10 research outputs found
Effect of heavy metals in recycled water used for household laundry on quality of cloth and washing machine
Development and assessment of an objective method of colour change measurement for acrylic denture base resins
Influence of surface roughness on the color of dental-resin composites*
This study deals with the influence of surface roughness on the color of resin composites. Ten resin composites (microfilled, hybrid, and microhybrid) were each polished with 500-grit, 1 200-grit, 2 000-grit, and 4 000-grit SiC papers. The roughness parameter (R
a) was measured using a Plμ confocal microscope, and field-emission scanning electron microscope (Fe-SEM) images were used to investigate filler morphology. Color was measured using a spectroradiometer and a D65 standard illuminant (geometry diffuse/0° specular component excluded (SCE) mode). Surface roughness decreased with grit number and was not influenced by filler size or size distribution. A significant influence of R
a on lightness (L
*) was found. Lightness increased with decreases in roughness, except for specimens that underwent polishing procedure 4 (PP4; 500-grit, 1 200-grit, 2 000-grit, and 4 000-grit SiC papers consecutively). Generally, it was found that surface roughness influenced the color of resin composites. The composites that underwent PP1 (500-grit SiC paper) exhibited significant differences in chroma (C
*), hue (h°), and lightness (L
*) compared to composites that underwent PP3 (500-grit, 1 200-grit, and 2 000-grit SiC papers consecutively) and PP4. Color difference (∆E*) between the polishing procedures was within acceptability thresholds in dentistry