Dentin constituents

Kramer, I. R. H. McLean, J. W. (1952). Alterations in the staining reactions of dentine resulting from a constituent of a new self-polymerizing resin. 

Ivory, or dentine, the main constituent of the teeth of mammals, is a relatively hard, cream-white material that can be carved or mechanically formed, and its surface can be polished to a high shine (O Connor et al. 1987 Wills 1968). Of particular interest is the ivory that makes up the tusks (large incisor teeth) of large mammals such as elephants, hippopotami, whales, narwhals, and... 

Clove oil is used due to the presence of eugenol as its main constituent. It acts by paralysing the sensory never endings. It is non-irritating but stains the dentine yellow. 

Although about 80—90 percent of the total citric acid in humans are localized in hard tissues as enamel, dentine, cementum and bones, very little is known on the biological function of citric acid in biocalcification. HA crystals are reported to be dissolved by the action of citric acid. The acid dissolves the crystals in such a way that the destruction is a preferential attack along the c-axis. It is highly probable that the HA crystallites present in mineralized tissues also do have a dislocation in the centre of the material 165). Another assumption describes that citric acid is a constituent of the aqueous phase of enamel or that citrate is bound to the surface of apatite by adsorption166). 

Elements are incorporated into teeth from the diet or by inhalation. The figure shows trace element profiles measured by laser ablation—plasma ionization-mass spectrometry of the dentine of teeth from a modem person and one who lived in Scandinavia about a.d. 1800. The contrast is striking. The old tooth contains significant amounts of tin and bismuth, which are nearly absent in the modern tooth. The old tooth contains more lead and antimony than the modem tooth. Tin and lead are constituents of pewter, which was used for cooking vessels and utensils. Bismuth and antimony also might come from pewter. 

Indeed, in the light of current mineralogical theory (McConnell, 1973a) pertaining to carbonate apatites, there is no need to search for either a precursor or any other solid phase in bone — either crystalline or noncrystalline. The chemical composition is indicated for the principal constituents of bovine (dry, fat-free) bone, compared with dental enamel and dentin (Table 3.1.7). When converted to oxides, these values for bone become ... 

Acid etching pretreatment of dentin prior to application of a resin restorative leaves the collagenous component of this substrate substantially untouched. The collagen at the dentin surface interferes with the mechanical adhesion of the hydroxyapatite, (the inorganic constituent of dentin) to the adhesive. Thus, in contrast to its successful use with enamel, etching pretreatment produces a bond between dentin and restorative resin that is too weak to withstand the forces encountered at the interface under clinical conditions. 

Table A3.1 Basic Constituents of Human Dentin and Enamel ...

The outer layer of a tooth is composed of calcified tissue, enamel, the hardest substance in the body. Enamel consists of 92%, by volume, hydroxyapatite laid down as a series of interlocking prisms aligned perpendicular to the tooth surface. The remaining constituents are 6% water and 2% organic material (mainly collagen). The bulk of the inside of the tooth consists of dentine, which is a vital tissue perforated throughout by tubules. These tubules are continuous from the pulp of the tooth to the outer surface and allow liquid flow. The approximate composition of dentine is 48% hydroxyapatite, 29% collagen and 23% water. 

Magne, D. et al. (2002) Eourier transform infrared microspectroscopic investigation of the organic and mineral constituents of peritubular dentin a horse study. Calcif. Tissue Int, 71 (2), 179-185. 

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