The effect of the variational combination of thickness of porcelain component on the color of ceramo-metal restorations

• Main Authors: Ching-Ting Chang, 張晶婷
• Other Authors: Kan-Sheng Shih
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/40455601115452219940

碩士 === 國防醫學院 === 牙醫科學研究所 === 97 === Abstract Ceramometal restorations not only restored original function but also esthetic, the color matching of ceramometal restorations is a big challenge in aesthetic dentistry. Computer color matching was utilized to analyze color information of nature teeth in clinic recently. We can't precisely reproduce the color even if we make the ceramometal restoration in accordance with the prescription offered by the instrument, that’s because there were no references about the thickness of porcelain layers from prescription, and also no standard procedure on fabricating ceramometal restorations. Therefore, the purpose of this study is to confer the effect of the variational thickness combination of porcelain component on color of ceramometal restorations. We observed the color distribution with changing contrast ratio of thickness of porcelain layers on the fixed amount space to build up porcelain layers. We chose the common used shade in clinic：A2, A3, and A3.5. And fabricated difference ratio thickness layers of opaque, dentin, and enamel porcelain specimen. 11 mm in diameter with a 0.3mm Ni-Cr alloy substructure, 2 thickness modes of opaque porcelain:0.1mm, 0.2mm, and 5 difference contrast ratio thickness of dentin/enamel porcelain : 0.25/1.25, 0.5/1.0, 0.75/0.75, 1.0/0.5, 1.25/0.25. 3shade, 2 thickness modes of opaque porcelain, 5 difference contrast ratio thickness of dentin/enamel porcelain, each group consisting 3 discs, totally 90 specimens. Control were shade guide and standard specimens without metal substructure and opaque porcelain. And then utilized spectrophotometer to measure the color distribution, and used student’s t test and linear regression analysis to proceed statistical analysis. The result showed that there were high correction between dentin porcelain thickness and CIELab 3 color coordinates (R2＞0.8410), CIELab 3 color coordinates L*, a*, b*, C*ab , value, and chroma of specimen were decreased with dentin porcelain layer increased. The result showed that there were high correction between the ratio of dentin/enamel porcelain layers and color (R2＞0.8768). As the ratio with dentin porcelain thickness increased, CIELab 3 color coordinates L*, a*, b*, hab , and C*ab increased. Specimen became lighter, more red and yellow. According to the result of this study, there were the references of the porcelain layers variations and color distribution which can offer dental technician an important criterion on fabricating restorations in clinic, and finish color matching restorations. In the future it must to investigate thoroughly, and solve the issue about the color matching in dental clinic. Key words：dentin porcelain, enamel porcelain, porcelain thickness, and color matching.