• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.86-94
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• 2020

Purpose: The purpose of this study is to compare the volume stability depending on the mixing methods and storage time for the conventional alginate and extended-pour alginate. Materials and methods: An arch-shaped metal model was fabricated, and one conventional alginate and two extended-pour alginates were used to take impressions using different mixing methods (hand and automatic). 120 impressions were taken (40 per each alginate) and stone models were made in accordance with the different storage times (immediate, 2 days, 5 days, and 6 days). The models were scanned with a 3D table scanner and dimensional change was measured by superimposing the scan data. Using SAS 9.4 (SAS Institute Inc., Cary, NC, USA), the general linear model and Tukey's post hoc test was conducted for statistical analysis (P<.001). Results: There was no statistically significant difference in the dimensional accuracy between two mixing methods, and the volume change was minimum when the stone was poured immediately in all groups. Dimensional accuracy showed a statistically significant difference between groups after 2 days of storage, and extended-pour alginate showed higher accuracy after 5 days of storage comparing to conventional one. Large amounts of volume change were showed at 2 - 5 days for conventional alginate and at 5 - 6 days for extended pour alginate. Conclusion: The mixing method of alginate does not affect volume stability. Although extended-pour alginate has better volume stability than conventional alginate for a long time, it is recommended to pour stone as soon as possible.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.270-279
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• 2018

Purpose: The aim of this study was to assess the patients' perception, acceptance, and preference of the difference between a conventional impression and digital impression through questionnaire survey. Materials and Methods: Thirteen (6 male, 7 female) subjects who experienced both digital and conventional impression at the same day were enrolled in this study. Conventional impression were taken with polyvinylsiloxane and digital impression were performed using a newly developed intra-oral scanner. Immediately after the two impressions were made, a survey was conducted with the standardized questionnaires consisting of the following three categories; 1) general dental treatment 2) satisfaction of conventional impression 3) satisfaction of digital impression. The perceived source of satisfaction was evaluated using Likert scale. The distribution of the answers was assessed by percentages and statistical analyses were performed with the paired t-test, and P < 0.05 was considered significant. Results: There were significant differences of the overall satisfaction between two impression methods (P < 0.05). Digital impression showed high satisfaction in less shortness of breath and odor to participants compared to conventional impression. The use of an oral scanner resulted in a discomfort of TMJ due to prolonged mouth opening and in lower score of the scanner tip size. Conclusion: It was confirmed that the preference for the digital impression using intraoral scanner is higher than the conventional impression. Most survey participants said they would recommend the digital impression to others and said they preferred it for future prosthetic treatment.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.246-253
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• 2022

Flabby tissue is not rare for denture wearers. Mucostatic impression technique is necessary due to compromised retention and stability of denture resulting from distortion of mobile flabby tissue. In this report, individual tray was fabricated by model-scanning and 3D printing treatment denture. And then, mucostatic impression for flabby tissue was obtained by using individual tray modified with window technique. Definitive denture was fabricated based on information of treatment denture including incisal pontic arrangement, jaw relationship and occlusion.

• KDI Journal of Economic Policy
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• v.19 no.3
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• pp.195-246
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• 1997

우리나라에서 전기요금은 공공요금으로서 정부의 정책의지에 의하여 크게 영향을 받아왔다. 또한 전기요금수준 조정시 규제당국의 주된 관심은 요금인상이 국민경제에 미치는 영향, 특히 물가 및 무역수지에 미치는 영향에 있었다고 할 수 있다. 이러한 상황에서 전기요금변동의 국민경제적 영향에 대한 신뢰할 수 있는 분석결과는 올바른 정책수립에 필수적이라고 할 수 있다. 본고는 계산가능한 일반균형모형(Computable General Equilibrium model)을 이용하여 1993년도의 산업연관표를 토대로 전기요금의 인상이 물가, 수출입 등 거시변수에 미치는 효과 및 산업부문별 효과를 살펴본 것이다. 전기요금인상이 물가에 미치는 영향은 간단히 '전기요금인상률${\times}$물가가중치'라는 공식으로 계산해볼 수 있다. 이에 따르면 전기의 소비자물가 가중치가 14/1,000이므로 전기요금인상률이 4%일 때 소비자물가상승률은 약 0.056%가 된다. 그러나 전기가 타산업의 중간투입물로 사용되므로 전기요금인상은 타산업 산출물의 가격상승을 유발하고 다시 투입-산출관계에 의하여 추가적인 물가상승을 불러일으키게 된다. 이러한 일반균형적 효과를 모두 고려하여, 본 연구에서 계산한 소비자물가상승률은 0.083%로서 위 수치의 약 1.5배이다. 또한 본고에서는 전기요금인상에 따라 수출과 수입 모두 감소하되, 수출감소율이 수입감소율보다 크게 나타났다. 이러한 결과는 전기요금인상에 따라 전기수요가 감소하여 에너지수입이 감소하고, 그로 인해 무역수지가 개선되리라는 일부의 주장과는 매우 대조적이다. 산업별로는 전기요금인상에 따라 서비스업의 가격상승이 두드러지는 것으로 나타났는데, 이는 서비스업부문의 국내재와 수입재간의 대체가능성이 타부문에 비하여 크게 낮은 데 기인한 것으로 보인다. 본고의 결과를 전기요금이 인상되어서는 안 된다고 해석하는 것은 오류일 수 있다. 전기요금인상의 타당성은 전력산업에 대한 종합적인 미시적 분석에 기초하여야 한다.

• 대한치과보철학회:학술대회논문집
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• 1998.11a
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• pp.24-24
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• 1998

• Proceedings of the Korean Vacuum Society Conference
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• 1999.02a
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• pp.29-29
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• 1999

• The Journal of the Korean dental association
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• v.3 no.1
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• pp.37-39
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• 1961

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.221-225
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• 2012

Disc dislocation without reduction, as known as closed lock, is a clinical condition in which the disc is dislocated from the condyle and does not return to normal position during condylar movement When the condition of disc dislocation without reduction is acute, the initial therapy should include an attempt to reduce or recapture the disc by manual manipulation. When patients report a history of being locked for 1 week or less, manual manipulation is usually successful. In patients with a longer history, success rate tends to decrease rapidly. If the disc has been successfully recaptured, placing an anterior positioning appliance is recommended to prevent clenching on the posterior teeth, which would likely redislocated the disc. But it is hard to make an appliance immediately in the clinic because it takes too much time. And making an appliance using self-curing acrylic resin is not very popular because of its discomfort by odor and working time. Also, if the patient has resin allergy or is under orthodontic treatment, or if it is impossible to control behavior of the patient, it has been restricted to make an appliance immediately. Therefore, to supplement this disadvantages, we tried to confirm about successful short term use of temporary anterior positioning splint made by using putty impression material after manual manipulation in this study.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.369-379
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• 2009

This study investigated the polymerization inhibition effect of latex gloves on addition silicone impression material. Three different kinds of addition silicone impression materials and a natural latex gloves were used in this study. The results were as follows. 1. Compared to the control group, all of those three kinds of impression materials took longer curing time in order of unwashed, alcohol and washed group, on the other hand, degloving group had shorter curing time than control group(p<0.05). 2. By the type of impression materials, there was no significant difference observed between Exafine and Twinz in ungloved group, Exafine and Imprint II in unwashed group, and Exafine and Twinz in degloving group(p>0.05). 3. The degree of polymerization at 6 minutes after mixing impression materials was evaluated by dividing its range into score 1 to 5. All of the impression materials got score 5 in control group and degloving group, which implies perfect polymerization. In unwashed group, most of them appeared to be score 2 while score 3 were most frequently observed in alcohol group and score 4 in washed group. Thus each group showed differences in the degree of polymerization(p<0.05).

• Journal of dental hygiene science
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• v.14 no.1
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• pp.15-21
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• 2014

The purpose of this study in vitro investigation was to evaluate the dimensional stability of dental digital models made by impression scanning method. Twenty working models were produced. Twenty impressions were made from study models. The dimensional stability of models of two groups (stone and digital models) was examined using six landmark distances. Stone models were measured through digital vernier calipers. Digital models were measured by the computer program. Statistical analyses were performed with Wilcoxon rank sum test (${\alpha}=0.05$). The mean of six landmark distances were significantly larger in the stone models than in the digital models (p<0.05) but digital models showed clinically acceptable accuracy.