• The Journal of Korean Academy of Prosthodontics
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• v.42 no.2
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• pp.133-141
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• 2004

Statement of problem : Porcelain restorations are widely used in restorative dentistry with a high degree of general success. However, porcelain is brittle and may fracture intraorally. Sometimes a repair may be attempted using composite resin and bonding system available. Color stability of porcelain repair resins affects esthetics and prognosis of prosthesis, so that provides important criteria for the choice of porcelain repair resins. Purpose : The purpose of this study was to investigate the color stability of composite resins used widely as porcelain repair system. Materials and method : Composite resins used for this study were Carisma(Kulzer, Germany), Tetric ceram(Ivoclar, Liechtenstein), Filtek Z250(3M, USA), and Arabesk Top(VOCO, Germany). Thirty disc-shaped specimens($10{\times}2mm$) were fabricated from each composite resin. Color changes of specimens after treatment using thermocycling system(KD-TCS30, Kwang-duk F.A. Korea) and after immersion in methylene blue(0.05% by Wt) were measured with colorimeter(Model Tc-6Fx, Tokyo Denshoku Co.) and obtained data were analyzed. Results and Conclusion: The results obtained from this study were as fo11ows. 1. The color change of Filtek Z250 was lesser than those of Tetric ceram and Arabesk Top after thermocycling (12000 times). 2. All of the composite resins in this study showed increase of color change according to increase of thermocycling frequency. 3. After treatment with methylene blue, the color change of Arabesk Top was greater than those of Carisma and Tetric ceram, and Tetric ceram was more stable than others.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.171-179
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• 1991

The purpose of this study was to investigate the color stability of 3 porcelain repair composite resins Twenty specimens of each composite resin were made and ten specimens were polished at 10 minutes after polymerization, and the others were polished at 48 hours after polymerization. For 60 days, the color characteristics were measured by fiber-optic colorimeter (Model Tc-6FX, Tokyo Denshoku Co.). The obtained results were as follows: 1. The changes of $a^*$ value and $b^*$ value in composite resin polished at 10min. after polymerization were greater than those of composite resins polished at 48 hrs. after polymerization. 2. The $a^*$ values of all composite resins were increased and the $b^*$ values were decreased. 3. The $L^*$ values were decreased in composite resin manufactured by K & B Co., which were polished at 10min. after polymerization, but increased in composite resin manufactured by K & M Co., polished at 48 hrs. after polymerization.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.195-209
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• 1991

When the porcelain fused to metal restorations were fractured at the metal interface, various techniques and materials for intraoral porcelain repair have been suggested. The purpose of this study was to investigate the effect of metal surface treatment method and water storage on the shear bond strength of four porcelain repair systems. : Clearfil(Kuraray), All-bond(Bisco), Superbond C & B(Sun Medical), Panavia OP(Kuraray). After the metal surfaces of the specimens were sandblasted by aluminum oxide or roughened by diamond point, they were stored in double deionized water(24 Hr., $37^{\circ}C$) and thermocycling was performed(24 Hr., 1024 cycles), and again half of specimes were stored in water bath(2 Months, $37^{\circ}C$). Mean shear bond strength and mode of failure were recorded. The results of this study were obtained as follows : 1. Differences were observed between the sandblasted and diamond - treated specimens in Clearfil, All-bond, and Superbond. No statistically significant differences were observed in Panavia. 2. The 2-month storage time significantly affected the bond strength of All-bond and Superbond. No statistically significant differences were observed in Clearfil and Panavia. 3. The failures were observed at the interface between opaque resin and the metal in Clearfil and All-bond. 4. The failures were observed at the interface between opaque resin and veneered resin in Panavia. The failures were observed at the interface between opaque resin and veneered resin in Superbond, but 40% of them were fractured at the interface between the metal and opaque resin after 2-month storage time.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.593-593
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• 2001

Esthetic restoration techniques can be categorized into "Direct techniques" consist only of intraoral procedures and "Indirect techniques" include intraoral as well as extraoral laboratory steps. Those made extraorally exhibit generally enhanced esthetic potential and anatomy and better hardness and wear resistance, indirect esthetic restorations numerously applied in contemporary dentistry. Indirect restorative materials can be divided into two categories; composite resin-based materials and ceramic-based materials. These materials shows various were resistance, modulus of elasticity, repair postenital, chemical stability, and different laboratory procedures. In this session, benefit of indirect techinques, case selection of this kind of restorations, and material characteristics and fabrication produre of those materials will ber reviewed; Targis, Sculpture, Belleglass, and Post-curing of restorative composite resins in resin-based materials; Dicor, Empress, Cerec, Celay, and conventional firing porcelain in ceramic based materials.