• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.132.2-132
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• 2003

• Journal of the Korean Ceramic Society
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• v.36 no.12
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• pp.1381-1389
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• 1999

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.125.2-125
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• 2002

• Journal of the Korean Academy of Esthetic Dentistry
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• v.32 no.2
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• pp.46-53
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• 2023

Porcelain fractures associated with metal ceramic(MC), all ceramic (AC), and zirconia restorations are common complications. Several factors of fracture are suggested; Property of materials, Design of the coping for metal ceramic, fabrication techniques, supporting structure, occlusal force, parafunctional habit are being considered. In this article, these factors are discussed in detail.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.24 no.2
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• pp.86-100
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• 2015

To harmonize with the remaining natural teeth a dentist and technician make an effort to do. Dental ceramic perfectly reproduce the functionality and esthetic is so moved that will deliver to the patient. However It is not easy to overcome the problem. Actually, it can't have the same spectrum curve between different object. The spectrum curve and reflectance is a unique feature of an object like fingerprints. So it is not that the identification of spectral curves that we usually focuses color. We need to understand the process of matamerism makes something like a combination of color perception. In other word that will tell in our field with ceramic teeth of the patient wish to match the color matching process to simulate the cone in our retinas with the same combination.

• The Journal of Advanced Prosthodontics
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• v.10 no.4
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• pp.259-264
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• 2018

PURPOSE. The purpose of this study was to evaluate the effect of the zirconia surface architecturing technique (ZSAT) on the bond strength between veneering porcelain and zirconia ceramic. MATERIALS AND METHODS. 20 sintered zirconia ceramic specimens were used to determine the optimal surface treatment time, and were randomly divided into 4 groups based on treatment times of 0, 1, 2, and 3 hours. After etching with a special solution, the surface was observed under scanning electron microscope, and then the porcelain was veneered for scratch testing. Sixty 3 mol% yttria-stabilized tetragonal zirconia polycrystal ceramic blocks were used for tensile strength testing; 30 of these blocks were surface treated and the rest were not. Statistical analysis was performed using ANOVA, the Tukey post-hoc test, and independent t-test, and the level of significance was set at ${\alpha}=.05$. RESULTS. The surface treatment of the zirconia using ZSAT increased the surface roughness, and tensile strength test results showed that the ZSAT group significantly increased the bond strength between zirconia and veneering porcelain compared to the untreated group (36 MPa vs. 30 MPa). Optimal etching time was determined to be 2 hours based on the scratch test results. CONCLUSION. ZSAT increases the surface roughness of zirconia, and this might contribute to the increased interfacial bond strength between zirconia and veneering porcelain.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.4
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• pp.215-222
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• 2023

3Y-TZP (3 mol% yttria-stabilized tetragonal zirconia polycrystals, 3Y-TZP) ceramics are emerging as dental implant materials due to their superior optical and mechanical properties as well as excellent biophysical properties, in spite of low bioactivity. In this study, we investigated to sintered properties and microstructural defects of dental zirconia implants fabricated by ceramic injection molding and post-HIP (Hot isostatic pressing) processing and analyzed the processing parameters related with the obtainment of its high sinterd density. Sintered and microstructural parameters, i.e, apparent density, grain size and phase composition of zirconia implants fabricated by injection molding were dependent on the fixtute size and implant type. Maximum sintered density of 99.2% and minimum grain size of 0.3-0.4 ㎛ were obtained from large-scaled 2-body sample. In 1-body ceramic implant, high sintered density of 99.5% was obtained, but it had a little monoclinic phase and wide grain size distribution.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.301-308
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• 2024

Ceramic materials are being explored as alternatives to toxic lead sheets for radiation shielding due to their favorable properties like durability, thermal stability, and aesthetic appeal. However, crafting effective ceramics for radiation shielding entails complex processes, raising production costs. To investigate local viability, this study evaluated Malaysian ceramic tiles for shielding in diagnostic X-ray rooms. Different ceramics in terms of density and thickness were selected from local manufacturers. Energy Dispersive X-ray Fluorescence (EDXRF) and X-ray Fluorescence (XRF) characterized ceramic compositions, while Monte Carlo Particle and Heavy Ion Transport code System (MC PHITS) simulations determined Linear Attenuation Coefficient (LAC), Half-value Layer (HVL), Mass Attenuation Coefficient (MAC), and Mean Free Path (MFP) within the 40-150 kV energy range. Comparative analysis between MC PHITS simulations and real setups was conducted. The C3-S9 ceramic sample, known for homogeneous full-color structure, showcased superior shielding attributes, attributed to its high density and iron content. Notably, energy levels considerably impacted radiation penetration. Overall, C3-S9 demonstrated strong shielding performance, underlining Malaysia's potential ceramic tile resources for X-ray room radiation shielding.

• The Journal of Advanced Prosthodontics
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• v.11 no.4
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• pp.215-222
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• 2019

PURPOSE. To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution. MATERIALS AND METHODS. 88 ceramic discs ($1.0mm{\times}10.0mm$) were manufactured - 44 nano-fluorapatite layering ceramics (IPS e.max Ceram. Group C) and 44 pressed lithium disilicate ceramic discs (IPS e. max Press - Group P). Each group was divided into 4 subgroups according to surface treatments: (G) Glaze, (S) Shofu polishing system (Shofu Inc.), (E) Edenta AG polishing System, (KG) $30-{\mu}m$ diamond granulation tip. Surface roughness (Ra) and color change (${\Delta}E$) measurings after the surface treatments were performed, before and 12 days after the immersion in coffee solution. A samples' qualitative analysis was conducted with a scanning electron microscopy (SEM). Data were statistically-treated with one-way-ANOVA and Duncan's tests, apart from paired t-test and Pearson's correlation test (${\alpha}=5%$). RESULTS. The decrescent order, both for surface roughness (Ra) and ${\Delta}E$ for both ceramics were: KG > E > S > G (P<.05). With exception for PG and CG subgroups, which did not present statistical difference between them, all other pressed ceramics subgroups presented smaller Ra values and greater ${\Delta}E$ values than the layering ceramics subgroups (P<.05). CONCLUSION. Although mechanical polishing systems presented intermediate Ra values, their colors were considered clinically acceptable. There is a strong correlation between the surface roughness and the color change of tested ceramics.

• Journal of Technologic Dentistry
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• v.32 no.4
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• pp.351-356
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• 2010

Purpose: The purpose of this study was to evaluate the fracture strength between the core and veneering ceramic according to 2 core materials, In-Ceram Alumina and In-Ceram Zirconia, fabricated by electro ceramic layering technique. 2 different fixed partial denture cores of three units were veneered by veneering ceramic(Ceranion, Noritake) (n=10). Methods: The fracture strengths between the core and veneering ceramic were measured through the 3 point bending test. The interfaces between the core and veneering ceramic were observed with the X-ray dot mapping of EPMA. Results: The result of fracture strength was observed that IZP group, In-Ceram Zirconia core, had higher fracture strength. IPA group, In-Ceram Alumina core, had fracture strength of 359.9(${\pm}$86.2) N. IZP group, In-Ceram Zirconia core, had fracture strength of 823.2(${\pm}$243.0) N. X-ray dot mapping observation showed that a major element in the core and veneering ceramic of IPA group was alumina and silica, respectively. No binder was observed in interfaces between the core and veneering ceramic, and no ion diffusion or transition was observed between the core and veneering ceramic. However, apparent ion diffusion or transition was observed between the core and veneering ceramic of IZP group.