Techniques previously utilized for chemical analysis of enamel surfaces are generally unsuitable for in-vivo testing. This study explored the utility of internal reflection spectroscopy (IRS) as a non-destructive method for enamel-surface analysis. Powders (enamel plus reference inorganic materials) and solids (flattened and unaltered enamel slabs) were analysed by IRS. Most samples were mounte...

Nanoshells are useful in near-infrared (NIR) applications because of the red shift of the Mie resonance into NIR. Silica/gold/silver nanoshells were prepared via gold anchoring and characterized by Mie-theoretical calculations and transmission electron microscopy, which indicated a broad and enhanced NIR absorption and a partially coated, mottled Ag/Au structure on the silica core. The mottled ...

Translucency of human dental enamel was determined by total transmittance of wavelengths from 400 to 700 nm. The transmission coefficient at 525 nm was 0.481 mm-1. Total transmission of light through human dental enamel increased with increasing wavelength. Human tooth enamel is more translucent at higher wavelengths. The translucency of wet human enamel and enamel after dehydration was also me...

The extracellular tooth enamel matrix is a unique, protein-rich environment that provides the structural basis for the growth of long and parallel oriented enamel crystals. Here we have conducted a series of in vivo and in vitro studies to characterize the changes in matrix shape and organization that take place during the transition from ameloblast intravesicular matrices to extracellular subu...

Teeth from Megalobatrachus japonicus were prepared for scanning electron microscopy (SEM) and electron microprobe analyzer (EMPA) to assay the elements of the enamel layer. The enamel layer of each of tooth is thin and the arrangement of the enamel crystals is regular in the Megalobatrachus japonicus. Based on calcium, phosphate and magnesium levels of distribution, the calcification level of t...

The aim of this study was to determine whether there was any difference in the degree of enamel loss at bond-up, debond and enamel clean-up when two different adhesive systems were tested and with four different methods of enamel clean-up. The adhesive systems were 37 per cent o-phosphoric acid with Transbond XT (group 1) and 10 per cent poly(acrylic acid) conditioner with Fuji Ortho LC (group ...

Afropithecus turkanensis, a 17-17.5 million year old large-bodied hominoid from Kenya, has previously been reported to be the oldest known thick-enamelled Miocene ape. Most investigations of enamel thickness in Miocene apes have been limited to opportunistic or destructive studies of small samples. Recently, more comprehensive studies of enamel thickness and microstructure in Proconsul, Lufengp...

During eating, the teeth usually endure the sharply temperature changes because of different foods. It is of importance to investigate the heat transfer and heat dissipation behavior of the dentino-enamel junction (DEJ) of human tooth since dentine and enamel have different thermophysical properties. The spatial and temporal temperature distributions on the enamel, dentine, and pulpal chamber o...

Dental enamel thickness continues to feature prominently in anthropological studies of ape and human evolution, as well as studies of preventative oral care and treatment. Traditional studies of enamel thickness require physical sectioning of teeth for linear and scaled measurements. Recent applications of microtomographic imaging allow scientists to employ larger and more diverse samples, incl...

D uring mammalian tooth formation, two proteinases are secreted by ameloblasts: enamelysin (MMP-20) and kallikrein-4 (KLK4). Enamelysin is the early protease. It is expressed by ameloblasts throughout the secretory stage and part of the maturation stage. KLK4 is the late protease; its expression by ameloblasts begins in the transition stage and continues throughout enamel maturation. 5 Expressi...