Publications by authors named "H van der Lubbe"
The isolation of specific grain size classes of lithogenic samples and biogenic carbonate from the <63 µm fraction (i.e. clay and silt) of marine sediment is often a prerequisite to further pre-treatments and/or analytical measurements for palaeoceanographic studies.
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- The study aimed to identify the acceptable color difference thresholds in dental materials based on their chromaticity, utilizing two observer groups: dentists and laypersons.
- A panel of 40 participants evaluated 144 pairs of dental composites, categorized by low, medium, and high chroma, in controlled lighting to determine the acceptable thresholds using statistical methods.
- Results showed that acceptability thresholds varied significantly among chroma groups, indicating that observers preferred less colorful (low chroma) samples, which has implications for quality control in dental practices and research.
Usually, dentin and enamel shades are layered in dental restorations with the purpose of mimicking the natural appearance of teeth. The main objective of this study was to develop and assess accuracy of a color-prediction method for both monolithic and layered dental resin-based composites with varying shades and under different illuminants. A total of 15 different shades of VITAPAN Excell, VITAPAN Dentine and VITA Physiodens as well as VITA Enamel of five different thicknesses (0.
View Article and Find Full Text PDFObjective: The aim of this study was to assess the accuracy of a Principal Components Analysis (PCA)-based method for reflectance reconstruction and color estimation of layered dental resin-based composites with different thicknesses.
Method: Bi-layered samples of different clinically relevant thicknesses were created using shades of VITAPAN Excell (VE), VITAPAN Dentine (VD) and VITA Physiodens (VP), combined with their corresponding enamel shades. Spectral reflectance of all samples was measured over a black background using a non-contact spectroradiometer with CIE 45∕0 geometry.