Tissues tooth sections

West NX, Maxwell A, Hughes JA, Parker DM, Newcombe RG, Addy M A method to measure clinical erosion the effect of orange juice consumption on erosion of enamel. J Dent 1998 26 329-335. Cowell CR An appliance for the study of tooth tissue in vivo. Brit Dent J 1974 137 61-62. Cowell CR, Allen RWB A comparison of dentine wear on prepared tooth sections in vivo using two toothpastes. Brit Dent J 1979 146 339-342. 

The chiton tooth, dentin and the sea urchin larval spicule reflect the enormous diversity of the field of biomineralization. They differ with respect to the nature of their mineral and macromolecular components, as well as their structures. Few underlying common strategies can be recognized the delineation of a dedicated space in which the mineralized tissue forms, the formation of mineral in a preformed framework within this space, and the precipitation of mineral from a supersaturated phase. In this section we will reexamine some of these underlying issues, focussing in particular on the microenvironment in which mineralization occurs. 

In Section 3.8 about dispersions, the use of permittivity or conductivity parameters was discussed. From Section 2.3.4, we know that conductivity is dependent on the density of charge carriers and their mobility. In the frequency range less than 10 MHz, tissue admittance is usually dominated by the conductivity of the body electroljrtes, but at higher frequencies it is dominated by the dielectric constant. The electroljrtes without cells, in particular urine and cerebrospinal fluid (CSF), have the highest low-frequency conductivity thus, the higher the cell concentration, the lower the low-frequency conductivity. Tooth, cartilage and bone, lipids, fat, membranes such as the skin stratum comeum (SC), and connective tissue may contain many inorganic materials with low conductivity, but they are very dependent on body liquid perfusion. Tissue conductivity data are tabulated in Table 4.2. 

The nervous system, the top layer of the epidermis, and tooth enamel are all formed from the ectoderm. This section will summarize the studies that have demonstrated the potential of hESCs to generate neural tissue when cultured on and inside biomaterial scaffolds, as there has been little focus to date on generating other regions of the ectoderm. 

---