• The Journal of the Korean dental association
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• v.50 no.7
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• pp.377-383
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• 2012

Recently, ceramic materials have become a popular choice for dentists performing esthetic indirect restorations. The longevity and success of ceramic dental restorations depends on the adhesive procedures of resin cements. However, dental ceramics can be classified in various ways, depending on the compositions. Also, the applications for resin cement require multiple clinical steps. Therefore, understanding the different ceramic substrates involved in each procedure, as well as the proper adhesive steps for the resin cements is important to us for long-term clinical success.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.296-302
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• 2014

Objectives: It is difficult to achieve adhesion between resin cement and zirconia ceramics using routine surface preparation methods. The aim of this study was to evaluate the effects of $CO_2$ and Er:YAG laser treatment on the bond strength of resin cement to zirconia ceramics. Materials and Methods: In this in-vitro study 45 zirconia disks (6 mm in diameter and 2 mm in thickness) were assigned to 3 groups (n = 15). In control group (CNT) no laser treatment was used. In groups COL and EYL, $CO_2$ and Er:YAG lasers were used for pretreatment of zirconia surface, respectively. Composite resin disks were cemented on zirconia disk using dual-curing resin cement. Shear bond strength tests were performed at a crosshead speed of 0.5 mm/min after 24 hr distilled water storage. Data were analyzed by one-way ANOVA and post hoc Tukey's HSD tests. Results: The means and standard deviations of shear bond strength values in the EYL, COL and CNT groups were $8.65{\pm}1.75$, $12.12{\pm}3.02$, and $5.97{\pm}1.14MPa$, respectively. Data showed that application of $CO_2$ and Er:YAG lasers resulted in a significant higher shear bond strength of resin cement to zirconia ceramics (p < 0.0001). The highest bond strength was recorded in the COL group (p < 0.0001). In the CNT group all the failures were adhesive. However, in the laser groups, 80% of the failures were of the adhesive type. Conclusions: Pretreatment of zirconia ceramic via $CO_2$ and Er:YAG laser improves the bond strength of resin cement to zirconia ceramic, with higher bond strength values in the $CO_2$ laser treated samples.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.271-280
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• 2013

Purpose: This study was to assess the effect of surface and heat treatment on the bond strength of veneering ceramics to zirconia. Methods: The specimens were divided into 7 groups according to surface treatment and heat treatment conditions prior to porcelain application. ten specimens from each group were subjected to a 3-point flexural test. In addition the influence of surface and heat treatment on surface roughness values and phase transformation of zirconia was evaluated. Statistical analysis was performed with one-way ANOVA and post hoc Tukey's test. Results: Bond strength ranged from $20.67{\pm}3.13MPa$ to $32.69{\pm}4.52$. Bond strength of surface treatment group was lower than that of control group but only $Al_2O_3$ sandblasting group was significant difference. Bond strength of heat treatment group was higher than that of surface treatment group but there was no statistical significance. Conclusion: Bond strength of veneering ceramics to zirconia was affected by surface and heat treatment.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_2
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• pp.309-314
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• 2022

The bonding strength [ISO22674] test was conducted by firing a dedicated ceramic powder on the surface of the dental titanium material treated with micro-arc oxidation. In the test group, an average result value of 34.34 MPa was obtained, and in the control group, a result value of 21.53 MPa was obtained. The bonding strength of the test group was higher than that of the control group by 12.81 MPa, resulting in a 37% improvement in durability of the dental artificial tooth ceramic restoration.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.1
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• pp.89-98
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• 2003

Titanium requires special ceramic system for veneering. Low fusing dental ceramics with coefficients of thermal expansion matching that of titanium have been developed. The purpose of this study was determine the bond strengths between cast and noncast pure titanium and two commercial titanium porcelains, and to compare the results with a conventional nickel-chromium alloy-ceramic system. The bond strengths were determined using a 3-point flexure test. Three-point flexure specimens $25{\times}3{\times}0.5mm$ were prepared After removal of ${\alpha}-case$ layer, they were veneered with $8{\times}3{\times}1mm$ of ceramics at the center of the bar. Specimens were tested in a universal testing machine. Within the limits of this study, the following conclusions were drawn: 1. The bond strengths between pure titanium and two commercial porcelains exceeded th lower limit of the bonding strength value in ISO 9693(25MPa). 2. There was no significant difference between cast and noncast titanium-porcelain bonds. 3. There was no significant difference between two commercial titanium porcelains. 4. The bond strengths of the titanium-porcelain systems ranged from 73% to 79% of that of the Ni-Cr-conventional porcelain system.

• Journal of Technologic Dentistry
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• v.28 no.2
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• pp.399-415
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• 2006

This research collected the curriculum for Dental Technology from a total of 20 schools-eighteen 3-year colleges and two 4-year colleges all in Korea. We divided 4 groups as regions from 20 colleges, and we compared the credit of university students who finished all the required courses and want to apply for a national examination and the credit to be had from another educational institution. As a result of this analysis, we get the conclusion below: 1. In the curriculum, average credit are shown like this order: Science of Dental materials 5.45 Orthodontics Technology 4.10 Dental Morphology 3.80 Oral Anatomy 3.05 Dental Health Science 2.45 Public Health Science 2.40 These show that the credit of fundamental studies, which is in order to take Dental Prosthetics, is increased. 2. In the curriculum, average credit are shown like this order: Crown and Bridge Technology 7.25 Removable Partial Dentures Technology 6.55 Complete Dentures Technology 6.40 Dental Ceramics 4.95 Inlay Technology 2.30 3. In the curriculum, average credit are shown like this order: Crown and Bridge Technology(Lab) 5.90 Removable Partial Dentures Technology(Lab) 5.35 Complete Dentures Technology(Lab) 5.30 Dental Ceramics(Lab) 4.35 Average points between regions in the subject of a national written exam are mostly similar, but the deviation among Science of Dental Materials, Crown and Bridge Technology, Removable Partial Dentures Technology, and Complete Dentures Technology is large. And in the practical technique exam, the deviation among Crown and Bridge Technology(Lab), Removable Partial Dentures Technology(Lab), and Complete Dentures Technology(Lab) is great.

• The Journal of the Korean dental association
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• v.58 no.7
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• pp.448-459
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• 2020

In addition to extensive research on polymer and metal three-dimensional (3D) printing, ceramic 3D printing has recently been highlighted in various fields. The biggest advantage of 3D printing has the ability to easily create any complex shape. This review introduces the 3D printing technology of ceramics according to the type of material and deals with the latest related research in the industrial field including the biomedical engineering field. Finally, the future of ceramic 3D printing technology available in dentistry will be discussed.

• Journal of the Korean Ceramic Society
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• v.37 no.3
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• pp.288-293
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• 2000

Effects of contact damage and residual stress for two kinds of dental restorative layered ceramics, porcelain/alumina and porcelain/zirconia bilayers, were observed with Hertzian and Vickers indentation methods. Indentation stress-strain behavior of each material, strength degradation of the coating material, and crack propagation behavior in the coating layer after Vickers indentation were examined by an optical microscope. As a result, porcelain as coating materials showed the classical brittleness. It was inferred that damage and strength in two bilayer system were dependent on thermal expansion mismatch between the coating material and the substrate, which affected the strength degradation. Residual stress resulting from thermal expansion mismtch was formed in the coating layer, and specially in the case of porcelain/zirconia, residual stress was eliminated as coating thickness decreased.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.312-316
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• 2015

PURPOSE. This study aimed to present the clinical applicability of restorations fabricated by a new method, by comparing the bond strength of between ceramic powder with different coefficient of thermal expansion and alloys fabricated by Selective laser sintering (SLS). MATERIALS AND METHODS. Fifty Co-Cr alloy specimens ($25.0{\times}3.0{\times}0.5mm$) were prepared by SLS and fired with the ceramic ($8.0{\times}3.0{\times}0.5mm$) (ISO 9693:1999). For comparison, ceramics with different coefficient of thermal expansion were used. The bond strength was measured by three-point bending testing and surfaces were observed with FE-SEM. Results were analyzed with a one-way ANOVA (${\alpha}$=.05). RESULTS. The mean values of Duceram Kiss ($61.18{\pm}6.86MPa$), Vita VM13 ($60.30{\pm}7.14MPa$), Ceramco 3 ($58.87{\pm}5.33MPa$), Noritake EX-3 ($55.86{\pm}7.53MPa$), and Vintage MP ($55.15{\pm}7.53MPa$) were found. No significant difference was observed between the bond strengths of the various metal-ceramics. The surfaces of the specimens possessed minute gaps between the additive manufactured layers. CONCLUSION. All the five powders have bond strengths higher than the required 25 MPa minimum (ISO 9693); therefore, various powders can be applied to metal structures fabricated by SLS.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.85-90
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• 2017

Mica-glass ceramics has features such as micro-sized crystals, high strength, chemical resistance, semitransparent optical properties, etc. Due to its superior material properties, mica glass ceramics have increasing applications in dental and medical components, insulation boards, chemical devices, etc. In many applications, especially for dental and medical components, ultra-precise polishing is required. However, it is known to be a very difficult-to-grind material because of its high hardness and brittle properties. Thus, in this study, a newly developed ultra-precise polishing method is applied to obtain nano-level surface roughness of the mica glass ceramics using magnetorheological (MR) fluids and nano abrasives. Nano-sized ceria particles were used for the polishing of the mica glass ceramics. A series of experiments were performed under various polishing conditions, and the results were analyzed. A very fine surface roughness of Ra=6.127 nm could be obtained.