Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using ligh...

Our objectives in this study were to perform separate proteomic analyses of porcine soft and hard enamel matrices, using the ProteomeLab PF-2D System, to compare the contents of the hard and soft enamel and to identify matrix constituents that are absent from the early maturation stage. Developing first permanent molars were dissected from 6-month-old pigs. Both immature and mature enamel sampl...

Enamel thickness is highly susceptible to natural selection because thick enamel may prevent tooth failure. Consequently, it has been suggested that primates consuming stress-limited food on a regular basis would have thick-enameled molars in comparison to primates consuming soft food. Furthermore, the spatial distribution of enamel over a single tooth crown is not homogeneous, and thick enamel...

Human dentin is known to be susceptible to failure under cyclic loading. Surprisingly, there are few reports that quantify the effect of such loading, considering the fact that a typical tooth experiences a million or so loading cycles annually. In the present study, a systematic investigation is described of the effects of prolonged cyclic loading on human dentin in a simulated physiological e...

J. O. Turner was the first who described the developmental defect of permanent tooth caused by periapical inflammation of temporary predecessor. This disorder is most common in the upper front teeth and premolars. These disorders are collectively called developmental defects of enamel (DDE). They are visible deviations from the normal translucent enamel resulting from enamel organ dysfunction. ...

Dental enamel is the only mineralized tissue of epithelial origin in mammals. The exceptional structural complexity and physical properties of tooth enamel seem to be dependent upon the properties of the protein matrix precursor. Proteins involved in enamel biosynthesis guide hydroxyapatite mineral formation, making the tooth enamel the hardest tissue in the vertebrate body. In dentistry, due t...

A three-dimensional reconstruction of the rod profiles seen in inner and outer rat incisor enamel was made from serial 1 μ cross sections of a decalcified upper incisor. The enamel rod was found to be an elongated structure which travelled incisally relative to its origin and ran continuously from the dentino-enamel junction to the enamel surface. The rod was divisible into an inner and outer e...

An infinite elastic medium with a planar crack is considered. The crack is subjected to the pressure of fluid injected at a point on the crack surface. Description of the crack growth is based on the lubrication equation (balance of the injected fluid and the crack volume), the equation for crack opening caused by fluid pressure on the crack surface, the Poiseuille equation related local fluid ...

Amelogenin, enamelin, sheathlin (ameloblastin/ amelin), enamelysin (MMP-20), and KLK4 (EMSP-1) are the major structural proteins and proteinases in developing tooth enamel. Recently, odontoblasts were reported to express amelogenin, the most abundant enamel protein. In this study, we hypothesized that odontoblasts express all enamel proteins and proteases, and we measured their relative mRNA le...

Dental enamel is prone to damage by chipping with large hard objects at forces that depend on chip size and enamel toughness. Experiments on modern human teeth have suggested that some ante-mortem chips on fossil hominin enamel were produced by bite forces near physiological maxima. Here, we show that equivalent chips in sea otter enamel require even higher forces than human enamel. Increased f...