• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.619-627
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• 1996

There are increasing use of composite resin in the posterior teeth and the new indirect inlay technique was introduced for compensating much troubles faced in direct technique. Many researchers insisted that overall properties of restorative materials were enhanced by an additional curing but this technique still has a problems about using cement material. Resin inlay obtains retention force from friction and another adhesion to tooth structure. A shape of cavity preparation was noted but studies about cement thickness and bond strength with cavity divergency are rare. The purpose of this study is to assess the effect of cavity divergency on cement thickness and bond strength of resin inlay. Cavities, which divergency was $6^{\circ}$, $16^{\circ}$, and $26^{\circ}$ in each group, were prepared and their divergency was verified by Adobe Photoshop program through the image capture with stereo microscope and FlexCam. Inlays were fixed into the cavities with a resin cement, Superbond and were handled under chemical (in 75% ethanol for 24 hrs.) and thermal stress (500 cycles from $5^{\circ}$ to $55^{\circ}C$). MXT 70 (x400) was used for measuring the cement thickness and bond strength was evaluated with a universal testing machine. Following results were obtained : 1. The cement thickness in Mean (S.D.) were; 35.58 (10.31)${\mu}m$ in $6^{\circ}$ group, 35.97 (10.49)${\mu}m$ in $16^{\circ}$ group, and 41.43 (9.33)${\mu}m$ in $26^{\circ}$ group. But there was no significant difference between groups. 2. The bond strength in Mean (S.D.) were ; 33.18 (5.53)kg in $6^{\circ}$ group, 23.47 (13.40)kg in $16^{\circ}$ group, and 19.75 (10.48)kg in $26^{\circ}$ group. $6^{\circ}$ group showed significantly higher value compared to $16^{\circ}$ and $26^{\circ}$ groups (p<0.05). Although the results of this study indicate $6^{\circ}$ divergency will be good for resin inlay, cavity preparation with this type will have lots of difficulties in manufacturing, try-in, and cementation procedures, such as deformation. So it is concluded that $16^{\circ}$ divergent cavity preparation is recommended in resin inlay technique.

• Journal of Technologic Dentistry
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• v.41 no.1
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• pp.21-27
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• 2019

Purpose: To evaluate 2D and 3D of occulsal, mesial-occlusal and mesial-occlusal-distal cavity of composite resin inlay. Methods: Abutment tooth 16, 36 of FDI system was selected for the study. Inlay prostheses classified as occlusal cavity (OC group), mesial-occlusal (MOC) and mesial-occlusal-distal cavity (MODC) were prepared using composite resin. Composite resin was injected with composite resin in prepared tooth cavity and then photopolymerized with UV light. Additional thermal polymerization was performed. Marginal gap of composite resin inlays were measured by digital microscope(x160) with silicone replica technique. The data was analyzed from statistical software for Kruskal-Wallis test (${\alpha}=0.05$). 3-dimensional analysis was analyzed through superimposition method. Results: The smallest 2D marginal fit measure of the three groups was $47.0{\pm}21.6{\mu}m$ in the MOC group. The largest 2D marginal was $69.1{\pm}33.8{\mu}m$ in the MODC group. In the trueness of the three groups, the most accurate figure was $14.4{\pm}2.3{\mu}m$ for the MODC group. In Precision, the most accurate figure was $14.5{\pm}4.3{\mu}m$ for the MODC group. Conclusion : In this study, 2D marginal fit of OC, MOC, and MODC cavities fabricated with composite resin was applicable to all clinical applications. In the 3D inner surface accuracy evaluation, the MODC group showed the accuracy results.

• Korean Journal of Heritage: History & Science
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• v.55 no.2
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• pp.6-21
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• 2022

This paper examines the material culture of the Goryeo-Joseon Period through changes in the design and crafting of the earpick. In Chapter 2, terminology regarding earpicks is presented, and the culture of using earpicks is examined through fragmentary literature of the late Joseon Dynasty. Earpicks were first a personal hygiene tool, and, secondly, they played a symbolic role as a style accessory used by men, analogous to the fan carried by women of the time. In Chapter 3, earpick form are classified by period, and characteristic decorative techniques for each form are examined. During the Goryeo Dynasty, earpicks were sanitary tools, and, according to their form, they were classified into single and complex types. From Unified Silla to Goryeo, there is an angled type of connecting rod, and in the Goryeo period, there appeared earpicks with colorful decorations on the handle, completely forged earpicks with a thin and long shape, and earpicks which were part of multitools. Common decorative techniques include line expression, gold plating, cheophomun on the background, and inlay. Earpicks of the Joseon Dynasty are classified into sanitary tools or ornaments, according to their purpose of use. Sanitary tools are divided into single type and complex type, and earpicks used as ornaments include headdress, norigae, and sunchu. For earpick accessories, headdresses and norigae were used for women, and sunchu was used for men. The decorative techniques of earpicks during the Joseon Dynasty were mainly seen in the headdress earpicks. They were decorated with various colors in the Cloisonné method or bejeweled. Research on everyday tools among crafts is lacking; greater attempts to read the flow of time and approaches to material culture through everyday tools should be made.

• Korean Journal of Heritage: History & Science
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• v.56 no.4
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• pp.24-37
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• 2023

This study analyzes the materials and external characteristics of the Angbu-ilgu, a kind of scaphe sundial, which was newly designated as a Korean Treasure in 2022. The Angbu-ilgu Treasure is owned by three institutions - the National Palace Museum Of Korea, Gyeongju National Museum, and Sungshin Women's University Museum - and is similar as a twin in its material, size, outward appearance, as well as production techniques that include casting, silver inlays, and metal joints. The Three-Treasure Angbu-ilgu is made of brass in the ratio of 90.6: 6.0: 1.8 with Cu: Zn: Pb. This composition clearly differs from Treasure No. 845, an Angbuilgu which has a composition ratio of 82.2: 3.7: 11.8 with Cu: Zn: Pb. In this new Angbu-ilgu Treasure, the hemisphere's stand has four vertical pillars sculpted in a dragon pattern and bilateral wings carved in a cloud pattern on the pillars, which are joined to the hemisphere's horizontal ring with rivets and silver solders, respectively. The dragon-in-clouds pillar (雲龍柱) shows the most outstanding formative beauty of the various Angbu-ilgu pillars produced in the late Joseon Dynasty. It can be seen that the altitude of the north pole engraved on the Angbu-ilgu was made after 1713. Production is, however, actually estimated to have occurred close to the 19th century, the era of the Jinju Kang family, who were professional Angbuilgu makers. Hopefully, this study will lead to a historical science and technology review with modern scientific instruments analyzing the materials and external characteristics of the three Angbu-ilgus designated as a Korean Treasure in 2022.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.71-92
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• 2023

This study investigates the symbolism and meaning of the bead design, its relationship with the Silla culture, and the conditions of glass bead manufacturing to verify the theory of Silla's production of Silla face-inlaid glass beads with excellent artistry and technology. The research method includes investigating the design analysis, ancient documents, myths, relics, glass, and metal production techniques. Moreover, Hongshan cultural relics and other cases of inlaid glass beads were collected. There are records in the literature that the people of Makhan, Buyeo and Silla of ancient Korea people considered beads as treasures and used them for accessories. It was confirmed that all the design elements of the bead-patterned hair topknot, golden crown, birds, and flower trees were closely related to the myth of Kim Al-ji of Silla, the oviparous tales and the sacred birds and divine beasts of the north. Moreover, the pattern and arrangements were found to be similar in other Silla relics. The origin of beads and face pendants was Hongsan culture, and a stone cast for beads was discovered in Bukpyo of Gojoseon, the lower-level culture of Hajiajeom. In addition, excavating inlaid glass beads from Sik-ri tombs of Korea and a face-inlaid glass bead from Toganmori tombs in Japan confirms the theory of Silla's production. The fact that the Baekje people of ancient Korea had a glass bead manufacturing office in Japan in the fifth centuries suggests that the Silla people also had a manufacturing plant in Java, Indonesia, because this place was a crossroads of Silla's Sea Silk Road and a source of raw materials and labors with a close relationship to Silla. Therefore, the face-inlaid glass bead was indeed self-made by Silla, who possessed the tradition of bead myths and hair topknot, and the high-level skills such as gold crowns and metal inlays.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.19-25
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• 2015

Nowadays, CAD/CAM is broadly used in dentistry for inlays, crowns, implant abutments and its spectrum is expanding to complete dentures. Utilizing CAD/CAM to fabricate complete dentures is expected to decrease chair time and the number of visits, thus decreasing total fabrication time, expenses and errors caused during fabrication processes. One of the systems using CAD/CAM, DENTCA$^{TM}$ CAD/CAM denture (DENTCA Inc. Los Angeles, USA) scans edentulous impressions, designs dentures digitally, fabricates try-in dentures by 3D printing and converts them into final dentures. Patients can wear final dentures after only 2 - 3 visits with satisfying adaptation. This case report introduces a 71-year-old male patient who visited to consult remaking of existing old dentures. Residual teeth with bad prognosis and root remnants were extracted and the patient used reformed existing mandibular denture for 2 months. And then DENTCA system started. One-step border molding was done using conventional tray of adequate size provided by DENTCA system and wash impression was taken. Gothic arch tracing was completed based on the vertical dimension of existing dentures. Both maxillary and mandibular trays were placed to the resultant centric relation and bite registration was taken. Then DENTCA scanned the bite registration, arranged the teeth, completed the festooning and fabricated the try-in dentures by 3D printing. The try-in dentures were positioned, occlusal plane and occlusal relations were evaluated. The try-in dentures were converted to final dentures. To create bilateral balanced occlusion, occlusal adjustment was done after clinical remounting using facebow transfer. The result was satisfactory and it was confirmed by patient and operator.

• Restorative Dentistry and Endodontics
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• v.36 no.5
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• pp.419-424
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• 2011

Objectives: This study was aimed to determine the effects of temporary sealing materials on microtensile bond strength between resin-coated dentin and resin inlay and to compare the bonding effectiveness of delayed dentin sealing and that of immediate dentin sealing. Materials and Methods: The teeth were divided into 4 groups: group 1, specimens were prepared using delayed dentin sealing after temporary sealing with zinc oxide eugenol (ZOE); group 2, specimens were prepared using immediate dentin sealing and ZOE sealing; group 3, specimens were prepared using immediate dentin sealing and Dycal (Dentsply) sealing; group 4, specimens were prepared using immediately sealed, and then temporarily sealed with a resin-based temporary sealing material. After removing the temporary sealing material, we applied resin adhesive and light-cured. Then the resin inlays were applied and bonded to the cavity with a resin-based cement. The microtensile bond strength of the sectioned specimens were measured with a micro-tensile tester (Bisco Inc.). Significance between the specimen groups were tested by means of one-way ANOVA and multiple Duncan's test. Results: Group 1 showed the lowest bond strength, and group 4 showed the highest bond strength (p < 0.01). When temporary sealing was performed with ZOE, immediate dentin sealing showed a higher bonding strength than delayed dentin sealing (p < 0.01). Conclusions: Based on these results, immediate dentin sealing is more recommended than delayed dentin sealing in bonding a resin inlay to dentin. Also, resin-based temporary sealing materials have shown the best result.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.87-94
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• 2009

The purpose of this study was to assess the current materials, methods and difficulties according to the year of licence and educational background of Korean dentists in Class II direct composite resin restorations. Total 17 questions were included in the questionnaire. Questions were broadly divided into two parts: first. operator's information. and second. the materials and methods used in Class II posterior composite restoration. The questionnaire was sent to dentists enrolled in Korean Dental Association via e-mail. Total 12,193 e-mails were distributed to dentists. 2,612 e-mails were opened, and 840 mails (32.2%) were received from respondents. The data was statically analyzed by chi-square test using SPSS(v. 12.0.1, SPSS Inc. Chicago, IL, USA). Male dentists among respondents was 79%. 60.3% of the respondents acquired their licences recently (1998-2007), and 77% practiced in private offices. 83.4% have acquired their knowledge through school lectures, conferences and seminars. For the Class II restorations, gold inlays were preferred by 65.7% of respondents, while direct composite resin restorations were used by 12.1 % amalgam users were only 4.4% of respondents. For the restorative technique, 74.4% of respondents didn't use rubber dam as needed. For the matrix. mylar strip (53.4%), metal matrix (33.8%) and Palodent system (6.5%) were used. 99.6% of respondents restored the Class II cavity by incremental layering. Obtaining of the tight interproximal contact was considered as the most difficult procedure (57.2%) followed by field isolation (21 %). Among various bonding systems, 22.6% of respondents preferred SE Bond and 20.2% used Single Bond. Z-250 was used most frequently among a variety of composite resins.