• The Journal of Korean Academy of Prosthodontics
• /
• v.57 no.4
• /
• pp.350-355
• /
• 2019

For the success of complete denture, three essential requirements such as retention, stability and support are needed. Moreover, due to the absorption of residual ridge and scarring due to the surgery, when making a complete denture, which is difficult to form the mandibular lingual margins, various considerations such as the arrangement of the Non-anatomical dl non-anatomical teeth, the polished surface impression, the internally weighted metal framework and the use of the denture adhesive cream are necessary. In this case report, the patient has a severely resorbed edentulous ridge from severe periodontitis and has some soft tissue problems after the glossectomy due to tongue cancer. To obtain additional retention and stability, some trials such as polished surface impression taking, internally weighted metal insertion and minimal pressure impression were done for the better result. Moreover To make a metal framework that precisely shapes the desired three-dimensional shape and reduces the complicated process, minimal pressure impression method and direct metal laser sintering technique were used.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.693-700
• /
• 2020

This study compared the accuracy and reliability of definitive casts fabricated from a digital impression and conventional impression technique. A master model with the prepared upper full-arch tooth was used. Samples of ten plaster models and ten polyurethane models were duplicated using a selected standard master model. Six linear measurements were recorded between the landmarks, directly on each of the stone models and the polyurethane models on two occasions by a double examiner. The Wilcoxon signed-rank test, interclass correlation coefficient (ICC), measurement error (MSE), and limit of agreement (LoA) were used for statistical analysis. The ICC ranged from 0.76 to 0.99 when comparing the stone models and polyurethane models. The mean difference between the stone models and polyurethane models ranged from 0.09mm to 0.20mm, suggesting that stone models might be slightly larger than polyurethane models. Based on this study, the accuracy of the polyurethane models in evaluating the performance of an oral scanner and subtractive technology was acceptable. Further studies will be needed on patient subjects under clinical conditions that may involve missing or malpositioned teeth and fixed dental prostheses because this study was limited to use a standard master model and duplicated sample models in a laboratory setting.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.459-468
• /
• 2021

In patients with myasthenia gravis, it is difficult to manufacture and maintain dentures because the muscles and nervous system in the oral cavity are not properly adjusted. In addition, excessively extended or thick dentures may cause muscle weakness by stimulating the muscles, so dentures should be manufactured in consideration of this. In this case, a denture was fabricated using the closed mouth technique in a patient with myasthenia gravis with mouth opening limitation. Using the closed mouth technique, the patient's masticatory pressure and muscle movements were reproduced and denture with good retention were manufactured.

• Journal of architectural history
• /
• v.25 no.5
• /
• pp.15-25
• /
• 2016

The color that painted on the ground of Dancheong becomes Gachil(basecoat)-Dancheong and underpainting of Moro-Dancheong or Geum-Dancheong. So, the color of underpainting is the most important element that determines impression of the building. Thus, the architecture after using "Sangrokhadan" has different characters from what it had been. In the existing perception toward the background color of Dancheong, it was considered the characters of Korean Dancheong so-called "Sangrokhadan" that paint vertical elements like columns red and upper part of the columns green. But this study examined the color of Dancheong according to the era and region before and after Goryeo Dynasty era, then it reveals that Sangrokhadan technique was applied from the 14th century in the late Goryeo Dynasty. One of the Goryeo architecture, Geungnakjeon Hall of Bongjeongsa Temple is thought to be a previous style that is not applied "Sangrokhadan" technique because old elements are painted red pigment.

• The Journal of Advanced Prosthodontics
• /
• v.6 no.1
• /
• pp.1-7
• /
• 2014

PURPOSE. The accuracy of a gypsum model (GM), which was taken using a conventional silicone impression technique, was compared with that of a polyurethane model (PM), which was taken using an iTero$^{TM}$ digital impression system. MATERIALS AND METHODS. The maxillary first molar artificial tooth was selected as the reference tooth. The GMs were fabricated through a silicone impression of a reference tooth, and PMs were fabricated by a digital impression (n=9, in each group). The reference tooth and experimental models were scanned using a 3 shape convince$^{TM}$ scan system. Each GM and PM image was superimposed on the registered reference model (RM) and 2D images were obtained. The discrepancies of the points registered on the superimposed images were measured and defined as GM-RM group and PM-RM group. Statistical analysis was performed using a Student's T-test (${\alpha}=0.05$). RESULTS. A comparison of the absolute value of the discrepancy revealed a significant difference between the two groups only at the occlusal surface. The GM group showed a smaller mean discrepancy than the PM group. Significant differences in the GM-RM group and PM-RM group were observed in the margins (point a and f), mesial mid-axial wall (point b) and occlusal surfaces (point c and d). CONCLUSION. Under the conditions examined, the digitally fabricated polyurethane model showed a tendency for a reduced size in the margin than the reference tooth. The conventional gypsum model showed a smaller discrepancy on the occlusal surface than the polyurethane model.

• The International Journal of Costume Culture
• /
• v.12 no.2
• /
• pp.163-178
• /
• 2009

Fashion pictorials are recognized as another form of communication method beyond the concept of simply providing information or being artistic photography. Therefore, it is believed that there is necessity to know methods of making a strong impression on people's conscience by effective usage of various presentation techniques that can be used in fashion pictorials. This research studied characteristics of closed form and open form of Wolfflin's precept of forms presented in scene construction. Depaysement technique was classified into three classes which are alien transportation of a part, deformation and ambivalence of an image through literature review of depaysement presentation technique. After studying the concept and characteristics of narrative applicable as the open form, Annie Leibovitz's "Alice's Adventures in Wonderland" published in an actual fashion magazine was analyzed as an empirical study based on the theoretical research. Through this study, potential of applying depaysement technique as a presentation technique of closed form and narrative as a presentation technique of open form on fashion pictorials was identified. Factors that infuse creativity and achieve uniformity in producing fashion pictorials were shown through analysis of actual fashion pictorials.

• The Journal of Advanced Prosthodontics
• /
• v.13 no.5
• /
• pp.316-326
• /
• 2021

PURPOSE. Purpose of this in vitro study was to determine the accuracy of different intraoral scans versus laboratory scans of impressions and casts for the digitization of an edentulous maxilla. MATERIALS AND METHODS. A PEEK model of an edentulous maxilla, featuring four hemispheres on the alveolar ridges in region 13, 17, 23 and 27, was industrially digitized to obtain a reference dataset (REF). Intraoral scans using Cerec Primescan AC (PRI) and Cerec AC Omnicam (OMN), as well as conventional impressions (scannable polyvinyl siloxane) were carried out (n = 25). Conventional impressions (E5I) and referring plaster casts were scanned with the inEOS X5 (E5M). All datasets were exported in STL and analyzed (Geomagic Qualify). Linear and angular differences were evaluated by virtually constructed measurement points in the centers of the hemispheres (P13, P17, P23, P27) and lines between the points (P17-P13, P17-P23, P17-P27). Kolmogorov-Smirnov test and Shapiro-Wilk test were performed to test for normal distribution, Kruskal-Wallis-H test, and Mann-Whitney-U test to detect significant differences in trueness, followed by 2-sample Kolmogorov-Smirnov test to detect significant differences in precision (P < .008). RESULTS. Group PRI showed the highest trueness in linear and angular parameters (P < .001), while group E5I showed the highest precision (P < .001). CONCLUSION. Intraoral scan data obtained using Primescan showed the highest trueness while the indirect digitization of impressions showed the highest precision. To enhance the workflow, indirect digitization of the impression itself appears to be a reasonable technique, as it combines fast access to the digital workflow with the possibility of functional impression of mucosal areas.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.2
• /
• pp.220-227
• /
• 2021

A patient failed to use conventional complete dentures due to severe mandibular bone resorption and soft tissue hyperplasia on lips, tongue and oral vestibule from vascular malformation. The treatment of choice would be an implant-retained overdenture, however, he refused owing to high cost. The closed mouth impression technique using BPS principle, CR record registration with gothic arch tracing and monoplane occlusion using non-anatomic teeth were used to fabricate complete dentures for this patient. Patient satisfaction, the retention and the stability of complete dentures were highly improved as a result.

• The Journal of Advanced Prosthodontics
• /
• v.15 no.6
• /
• pp.315-332
• /
• 2023

PURPOSE. This study aimed to investigate whether the accuracy of intraoral scanners is influenced by different scanning strategies in an in vitro setting, through a systematic review and meta-analysis. MATERIALS AND METHODS. This review was conducted in accordance with the PRISMA 2020 standard. The following PICOS approach was used: population, tooth impressions; intervention, the use of intraoral scanners with scanning strategies different from the manufacturer's instructions; control, the use of intraoral scanners following the manufacturers' requirements; outcome, accuracy of intraoral scanners; type of studies, in vitro. A comprehensive literature search was conducted across various databases including Embase, SciELO, PubMed, Scopus, and Web of Science. The inclusion criteria were based on in vitro studies that reported the accuracy of digital impressions using intraoral scanners. Analysis was performed using Review Manager software (version 5.3.5; Cochrane Collaboration, Copenhagen, Denmark). Global comparisons were made using a standardized mean difference based on random-effect models, with a significance level of α = 0.05. RESULTS. The meta-analysis included 15 articles. Digital impression accuracy significantly improved under dry conditions (P < 0.001). Moreover, trueness and precision were enhanced when artificial landmarks were used (P ≤ 0.02) and when an S-shaped pattern was followed (P ≤ 0.01). However, the type of light used did not have a significant impact on the accuracy of the digital intraoral scanners (P ≥ 0.16). CONCLUSION. The accuracy of digital intraoral scanners can be enhanced by employing scanning processes using artificial landmarks and digital impressions under dry conditions.

• The Journal of Advanced Prosthodontics
• /
• v.11 no.2
• /
• pp.138-146
• /
• 2019

PURPOSE. Comparing the accuracy of casts produced from digital workflow to that of casts produced from conventional techniques. MATERIALS AND METHODS. Whole arch alginate (ALG) and polyvinyl siloxane (PVS) impressions were taken with stock trays and custom trays, respectively. The ALG impressions were poured with type III dental stone, while the PVS impressions were poured with type IV dental stone. For the digital workflow, IOS impressions were taken and physical casts were produced by 3D printing. In addition, 3D printed casts were produced from images obtained from a laboratory scanner (LS). For each technique, a total of 10 casts were produced. The accuracies of the whole arch and separated teeth were virtually quantified. RESULTS. Whole arch cast accuracy was more superior for PVS followed by LS, ALG, and IOS. The PVS and ALG groups were inferior in the areas more susceptible to impression material distortion, such as fossae and undercut regions. The LS casts appeared to have generalized errors of minor magnitude influencing primarily the posterior teeth. The IOS casts were considerably more affected at the posterior region. On the contrary, the IOS and LS casts were more superior for single tooth accuracy followed by PVS and ALG. CONCLUSION. For whole arch accuracy, casts produced from IOS were inferior to those produced from PVS and ALG. The inferior outcome of IOS appears to be related to the span of scanning. For single tooth accuracy, IOS showed superior accuracy compared to conventional impressions.