• Journal of dental hygiene science
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• v.12 no.6
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• pp.566-571
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• 2012

Marginal and internal fit are very important factor for the clinical long-term success of fixed dental prostheses (FDPs). A variety of methods have been applied to the measuring marginal and internal fit of FDPs. The purpose of this study was to compare the marginal and internal fit of 2 different measuring methods silicone replica technique [SRT] and die cutting technique (DCT). SRT, the space between die and FDPs were filled with light-body silicone, then stabilized by medium-body silicone. DCT, the FDPs were cemented on definitive dies and embedded into epoxy. The silicone replicas and epoxies were sectioned mesio-distal and measured 4 locations (margin, rounded chamfer, axial, occlusal) and using a digital microscope at a magnification $\times$160. For the SRT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $88.7{\pm}22.2$, rounded chamfer $90.6{\pm}25.0$, axial wall $61.5{\pm}21.8$, occlusal $134.9{\pm}30.8$. For the DCT the mean${\pm}$SDs fit (${\mu}m$) recorded were: margin $85.3{\pm}18.0$, rounded chamfer $85.4{\pm}24.7$, axial wall $62.0{\pm}21.3$, occlusal $131.7{\pm}30.5$. The mean${\pm}$SDs size (${\mu}m$) of SRT margin was $88.7{\pm}22.2$ and of DCT margin was $85.3{\pm}18.0$. There were no statistically significant difference (p<0.05) of the four parts between SRT and DCT. It is considered an appropriate case to use SRT at fit of FDPs.

• Journal of Information Technology Services
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• v.17 no.4
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• pp.1-19
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• 2018

Effective internal communication is known to have a positive impact on business performance, but there is a lack of research on the effects of online channels for workplace communication. This study using regression analysis examines how task-technology fit, information richness, self-efficacy, perceived ease of use, and perceived usefulness related to online communication channels affect not only the satisfaction with the tools but also the effectiveness of them. Additionally, we verify how the organizational culture of online and offline communication shows the control effect. As a result, all five variables were positively correlated with internal communication channels satisfaction, and we found that the organizational culture of online and offline communication controls the relationship between online communication channels satisfaction and effectiveness.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.118-125
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• 2013

PURPOSE. The purpose of this study was to evaluate the effect of the span length on the fit of zirconia framework fabricated using CAD/CAM system. MATERIALS AND METHODS. Abutments for single, 4-unit and 6-unit fixed partial prostheses were fabricated. Ten zirconia frameworks were fabricated for each group. The marginal and internal gap were presented by means of replica technique and measured by measuring microscope ($AXIO^{(R)}$, Carl Zeiss, Rochester, NY) and software (I-$solution^{(R)}$, IMT i-solution Inc., Vancouver, BC, Canada). The results were statistically analyzed by multivariate analysis test and Dunnett T3 test for post hoc test (${\alpha}$=.05). RESULTS. There were statistically significant differences at 2, 4, 7, 8 points (mesio-distal section) and b, d, e, f, g (labio-lingual section). In some marginal reference points of 6-unit group (P<.05), the marginal gap were larger than 120 ${\mu}m$. CONCLUSION. Span length of zirconia core may have an influence on marginal and internal fit. Within the limitation of this study, the increase of span length of zirconia framework of 6 or more-unit fixed partial denture may decrease the marginal and internal fit.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.421-431
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• 2006

Statement of problem : Accurate impression is essential to success of implant prostheses. But there have been few studies about the accuracy of fixture-level impression technique in internal connection implant system. Purpose: This study evaluated the accuracy of splinted fixture-level impression technique using clinical methods and the effect of internal hex on fit of superstructure in internal connection implant system (Astra Tech). Material and method : Two metal master frameworks made from two abutments (Cast-to Abutment ST) each for parallel and divergent conditions and a corresponding. passively fitting, dental stone master cast with four future replicas (Fixture Replica ST) were fabricated. Ten dental stone casts were made with vinyl polysiloxane impressions from the master cast by acrylic resin splinted fixture-level impression technique. To evaluate the accuracy of impression technique, the fit of master frameworks for test models was evaluated using screw resistance test (SRT) and one-screw test. The results of SRT were recorded as SRT values from grade 1 to grade 5 by 1/4 turn. And to evaluate the effect of hex on fit of superstructure, the same tests were performed after removing hexes of master frameworks. Results: 1. There was only one case (2.5%) showing SRT value of test model below ade 2 in total before and after removing hexes of master frameworks. And, by removing hexes. SRT values decreased in only one test model (5%) and did not change in 17 test models (85%). 2. SRT values of the 1$^{st}$ screws were grade 2 in 80% of cases before, and grade 1 in 80% of cases after removing hexes. And, by removing hexes, SRT values decreased in 72.5% of cases. 3. SRT values of the 2$^{nd}$ screws were grade 3 in 85% of cases before, and grade 3 in 95% of cases after removing hexes. And, by removing hexes, SRT values did not change in 85% of cases. 4. There were only 2 cases regarded as acceptable fit by one-screw test, and SRT values of 2$^{nd}$ screws of both cases were grade 2. Conclusion. Within the limitations of this study, future-level impression of internal connection implant system is considered to obtain inaccurate working cast, even using acrylic resin splinted impression technique. And, it is considered to be unable improve the fit to remove the hexes of implant restoration.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.8
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• pp.1215-1226
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• 2009

This study classifies consumers according to apparel shopping values to find the differences of apparel attributes in accordance to shopping value segments between Korean and Chinese college students. College students from Seoul and Beijing participated in the study and a quota sampling method collected the data. Data from 504 questionnaires is used for the statistical analysis. A factor analysis through, Cronbach's alpha coefficient, ANOVA, and a post-hoc test are conducted. Two factors of apparel shopping values are classified (hedonic shopping values and utilitarian shopping values). Four segments of apparel shopping value were classified (hedonic shopping, low involvement shopping segment, high involvement shopping, and utilitarian shopping). Three factors of apparel attribute are classified (external attributes, internal/aesthetic attributes, and internal/quality attributes). The result indicate that high involvement shopping segments considered all the clothing attributes more importantly than the other three segments. Chinese respondents of hedonic shopping segments and high involvement shopping segments considered advertisements in terms of external attributes, assembly, and fit in terms of internal/quality performance attributes as more important than Koreans. Chinese respondents of low involvement shopping segments also considered assembly and fit in terms of internal/quality performance attributes as more important than Koreans. Korean respondents of utilitarian shopping segments had a special regard for design and color in terms of internal/aesthetic attributes but the Chinese had a special regard for assembly, fit, and ease of maintenance in terms of internal/quality performance attributes.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.271-277
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• 2017

PURPOSE. This in vitro study aimed to evaluate the effect of implant connection design (external vs. internal) on the fit discrepancy and torque loss of zirconia and titanium abutments. MATERIALS AND METHODS. Two regular platform dental implants, one with external connection ($Br{\aa}nemark$, Nobel Biocare AB) and the other with internal connection (Noble Replace, Nobel Biocare AB), were selected. Seven titanium and seven customized zirconia abutments were used for each connection design. Measurements of geometry, marginal discrepancy, and rotational freedom were done using video measuring machine. To measure the torque loss, each abutment was torqued to 35 Ncm and then opened by means of a digital torque wrench. Data were analyzed with two-way ANOVA and t-test at ${\alpha}=0.05$ of significance. RESULTS. There were significant differences in the geometrical measurements and rotational freedom between abutments of two connection groups (P<.001). Also, the results showed significant differences between titanium abutments of internal and external connection implants in terms of rotational freedom (P<.001). Not only customized internal abutments but also customized external abutments did not have the exact geometry of prefabricated abutments (P<.001). However, neither connection type (P=.15) nor abutment material (P=.38) affected torque loss. CONCLUSION. Abutments with internal connection showed less rotational freedom. However, better marginal fit was observed in externally connected abutments. Also, customized abutments with either connection could not duplicate the exact geometry of their corresponding prefabricated abutment. However, neither abutment connection nor material affected torque loss values.

• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.37-43
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• 2016

Objectives: The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. Materials and Methods: A full veneer crown and an mesio-occluso-distal (MOD) inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU) and experimental nano-composite CAD/CAM blocks (EB) under the same milling parameters. To assess the marginal and internal fit, the restorations were cemented to replicas and were embedded in an acrylic mold for sectioning at 0.5 mm intervals. The measured gap data were pooled according to the block types and measuring points for statistical analysis. Results: Both the block type and measuring point significantly affected gap values, and their interaction was significant (p = 0.000). In crowns and inlays made from the two blocks, gap values were significantly larger in the occlusal area than in the axial area, while gap values in the marginal area were smallest (p < 0.001). Among the blocks, the restorations milled from EB had a significantly larger gap at all measuring points than those milled from LU (p = 0.000). Conclusions: The marginal and internal gaps of the two nano-composite CAD/CAM blocks differed according to the measuring points. Among the internal area of the two nano-composite CAD/CAM restorations, occlusal gap data were significantly larger than axial gap data. The EB crowns and inlays had significantly larger gaps than LU restorations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.575-576
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• 2009

• Journal of Korean Academy of Nursing Administration
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• v.11 no.4
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• pp.371-384
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• 2005

Purpose: The aim of this study was to analysis path model of the research variables. Methods: The subjects of this study were 647 nurses who were working in the 8 general hospitals located in Seoul and Incheon area. The data were collected by self-reporting questionnaires. The data were analyzed using descriptive statistics and path analysis. Results: In the modified path model, overall fitness indexes were $X^2$= 223.27, goodness of fit index=0.90, root mean square residual=0.039, root mean square error of approximation=0.12, non-normed fit index=0.96, and normed fit index=0.90. From the model, among research variables that influence organizational effectiveness motivator, job satisfaction and organizational identification affected directly work performance. In internal marketing factors, paid-leave, communication and reward affected directly motivator. Motivator and hygiene factors affected directly job satisfaction, organizational commitment and organizational identification. Conclusion: With these findings, paid-leave, communication, reward, motivator, job satisfaction and organizational identification were direct or indirect predictors of the work performance. Therefore nursing managers ought to develop internal marketing strategies and motivation enhancing system for nurses based on this path model in order to improve the nursing organizational effectiveness.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.5
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• pp.489-500
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• 2004

Statement of problem: The use of zirconia prostheses fabricated with CAD/CAM system is on an increasing trend in dentistry. However, evaluation of the fit related to internal relief and marginal reproducibility of zirconia has not been reported. Purpose : This study was to evaluate the fit related to internal relief and marginal reproducibility of zirconia core fabricated with CAD/CAM system. Materials and methods: The evaluation was based on 30 zirconia cores and 5 IPS-Empress2 cores. Zirconia cores were fabricated in different conditions of internal relief(0, 10, 20, 30, 40 and $50{\mu}m$), and IPS-Empress2 cores were fabricated in accordance with the manufacturer's instructions. Before cementation, the marginal discrepancies or cores were measured on metal die. And then, each core was cemented to stone die, embedded in an acrylic resin and sectioned in two planes(mesiodistally and labiopalatally). The internal gaps were measured at the margin and axial surface. Measurements for the marginal discrepancies, the internal marginal gaps and the internal axial gaps were performed under a measuring microscope(Compact measuring microscope STM5; Olympus, Japan) at a magnification of ${\times}100$. In addition, the marginal conagurations of metal die, zirconia core and IPS-Empress2 core were examined with SEM(S-2700, Hitachi, Japan). Results : Within the limits of this study the results were as follows. 1. Compared with IPS-Empress2 cores, the marginal discrepancies of zirconia cores had no significant differences. the internal marginal gaps were statistically smaller and the internal axial gaps were statistically larger in each condition of internal relief. 2. The marginal discrepancies and the internal marginal gaps of zirconia cores had no significant differences related to the conditions of internal relief(P>0.05). 3. The internal axial gaps of zirconia cores with $0{\sim}20{\mu}$m for internal relief were significantly larger than that with $50{\mu}m$ (P<(0.0001). 4. SEM micrographs showed favorable marginal reproducibility of zirconia core and smooth texture on the milling surface. Conclusion: The marginal discrepancy and the internal gaps of zirconia core were clinically acceptable and the milling surface was showed smooth texture. For fabrication of the durable esthetic restoration, further investigations on complex design of core, milling accuracy, compatability of enamel porcelain and porcelain firing seems to be needed.