• Journal of Yeungnam Medical Science
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• 제41권2호
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• pp.80-85
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• 2024

Background: This study aimed to compare and evaluate the marginal fit of nanocomposite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays. Three types of nanocomposite CAD/CAM blocks (HASEM, VITA Enamic, and Lava Ultimate) were used as materials. Methods: Class II disto-occlusal inlay restorations were prepared on a typodont mandibular right first molar using diamond rotary instruments. The inlays were fabricated using CAD/CAM technology and evaluated using the silicone replica technique to measure marginal gaps at five locations on each inlay. The data were analyzed by two-way analysis of variance and Tukey post hoc tests (α=0.05). Results: There were no significant differences in the marginal gaps based on the type of nanocomposite CAD/CAM inlay used (p=0.209). However, there was a significant difference in the marginal gaps between the measurement regions. The gingival region consistently exhibited a larger marginal gap than the axial and occlusal regions (p<0.001). Conclusion: Within the limitations of this in vitro study, the measurement location significantly influenced the marginal fit of class II disto-occlusal inlay restorations. However, there were no significant differences in the marginal gaps among the different types of CAD/CAM blocks. Furthermore, the overall mean marginal fits of the class II disto-occlusal inlay restorations made with the three types of nanocomposite CAD/CAM blocks were within the clinically acceptable range.

• 대한정형외과스포츠의학회:학술대회논문집
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• 대한정형외과스포츠의학회 2004년도 The 7th korea-japan joint meeting of orthopaedic sports medicine
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• pp.24-24
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• 2004

• 대한정형외과스포츠의학회:학술대회논문집
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• 대한정형외과스포츠의학회 2004년도 The 7th korea-japan joint meeting of orthopaedic sports medicine
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• pp.25-25
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• 2004

• 대한관절경학회지
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• 제2권2호
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• pp.135-140
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• 1998

From 1989 to 1994, authors have reconstructed the posterior cruciate ligament(PCL) in 51 knees with an autogenous central one-third of the patellar tendon by transtibial two tunnel technique, but there were not a few cases of unfavorable results. So from January 1995, we have reconstructed the PCL deficient knees by "modified tibial inlay technique" to avoid the grafted tendon abrasion at the posterior opening of the tibial tunnel(killer turn). Purpose of this study was to compare the results of two surgical techniques and what its advantages and disadvantages are. We could follow up 39 cases of transtibial two tunnel techique group(group A) more than one year, average being 23.7 months and 21 cases of modified tibial inlay technique group(group B) more than 12 months, average being 14.7 months. The clinical results were evaluated by the OAK knee scoring system ($M{\ddot{u}}ller$'s criteria) and the posteror stress roentgenography (push view) with Telos stress device compared with the uninjured knees. The arthroscopic second-look findings were also evaluated. In group A : The $M{\ddot{u}}ller$'s knee score was average 80.1 points, the posteror displacement in push view was average 4.4mm at the last follow up. There were 17 cases(44%) of unfavorable results which showed unstable posterior displacement more than 4mm compared with the uninjured knee in push view. Among the 19 cases of arthroscopic second look examinations, nearly normal PCL appearances of the grafted tendons were noted only in 9 cases(47%). In group B : The $M{\ddot{u}}ller$'s knee score was average 86.7 points, the posterior displacemnet in push view was average 3.6mm at the last follow up. There were 5 cases(23.8%) of unfavorable results which showed unstable posterior displacement more than 4mm compared with the uninjured knee in push view but 4 out of 5 cases showed 6mm posterior displacement in push views. Among the 7 cases of arthroscopic second-look examinations, 6 cases(86%) showed nearly normal PCL appearances of the grafted tendons. In modified tibial inlay technique of PCL reconstruction, it was easier to pull out the BPTB and in cases of remained laxed meniscofemoral ligament it was easier to preserve the remained structures than transtibial two tunnel technique. We expect the "modified tibial inlay technique" may solve the problem of grafted patellar tendon abrasion at the posterior orifice of tibial tunnel and may contribute to the successful PCL reconstruction.

• 디지털융복합연구
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• 제12권11호
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• pp.505-513
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• 2014

현대 금속공예는 대량생산을 목표로 예술성이 결여된 단순한 표현 방법과 한정적 기술만을 사용하여 우리의 전통과 개성이 상실되어가고 있다. 앞으로 현대 금속공예의 발전과 우리 고유의 문화를 계승하기 위해서는 고대부터 전해온 전통공예기법을 고찰해야 할 필요성을 갖는다. 입사공예는 고도의 집중력과 기술력을 필요로 하며 당대 문화와 사상을 잘 보여주는 대표적인 전통금속공예기법이다. 입사기법이 국내에 처음으로 나타난 시대는 삼국시대로 백제, 가야, 신라에서 찾아볼 수 있다. 나아가 입사공예를 현대금속공예에 활용하였을 때 우리 고유의 예술적인 표현과 역사적 가치를 부여할 수 있는 가능성을 발견할 수 있었다. 이를 위해 전통의 기법을 명확하게 익힐 수 있는 교육의 기회를 넓히고 현대공예에 알맞게 수용할 수 있는 실용적 방안을 지속적으로 모색해야 비로소 현대 금속공예의 발전과 우리 고유의 개성을 확고히 자리매김하기 할 수 있을 것으로 전망한다.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.121-132
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• 1991

The purpose of the study was to evaluate the marginal sealing effect of composite resin inlays according to the luting techniques and compare them to the conventional direct resin filling technique. 90 cavities of class V were prepared on the buccal surface of 90 extracted molar teeth, which were divided into four groups. Cavities of control group were directly filled with Scotchbond 2 and P - 50, and those of composite resin inlay groups were luted with one of the followings: Adhesive bond followed by Adhesive cement, All bond followed by Adhesive cement, Fuji - ionomer type L All the specimens were immersed in India ink dye solution for 7 days at $37^{\circ}C$ incubator after thermocycling between $5^{\circ}C$ and $60^{\circ}C$ and longitudinally sectioned with diamond disk inot two parts All the specimens were observed at the occlusal and gingival margins and statistical analysis was performed. The results were as follows: 1. Groups filled with composite resin inlay showed less marginal leakage than the group directly filled(p<0.01). 2. There was no significant difference in marginal leakage between composite resin inlay groups luted with Adhesive bond followed by Adhesive cement and the group luted with All bond followed by Adhesive cement(p>0.05). 3. At occlusal margins, Composite resin inlay group luted with Adhesive bond followed by Adhesive cement showed less marginal leakage than the group luted with Fuii ionomer type I(p<0.01). At gingival margins, composite resin inlay group luted with All bond followed by Adhesive cement showed less marignal leakage than the group luted with Fuji ionomer type I(P<0.01).

• Restorative Dentistry and Endodontics
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• 제25권3호
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• pp.321-337
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• 2000

Dental caries, one of the most frequent dental disease, become larger because it can be thought as a simple disease. Further more, it can progress to unexpected root canal therapy with fabrication of crown that needs reduction of tooth structure. Base is required in a large caries and ZOE, ZPC, glass ionomer are used frequently as base material. They, with restorative material, can affect the longevity of the restoration. In this study, we assume that the mandibular 1st molar has deep class I cavity. So, installing the 3 base material, 3 kinds of fillings were restored over the base as follows; 1) amalgam only, 2) amalgam with ZPC, 3) amalgam with ZOE, 4) amalgam with GI cement, 5) gold inlay with ZPC, 6) gold inlay with GI cement, 7) composite resin only, 8) composite resin with GI cement. After develop the 3-dimensional model for finite element analysis, we observe the distribution of stress and temperature with force of 500N to apical direction at 3 point on occlusal surface and temperature of 55 degree, 15 degree on entire surface. The analyzed results were as follow : 1. Principal stress produced at the interface of base, dentin, cavity wall was smallest in case of using GI cement as base material under the amalgam. 2. Principal stress produced at the interface of base, dentin, cavity wall was smaller in case of using GI cement as a base material than ZPC under gold inlay. 3. Composite resin-filled tooth showed stress distributed over entire tooth structure. In other words, there was little concentration of stress. 4. ZOE was the most effective base material against hot stimuli under the amalgam and GI cement was the next. In case of gold inlay, GI cement was more effective than ZPC. 5. Composite resin has the small coefficient of thermal conductivity. So, composite resin filling is the most effective insulating material.

• 대한치과보철학회지
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• 제41권6호
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• pp.762-771
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• 2003

Statement of problem. In dentistry, the minimally prepared inlay resin-bonded fixed partial denture (FPD) made of new ceromer / fiber-reinforced composite (FRC) was recently introduced. However, the appropriate dimensions for the long-term success and subsequent failure strength are still unknown. Purpose. The aim of this study was to investigate the most fracture-resistible thickness combination of the ceromer / FRC using a universal testing machine and an AE analyzer. Material and Methods. A metal jig considering the dimensions of premolars and molars was milled and 56-epoxy resin dies, which had a similar elastic modulus to that of dentin, were duplicated. According to manufacturer's instructions, the FRC beams with various thicknesses (2 to 4 mm) were constructed and veneered with the 1 or 2 mm-thick ceromers. The fabricated FPDs were luted with resin cement on the resin dies and stored at room temperature for 72 hours. AE (acoustic emission) sensors were attached to both ends, the specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. The AE and failure loads were recorded and analyzed statistically. Results. The results showed that the failure strength of the ceromer/FRC inlay FPDs was affected by the total thickness of the connectors rather than the ceromer to FRC ratio or the depth of the pulpal wall. Fracture was initiated from the interface and propagated into the ceromer layer regardless of the change in the ceromer / FRC ratio. Conclusion. Within the limitations of this study, the failure loads showed significant differences only in the case of different connector thicknesses, and no significant differences were found between the same connector thickness groups. The application of AE analysis method in a fiber-reinforced inlay FPD can be used to evaluate the fracture behavior and to analyze the precise fracture point.

• 대한치과기공학회지
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• 제42권1호
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• pp.9-16
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• 2020

Purpose: The purpose of this study was to compare the marginal and internal fit of lithium disilicate ceramic inlay produced by heat pressing that inlay pattern made by subtractive manufacturing and additive manufacturing method. Methods: A mandibular lower first molar that mesial occlusal cavity (MO cavity) die was prepared. After fabricating an epoxy resin model using a silicone impression material, epoxy resin die was scanned with a dental model scanner to design an MO cavity inlay. The designed STL pile was used to fabricate wax patterns and resin patterns, and then lithium disilicate ceramic inlays were fabricated using hot-press method. For the measurement of the marginal and internal gap of the lithium disilicate, silicone replica method was applied, and gap was measured through an optical microscope (x 80). Data were tested for significant differences using the Mann-Whitney Utest. Results: The marginal fit was 103.56±9.92㎛ in the MIL-IN group and 81.57±9.33㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). The internal fit was 120.99±17.52㎛ in the MIL-IN group and 99.18±6.65㎛ in the SLA-IN group, with a significant difference found between the two groups (p<0.05). Conclusion: It is clinically more appropriate to apply the additive manufacturing than subtractive manufacturing method in producing lithium disilicate inlay using CAD/CAM system.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.55-72
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• 1993

The aim of this study was to compare the marginal leakage of class II light curing composite resin restoration according to filling methods. With using acid etching technique and dentin bonding agent, various methods were suggested to eliminate or reduce the marginal leakage. In this study, class II cavities were prepared in 100 extracted human premolars with cementum margin(1mm below the CEJ) and the teeth were randomly assigned to 5 groups of 20 teeth each. The teeth in group 1, 2, 3 and 4 were restored by direct filling methods using P-50 and Clearfil Photoposterior of 10 teeth each, but the method of insertion of the restorative materials varied with each group. And the teeth in group 5 were restored by inlay method using Kulzer Inlay and CR Inlay. Filling methods are as follows : Group 1 : The composite resin was inserted in one layer in the proximal box and one layer in the occlusal portion. Group 2 : Insertion was in two equally thick horizontal layers in the proximal box. Group 3 : Insertion was in two diagonally placed layers in the proximal box. Group 4 : The composite resin was inserted in the same way as in group 3 except that a glass ionomer liner was first placed on the axial wall and gingival floor. Group 5 : The teeth were restored by Inlay technique using dure cure resin cement. All the teeth were thermocycled, stained with 1 % methylene blue solution, sectioned mesiodistally, and scored for marginal leakage. To compare the marginal leakage, ANOVA and T-test were used in analysis. The following results were obtained : 1. In direct filling methods, there was no significant difference in marginal leakage at both occlusal and cervical margins. 2. In all groups, occlusal margin showed significantly less leakage than cervical margin. 3. In group using glass ionomer liner, there was no significant reduction of marginal leakage at the cervical margin. 4. The group restored by inlay method showed significantly less marginal leakage than groups restored by direct filling methods at both occlusal and gingival margins. 5. There was no significant difference in each group according to filling materials.