ABSTRACT
The most scientific and reliable method for deciding the tooth color is the instrumental measurement. However, such color measuring instrument shows the difference of the measuring value according to the diversified measuring condition. This study was conducted to evaluate what effect of the labial surface irregularity of the tooth to the result of the color measured by spectrometer. 11 models of the teeth were made by injecting the A2 shade Luxatemp Automix Plus (DMG, Germany) into the impression acquired from 11 adults. Standard disk samples (15 mm diameter, 7 mm thickness) were made with same material. CIE L*a*b* value was measured at the incisal, central, and gingival area of the central incisor, lateral incisor, canine and first premolar using Specbos 2100 (JETI, Germany) spectrometer. Color difference was calculated between labial surface and standard samples. Among all models of the teeth, L* and b* value showed the reducing tendency as they go toward the gingival area, but a* value showed the increasing tendency. Color difference between model teeth and standard samples showed the most difference at the incisal area, but the gingival area showed the least difference. And the canine showed the least color difference from the comparison of standard sample, and the central incisor showed the highest difference (p < 0.01). Although the visually detectable difference of the measuring value showed notably depending on the type and measured area (p < 0.05), L* and a* value showed notable differences depending more on the measured areas than on the type of the teeth.
Subject(s)
Adult , Humans , Bicuspid , Incisor , ToothABSTRACT
Laminin-1 is biologically active and can effect cellular proliferation, differentiation, migration, and apoptosis. In the central nervous system, neuronal cells are rarely reported to give positive reaction by laminin antibody staining. However, the original cell type which can produce the laminin molecule has not been well established. Since the neuronal cells of brain are derived from neuroectoderm, we thought that the neuronal cells should be able to produce the laminin molecules as other epithelial cells. In this study we aimed to explore whether the neuronal cells express the laminin chain mRNAs, and further to identify which types of laminin isoform are expressed at the specific sites of the brain structure. We found that neuronal cell was the important cell type in mouse brain, which could produce laminin isoforms. Although immunostainings disclosed reactivity of laminins in the basement membrane of capillaries as well as neuronal cells, mRNA expressions of laminins were intense only in the neuronal cells. It was relatively weak in the endothelial cells. Among neuronal cells the cortical cells of cerebrum, pyramidal cells of hippocampus, and Purkinje cells of cerebellum showed pronounced expression of laminin chain mRNA. Glial cells, especially astrocytes, were negative for laminin subtypes both in immunohistochemistry and in situ hybridization. Taken together, our data indicate that the neuronal cells of mouse brain actively produce laminin isoforms, and the resultant polymerized laminins are accumulated mainly in the basement membrane of capillaries. In conclusion, the results indicate that neuronal cells produce and utilize the different laminin chains to maintain the neurovascular environment of brain.