showed that the osseointegration in the lower part was 52.1% in control group, and 73.3% in experimental group. The experimental group was higher than the control group, and the difference was statistically significant (p<0.05). 5. In experimental group, the bone to HA interface seemed to be mixed of bone and HA. We could not distinguish HA from the bone. The HA coating was detached from the titanium surface.

• Journal of the Korea Convergence Society
• /
• v.7 no.1
• /
• pp.161-166
• /
• 2016

Deformation, stress and fatigue life due to the configuration of tie rod end are investigated in this study. Tie rod ends with the total three kinds of configurations are modelled with three dimensions through CATIA program and the simulation analysis is carried out with the ANSYS finite element analysis program. There are the models of A, B and C by the configuration of the rod end. As this study result, maximum deformation, maximum equivalent stress and maximum fatigue life of A type model are shown to be 0.0614mm, 160.27MPa and 336,930cycles respectively. And maximum deformation, maximum equivalent stress and maximum fatigue life of B type model are shown to be 0.0648mm, 90.889MPa and 1,171,000cycles respectively. Maximum deformation, maximum equivalent stree and maximum fatigue life of C type model are also shown to be 0.0402mm, 84.794MPa and 20,000,000cycles respectively. The durability of the models of tie rod ends through the values of this result could be estimated and the data for the design and development of more improved tie rod end could be secured. And it is possible to be grafted onto the convergence technique at design and be shown as the esthetic sense.

• Journal of the Korea Convergence Society
• /
• v.6 no.4
• /
• pp.99-105
• /
• 2015

In order to prevent the environmental pollution nowadays, the mobile device for one person of cruiser board not used with the fossil oil has been noticed. This study aims to analyze the property of cruiser board due to the shape by carrying out the structural analysis for the safe design of cruiser board. Two models of the existing cruiser board and the cruiser board with new configuration are designed. As the structural analysis was carried out by using the finite element analysis program, the durability by deformation, stress and fatigue life was investigated. In the study result, the model of cruiser board with new configuration has the maximum deformation of 0.000971mm, the maximum stress of 0.936MPa and the fatigue life from 1827.7Cycle to $1.887{\times}105Cycle$. As all study result values at the new model became better than the existing model, the new model was seen to become more adequate at using than the existing model. This study result can be contributed to the safer and durable design of cruiser board. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• Journal of Technologic Dentistry
• /
• v.31 no.4
• /
• pp.55-66
• /
• 2009

This research collected the curriculum for Dental Technology from a total of 20 schools --3-year colleges and 4-year colleges-- all in Korea. And we analyzed the average credits of subjects from students. As a result of this analysis, we get the conclusion below: 1. In the arithmetic mean of the major basis subjects which graduates and undergraduates answered about each subjects; Seminar, Dental morphology I II, Dental morphology practice I II, and Dental devices & instruments don't have many credits. And averages of the major application subjects credits which are Implants(especially low), Occlusal anatomy practice I II, Dental ceramics practice I II, and Dental ceramics practice are low, mostly have a converged tendency in high points. 2. In an analysis of the correlation which is based on the major basis subjects: Dental esthetic, oral anatomy I II, Dental materal practice III, Dental casting pracedure, Oral hygiene, Health & medical law, Management administration, and Medical terminology have a meaningful difference. (${\rho}$ < 0.05) 3. In an analysis of the correlation which is based on the major application subjects; Crown and bridge prosthodontics practice IV, Complete denture prosthodontics I II III, Complete denture prosthodontics practice I II III, Dental ceramics I II, Dental ceramics practice I II, Dental ceramics practice IIII, Occlusal anatomy I II, Occlusal anatomy practice I, Operative dentistry laboratory technology I, Operative dentistry laboratory technology practice II, Dental attachment laboratory technology practice, Implants, and Dental laboratory clinical practice have meaningful difference. (${\rho}$ < 0.05) 4. In an analysis of the correlation which is based on the ratio of a theory to an actual training; 40:60(38.57%) is the highest, followed by 30:70(30.04%), 50:50(23.32%), 60:40(5.83%), and 70:30(2.24%). These have meaningful difference. (${\rho}$ < 0.05) 5. In an analysis of the correlation which is based on the distinction of sex: Partial denture prosthodontics practice I II III, Complete denture prosthodontics I II III, Complete denture prosthodontics practice I II III, Occlusal anatomy practice I II, Implants, Medical terminology have meaningful difference. (${\rho}$ < 0.05) For the purpose of training entrepreneurs of middle standing who is required by a future society, Department of Dental Technology's Curriculum need to be managed with planning a curriculum which reflects opinions of graduates, undergraduates and a society, and also are considered not focusing on a supplier but focusing on a user.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.29 no.3_4 s.141
• /
• pp.523-534
• /
• 2005

This study was to examine the factor structure of pursuing benefit and satisfaction at casual and official wear, to analyze the differences of pursuing benefit, satisfaction, and clothing purchase behavior among the consumer groups segmented by store pursuing benefits, and to provide useful information for establishment of marketing strategies. The subjects were 500 female consumers experienced in purchasing clothes at fashion outlet stores. A total of 500 questionnaires were analyzed with $X^2$-test, ANOVA, factor analysis and Duncan's multiple range test. The results were as follows: 1. Pursuing benefit and satisfaction at casual wear and official wear were composed of 5 factors. 2. Pursuing benefit and satisfaction at casual and offcial wear, and clothing purchasing behavior variables such as informants, frequency of purchase, shopping time, and average monthly expenditure on clothes were significantly different among the 3 segmented groups. Product pursuing group was shown to seek higher level of esthetic feeling, suitability for self image and body, fsshion and symbolic meaning of brand than other groups in casual and official wear and to be most satisfied at symbolic meaning of brand, social recognition, and practicality in casual wear of outlet and at suitability and social recognition in official wear of outlet. Store convenience pursuing group was shown to seek higher level of suitability for self image and body, quality, and practicality than other groups in casual and official wear and to be most satisfied at quality and practicality in casual wear of outlet and at practicality and suitability in of cial wear of outlet. Price pursuing group was shown to seek and to be most satisfied at practicality in casual and official wear of outlet.