• Title/Summary/Keyword: Restorative design

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Review of clinical studies applying yttrium tetragonal zirconia polycrystal-based esthetic dental restoration (치과용 지르코니아로 제작된 심미보철물의 임상적 예후에 관한 문헌고찰)

  • Kim, Jae-Hong
    • Journal of Technologic Dentistry
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    • v.42 no.4
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    • pp.307-312
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    • 2020
  • Application of ceramic materials for fabrication of dental restoration materials has been a focus of interest in the field of esthetic dentistry. The ceramic materials of choice are glass ceramics, spinel, alumina, and zirconia. The development of yttrium tetragonal zirconia polycrystal (YTZP)-based systems is a recent addition to all-ceramic systems that have high strength and are used for crowns and fixed partial dentures. Computer-aided design/computer-aided manufacturing (CAD/CAM)-produced, YTZP-based systems are popular with respect to their esthetic appeal for use in stress-bearing regions. The highly esthetic nature of zirconia and its superior physical properties and biocompatibility have enabled the development of restorative systems that meet the demands of today's patients. Many in vitro trials have been performed on the use of zirconia; however, relatively fewer long-term clinical studies have been published on this subject. The use of zirconia frameworks for long-span fixed partial dentures is currently being evaluated; in the future, more in vivo research and long-term clinical studies are required to provide scientific evidence for drawing solid guidelines. Further clinical and in vitro studies are required to obtain data regarding the long-term clinical use of zirconia-based restorations.

The Influence of Guilt on Preference towards Imported Products: Focusing on Chinese Consumers (소비자의 죄책감이 수입품 선호에 미치는 영향에 관한 연구: 중국 소비자를 중심으로)

  • Chen, Xuan-Mei;Song, Ji-Young;Jeong, Hyewook
    • Asia-Pacific Journal of Business
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    • v.13 no.2
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    • pp.51-61
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    • 2022
  • Purpose - This paper investigates how consumers' feelings of guilt affect their preference for imported products. Choosing imported products over domestic products reveals that consumers' motivation is to improve themselves. This study also tries to examine whether choosing imported goods has a restorative effect on feelings of guilt. Design/methodology/approach - We ran two experiments to test our hypothesis. Participants were recruited in China and the data analysis software used in this study was SPSS 26.0 for analysis. Findings - The results show that consumers with guilt feelings are more likely to import products than to consume domestic products, the second result shows that choosing imported products has an effect on guilt. In addition, consumers with low self-efficacy in a guilty condition prefer imported products to domestic products. Research implications or Originality - Based on previous research that focused on how guilt activates consumers' self-improvement goals, this study shows that when consumers experience feelings of guilt, they prefer imported products to reduce their negative feelings. These findings are discussed in the light of their implications for research on consumer self-motivation and ways of coping with it.

Effect of local anesthesia on postoperative pain and hemostasis after dental rehabilitation under general anesthesia in pediatric patients: a randomized control trial

  • Amal R Batarseh
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.23 no.6
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    • pp.337-346
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    • 2023
  • Background: This study aimed to investigate the effect of local anesthesia (LA) on postoperative pain and hemostasis after dental rehabilitation under general anesthesia (DRGA) in pediatric patients. Methods: A total of 43 patients, aged 3-7 years and rated ASA I or II, who had a definitely negative rating on Frankel's behavior rating scale, were included in this two-arm, parallel-design, single-blinded, randomized, controlled study. The patients were allocated equally into two main groups receiving both restorative treatments and tooth extractions. Two pain scales and one bleeding scale were used. In Group A, the treatment was done with LA, and in Group B, the treatment was done without LA. Results: The statistical analysis revealed no significant differences in the pain scores between the groups. It also revealed significant differences in the bleeding scores between the groups but no significant differences in the duration of bleeding. Conclusion: Within the limitations of this study, the use of LA in pediatric dental patients undergoing DRGA had no effects on postoperative pain reduction or bleeding duration after teeth extraction. We also observed that the use of LA had an impact on the reduction in the bleeding scores in pediatric dental patients undergoing DRGA.

Sample size determination for conducting a pilot study to assess reliability of a questionnaire

  • Mohamad Adam Bujang;Evi Diana Omar;Diana Hui Ping Foo ;Yoon Khee Hon
    • Restorative Dentistry and Endodontics
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    • v.49 no.1
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    • pp.3.1-3.8
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    • 2024
  • This article is a narrative review that discusses the recommended sample size requirements to design a pilot study to assess the reliability of a questionnaire. A list of various sample size tables that are based on the kappa agreement test, intra-class correlation test and Cronbach's alpha test has been compiled together. For all calculations, type I error (alpha) was set at a maximum value of 0.05, and power was set at a minimum value of 80.0%. For the kappa agreement test, intra-class correlation test, and Cronbach's alpha test, the recommended minimum sample size requirement based on the ideal effect sizes shall be at least 15, 22, and 24 subjects respectively. By making allowances for a non-response rate of 20.0%, a minimum sample size of 30 respondents will be sufficient to assess the reliability of the questionnaire. The clear guideline of minimum sample size requirement for the pilot study to assess the reliability of a questionnaire is discussed and this will ease researchers in preparation for the pilot study. This study provides justification for a minimum requirement of a sample size of 30 respondents specifically to test the reliability of a questionnaire.

A comparison of the implant stability among various implant systems: clinical study

  • Kim, Jae-Min;Kim, Sun-Jong;Han, In-Ho;Shin, Sang-Wan;Ryu, Jae-Jun
    • The Journal of Advanced Prosthodontics
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    • v.1 no.1
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    • pp.31-36
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    • 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).

Influence of access cavity design on calcium hydroxide removal using different cleaning protocols: a confocal laser scanning microscopy study

  • Seda Falakaloglu;Merve Yeniceri Ozata;Betul Gunes;Emmanuel Joao Nogueira Leal Silva;Mustafa Gundogar;Burcu Gucyetmez Topal
    • Restorative Dentistry and Endodontics
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    • v.48 no.3
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    • pp.25.1-25.13
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    • 2023
  • Objectives: The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods: Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC. Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results: The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions: The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.

STRESS DISTRIBUTION FOR NITI FILES OF TRIANGULAR BASED AND RECTANGULAR BASED CROSS-SECTIONS USING 3-DIMENSIONAL FINITE ELEMENT ANALYSIS (만곡 근관에서 삼각 혹은 장방형 단면 구조의 니켈-티타늄 파일 응력 분포에 관한 3차원 유한요소 연구)

  • Kim, Hyun-Ju;Lee, Chan-Joo;Kim, Byung-Min;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
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    • v.34 no.1
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    • pp.1-7
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    • 2009
  • The purpose of this study was to compare the stress distributions of NiTi rotary instruments based on their cross-sectional geometries of triangular shape-based cross-sectional design, S-shaped cross-sectional design and modified rectangular shape-based one using 3D FE models. NiTi rotary files of S-shaped and modified rectangular design of cross-section such as Mtwo or NRT showed larger stress change while file rotation during simulated shaping. The stress of files with rectangular cross-section design such as Mtwo, NRT was distributed as an intermittent pattern along the long axis of file. On the other hand, the stress of files with triangular cross-section design was distributed continuously. When the residual stresses which could increase the risk of file fatigue fracture were analyzed after their withdrawal. the NRT and Mtwo model also presented higher residual stresses. From this result, it can be inferred that S-shaped and modified rectangular shape-based files were more susceptible to file fracture than the files having triangular shape-based one.

Shear bond strength of dental CAD-CAM hybrid restorative materials repaired with composite resin (치과용 복합레진으로 수리된 CAD-CAM hybrid 수복물의 전단결합강도)

  • Moon, Yun-Hee;Lee, Jonghyuk;Lee, Myung-Gu
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.3
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    • pp.193-202
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    • 2016
  • Purpose: This study was performed in order to assess the effect of the surface treatment methods and the use of bonding agent on the shear bond strength (SBS) between the aged CAD-CAM (computer aided design-computer aided manufacturing) hybrid materials and added composite resin. Materials and methods: LAVA Ultimate (LU) and VITA ENAMIC (VE) specimens were age treated by submerging in a $37^{\circ}C$ water bath filled with artificial saliva (Xerova solution) for 30 days. The surface was ground with #220 SiC paper then the specimens were divided into 9 groups according to the combination of the surface treatment (no treatment, grinding, air abrasion with aluminum oxide, HF acid) and bonding agents (no bonding, Adper Single Bond 2, Single Bond Universal). Each group had 10 specimens. Specimens were repaired (added) using composite resin (Filtek Z250), then all the specimens were stored for 7 days in room temperature distilled water. SBS was measured and the fractured surfaces were observed with a scanning electron microscope (SEM). One-way ANOVA and Scheffe test were used for statistical analysis (${\alpha}=.05$). Results: Mostly groups with bonding agent treatment showed higher SBS than groups without bonding agent. Among the groups without bonding agent the groups with aluminum oxide treatment showed higher SBS. However there was no significant difference between groups except two subgroups within LU group, which revealed a significant increase of SBS when Single Bond Universal was used on the ground LU specimen. Conclusion: The use of bonding agent when repairing an aged LAVA Ultimate restoration is recommended.

Case report - Rehabilitation of a patient's smile by applying a simple digital smile design method on a complex clinical situation. (Case report - 복잡해 보이는 전악 구강 재건 케이스에 간단한 digital smile design을 적용하여 환자의 미소를 회복시켜 주기)

  • Im, Hyung gu
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.29 no.2
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    • pp.103-117
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    • 2020
  • A beautiful smile has a great impact on the quality of life. It gives you confidence, and makes you function with a positive attitude, which will eventually bring the joy and happiness to daily lives. As dental practitioners, our mission is to bring back the bright smile of the people who come to see us. Restoring masticatory function is one thing but one should always remember that the esthetics should always come first in any kind of restorative procedures. When treating complex rehabilitation cases, treatment planning is probably the most important step before you start any dental procedures. Obviously, esthetics should be the ultimate goal of the treatment and one should approach a case step by step to achieve an optimal result. For the past few years, "digital smile design" has been introduced in the field of dentistry. It can be applied by using various methods and tools. In this article, a very basic form of 2-dimensional digital smile designing was utilized to treat a complete mouth rehabilitation case. We will discuss how the DSD concept can be applied to your daily practice with a simple photograph and photoshop.

The Abuse and Invention of Tradition from Maintenance Process of Historic Site No.135 Buyeo Gungnamji Pond (사적 제135호 부여 궁남지의 정비과정으로 살펴본 전통의 남용과 발명)

  • Jung, Woo-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.2
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    • pp.26-44
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    • 2017
  • Regarded as Korea's traditional pond, Gungnamj Pond was surmised to be "Gungnamji" due to its geological positioning in the south of Hwajisan (花枝山) and relics of the Gwanbuk-ri (官北里) suspected of being components to the historical records of Muwang (武王)'s pond of The Chronicles of the Three States [三國史記] and Sabi Palace, respectively, yet was subjected to a restoration following a designation to national historic site. This study is focused on the distortion of authenticity identified in the course of the "Gungnamji Pond" restoration and the invention of tradition, whose summarized conclusions are as follows. 1. Once called Maraebangjuk (마래방죽), or Macheonji (馬川池) Pond, Gungnamji Pond was existent in the form of a low-level swamp of vast area encompassing 30,000 pyeong during the Japanese colonial period. Hong, Sa-jun, who played a leading role in the restoration of "Gungnamji Pond," said that even during the 1940s, the remains of the island and stone facilities suspected of being the relics of Gungnamji Pond of the Baekje period were found, and that the traces of forming a royal palace and garden were discovered on top of them. Hong, Sa-jun also expressed an opinion of establishing a parallel between "Gungnamji Pond" and "Maraebangjuk" in connection with a 'tale of Seodong [薯童說話]' in the aftermath of the detached palace of Hwajisan, which ultimately operated as a theoretical ground for the restoration of Gungnamj Pond. Assessing through Hong, Sa-jun's sketch, the form and scale of Maraebangjuk were visible, of which the form was in close proximity to that photographed during the Japanese colonial period. 2. The minimized restoration of Gungnamji Pond faced deterrence for the land redevelopment project implemented in the 1960s, and the remainder of the land size is an attestment. The fundamental problem manifest in the restoration of Gungnamji Pond numerously attempted from 1964 through 1967 was the failure of basing the restorative work in the archaeological facts yet in the perspective of the latest generations, ultimately yielding a replication of Hyangwonji Pond of Gyeongbok Palace. More specifically, the methodologies employed in setting an island and a pavilion within a pond, or bridging an island with a land evidenced as to how Gungnamji Pond was modeled after Hyangwonji Pond of Gyeongbok Palace. Furthermore, Chihyanggyo (醉香橋) Bridge referenced in the designing of the bridge was hardly conceived as a form indigenous to the Joseon Dynasty, whose motivation and idea of the misguided restoration design at the time all the more devaluated Gungnamji Pond. Such an utterly pure replication of the design widely known as an ingredient for the traditional landscape was purposive towards the aesthetic symbolism and preference retained by Gyeongbok Palace, which was intended to entitle Gungnamji Pond to a physical status of the value in par with that of Gyeongbok Palace. 3. For its detachment to the authenticity as a historical site since its origin, Gungnamji Pond represented distortions of the landscape beauty and tradition even through the restorative process. The restorative process for such a historical monument, devoid of constructive use and certain of distortion, maintains extreme intimacy with the nationalistic cultural policy promoted by the Park, Jeong-hee regime through the 1960s and 1970s. In the context of the "manipulated discussions of tradition," the Park's cultural policy transformed the citizens' recollection into an idealized form of the past, further magnifying it at best. Consequently, many of the historical sites emerged as fancy and grand as they possibly could beyond their status quo across the nation, and "Gungnamji Pond" was a victim to this monopolistic government-led cultural policy incrementally sweeping away with new buildings and structures instituted regardless of their original space, and hence, their value.