Summary
The solubility properties of hydroxyapatite (HA) are compared with those of human dental enamel and dentin. The apatites used in this study were equilibrated with dilute phosphoric acid solutions in CO2-containing atmospheres. The experimental results are interpreted in terms of solubility models which consider the biological materials as either HA or carbonatoapatites. Both in the HA and the dental mineral systems, the results are consistent with the precipitation of another carbonate-containing apatitic phase during equilibration. However, although the chemical behavior of the HA systems is in very good agreement with predictions based on the solubility models, the results with the bioapatities are not; this inconsistency is more marked for dentin than for enamel but in both cases the results clearly indicate the inadequacy of assuming for these dental apatites the stoichiometry of HA. The models and the experimental results show that, in principle, it is possible to define the two dental minerals in terms of respective solubility product constants, if independent information is attained on the stoichiometry of these bioapatites.
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Biltz R, Pellegrino ED, Miller ST and Moffitt A (1970) Solubility behavior of the mineral substance of bone, tooth and shell. Clin Orthop 71:219–228
Moreno EC, Zahradnik RT (1974) Chemistry of enamel subsurface demineralization. J Dent Res 53:226–235
Patel PR, Brown WE (1975) Thermodynamic solubility product of human tooth enamel: powdered sample. J Dent Res 54:728–736
Margolis HC, Moreno EC (1985) Kinetic and thermodynamic aspects of enamel demineralization. Caries Res 19:22–35
Margolis HC, Murphy BJ, Moreno EC (1985) Development of caries-like lesions in partially saturated lactate buffers. Caries Res 19:36–45
Margolis HC, Moreno EC, Murphy BJ (1986) Effect of low levels of fluoride in solution on enamel demineralization in vitro. J Dent Res 65:23–29
Driessens FCM, van Dijk JWE, Borggreven JMPM (1978) Biological calcium phosphates and their role in the physiology of bone and dental tissues I. Composition and solubility of calcium phosphates. Calcif Tissue Res 26:127–137
Elliott JC (1964) The crystallographic structure of dental enamel and related apatites. Ph.D. Thesis, University of London
Holcomb DW, Young RA (1980) Thermal decomposition of human tooth enamel. Calcif Tissue Int 31:189–201
Elliott JC, Holcomb DW, Young RA (1985) Infrared determination of the degree of substitution of hydroxyl by carbonate ions in human dental enamel. Calcif Tissue Int 37:372–375
LeGeros RZ (1981) Apatites in biological systems. Prog Crystal Growth Charact 4:1–45
Aoba T, Moreno EC (1984) Preparation of hydroxyapatite crystals and their behavior as seeds for crystal growth. J Dent Res 63:874–880
Moreno EC, Margolis HC (1988) Composition of human plaque fluid. J Dent Res 67:1181–1189
Gee A, Deitz VR (1953) Determination of phosphate by differential spectrophotometry. Anal Chem 25:1320–1324
Kielland J (1937) Individual activity coefficients of ions in aqueous solutions. J Am Chem Soc 59:1675–1677
Avnimelech Y, Moreno EC, Brown WE (1973) Solubility and surface properties of finely divided hydroxyapatite. J Res Natl Bur Stds (A) Phys Chem 77A:149–155
Gregory TM, Moreno EC, Brown WE (1970) Solubility of CaHPO42H2O in the system Ca(OH)2−H3PO4−H2O at 5, 15, 25, and 37.5°C. J Res Natl Bur Stds (A) Phys Chem 78A:667–674
Harned HS, Owen BB (1957) Physical chemistry of electrolytic solutions, Reinhold, New York, pp 691–693, 755
Davidson CL, Arends J (1977) Thermal analysis studies on sound and artifically decalcified tooth enamel. Caries Res 11:313–320
Kuhl G, Nebergall WH (1963) Hydrogenphosphat- und carbonatapatite. Z Anorg Allg Chem 324:313–320
Kaufman HW, Kleinberg I (1979) Studies on the incongruent solubility of hydroxyapatite. Calcif Tissue Int 27:143–151
Moreno EC, Gregory TM, Brown WE (1968) Preparation and solubility of hydroxyapatite. J Res Natl Bur Stds (A) Phys Chem 72A:773–782
McDowell H, Gregory TM, and Brown WE (1977) Solubility of hydroxyapatite (Ca5(PO4)3OH) in the system calcium hydroxide-phosphoric acid-water at 5, 15, 25, and 37°C. J Res Natl Bur Stds (A) 81A:273–281
Doi Y, Eanes ED (1984) Transmission electron microscopic study of calcium phosphate formation in supersaturated solutions seeded with apatite. Calcif Tissue Int 36:39–47
Wagman DD, Evans WH, Parker VB, Schumm RH, Halow I, Bailey SM, Churney KL, Nuttall RL (1982) The NBS tables of chemical thermodynamic properties. Selected values for inorganic and C1 and C2 organic substances in Sl units. J Phys Chem Ref Data 11 [Suppl 2]
Gron P, Spinelli M, Trautz OR (1963) The effect of carbonate on the solubility of hydroxyapatite. Arch Oral Biol 8:251–263
LeGeros RZ, Tung MS (1983) Chemical stability of carbonate- and fluoride-containing apatites. Caries Res 17:419–429
LeGeros RZ, Trautz OR, LeGeros JP, Klein E, Shirra WP (1967) Apatite crystallites: effects of carbonate on morphology. Science 155:1409–1411
Theuns HM, Driessens FCM, van Dijk JWE, Groeneveld A (1986) Experimental evidence for a gradient in the solubility and in the rate of dissolution of human enamel. Caries Res 20:24–31
Driessens FCM, Heijligers HJM, Borggreven JMPM, Woltgens JHM (1984) Variations in the mineral composition of human enamel on the level of cross-striations and striae of Retzius. Caries Res 18:237–241
Mayer I, Vogel JC, Bres EF, Frank RM (1988) The release of carbonate during the dissolution of synthetic apatites and dental enamel. J Crystal Growth 87:129–136
Hiller CR, Robinson C, Weatherell JA (1975) Variations in the composition of developing rat incisor enamel. Calcif Tissue Res 18:1–12
Aoba T, Moreno EC (1990) Changes in the nature and composition of enamel mineral during porcine amelogenesis. Calcif Tissue Int (in press)
Aoba T, Moreno EC (1987) The enamel fluid in the early secretory stage of porcine amelogenesis. Chemical composition and saturation with respect to enamel mineral. Calcif Tissue Int 41:86–94
Aoba T, Moreno EC (1989) Mechanism of amelogenetic mineralization in minipig secretory enamel. In: Fearnhead RW (ed) Tooth enamel, V. Florence Publications, Yokohama, Japan, pp 163–167
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Moreno, E.C., Aoba, T. Comparative solubility study of human dental enamel, dentin, and hydroxyapatite. Calcif Tissue Int 49, 6–13 (1991). https://doi.org/10.1007/BF02555895
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DOI: https://doi.org/10.1007/BF02555895