Computable translucency as a function of thickness in a multi-layered zirconia
| Autor: | Jan-Frederik Güth, Florian Beuer, Josef Schweiger, Kurt Erdelt, Madalena Lucia Pinheiro Dias Engler, Anja Liebermann |
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| Rok vydání: | 2019 |
| Předmět: |
Ceramics
Materials science Surface Properties Logarithmic growth 030206 dentistry Esthetics Dental Curvature Dental Porcelain Dental Materials 03 medical and health sciences 0302 clinical medicine Dental porcelain visual_art Materials Testing Transmittance visual_art.visual_art_medium Curve fitting Cubic zirconia Zirconium Ceramic Oral Surgery Composite material Layer (electronics) |
| Zdroj: | The Journal of Prosthetic Dentistry. 121:683-689 |
| ISSN: | 0022-3913 |
| Popis: | Statement of problem Determining the relationship between variable thicknesses and the translucency of dental ceramics is essential for optimizing esthetics in different clinical situations. Purpose The purpose of this in vitro study was to analyze the relationship between layer thickness and translucency of 2 multi-layered monolithic zirconia materials and to develop an equation by which the grade of translucency can be calculated dependent on the materials' layer thicknesses in advance. Material and methods Two semisintered multi-layered zirconia blanks, namely KATANA Zirconia Super Translucent Multi-Layered Disk (Noritake Dental Supply Co, Ltd) and Zirconia Ultra Translucent Multi-Layered Disk (UTML) (Noritake Dental Supply Co, Ltd), were sectioned (N=96) to separate the 4 layers (n=12 per layer): enamel layer, transition layer 1, transition layer 2, body layer. All specimens were sintered in a furnace (M2 Plus; Thermo-Star) at 1500°C for 2 hours and automatically polished under water cooling up to P2400 for the thicknesses of 1.6, 1.3, 1.0, 0.7, and 0.4 mm. Transmittance of visible light was measured using a spectrophotometer (Lambda 35; Perkin Elmer). Data were analyzed using the Kolmogorov-Smirnov, 2-way ANOVA, and Scheffe post hoc tests (α=.01) and curve fitting. Results Analyzing the fitting of the values of the 8 material groups to the linear, exponential, and logarithmic curves, 7 of the 8 groups (not UTML body layer) fitted the most (R-square value closer to 1.0) to the logarithmic curve. Constants were obtained from the distance to the x-axis and the curvature. Conclusions The methodology of this study provided the materials' specific constants a and b by analyzing the translucency behavior of KATANA Super Translucent Multi-Layered Disk and Ultra Translucent Multi-Layered Disk in different thicknesses, allowing further translucency calculation by applying the developed formula and the constants. |
| Databáze: | OpenAIRE |
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