A series of synthetic carbonated and non-carbonated apatites was investigated using high resolution transmission electron microscopy, and their dissolution behavior was tested under sink conditions, using the rotating disc method. n-Beam lattice images of the apatite samples were of a resolution greater than has been previously reported, and revealed an increase in crystalline disorder with the incorporation of carbonate in the apatite structure. This resulted in an increased rate of dissolution and a decreased activation energy for dissolution for the carbonated apatites. Thus, carbonate increased the reactivity of hydroxyapatite.
Get full access to this article
View all access options for this article.
References
1.
Brudevold, F. and Söremark, R.: In Structure and Chemical Organization of Teeth, Vol. 2, Miles, A.E.W., Ed., New York, NY: Academic Press, Inc., 1967, p. 247.
2.
Young, R.A.: Implications of Atomic Substitutions and Other Structural Details in Apatites , J Dent Res53:193-203, 1974.
3.
McConnell, D.: Apatite, New York: Springer-Verlag , 1973.
4.
Cutress, T.W. : The Inorganic Composition and Solubility of Dental Enamel from Several Specified Population Groups, Arch Oral Biol17:93-109, 1972.
5.
Ingram, G.S. : The Role of Carbonate in Dental Mineral, Caries Res7:217-230, 1973.
6.
Legeros, R.Z. : Effect of Carbonate on the Lattice Parameters of Apatite, Nature206: 403-404, 1965.
7.
Featherstone, J.D.B.; Duncan, J.F.; and Cutress, T.W.: A Mechanism for Dental Caries based on Chemical Processes and Diffusion Phenomena During in vitro Caries Simulation on Human Tooth Enamel, Arch Oral Biol24:101-112, 1979.
8.
Voegel, J.C. and Frank, R.M.: Stages in the Dissolution of Human Enamel Crystals in Dental Caries, Calcif Tiss Res24:19-27, 1977.
9.
Arends, J.: Dislocations and Dissolution of Enamel, Caries Res7:261-268, 1973.
10.
Featherstone, J.D.B.; Nelson, D.G.A.; and McLean , J.D.: An Electron Microscope Study of Modifications to Defect Regions in Dental Enamel and Synthetic Apatites , Caries Res (in press).
11.
Wu, M.S. ; Higuchi, W.I.; Fox , J.L.; and Friedman , M.: Kinetics and Mechanism of Hydroxyapatite Crystal Dissolution in Weak Acid Buffers Using the Rotating Disk Method, J Dent Res55:496-505, 1976.
12.
Forward, G.C. : A New Method of Measuring Hydroxyapatite Dissolution Rate, Caries Res11:9-15, 1977.
13.
Allpress, J.G. and Sanders, J.V.: The Direct Observation of the Structure of Real Crystals by Lattice Imaging, J Appl Cryst6:165-190,1973.
14.
Lynch, D.F. ; Moodie, A.F.; and O'Keefe , M.A.: n-Beam Lattice Images V. The Use of the Charge Density Approximation in the Interpretation of Lattice Images, Acta CrystA31:300-307, 1975.
15.
Lynch, D.F. and O'Keefe, M.A.: n-Beam Lattice Images II. Methods of Calculation , Acta CrystA28:536-548, 1972.
16.
Phakey, P.P. and Leonard,Jennifer R.: Dislocations and Fault Surfaces in Natural Apatite,J Appl Cryst3:38-44, 1970.
17.
Patel, P.R. and Brown, W.E.: Thermodynamic Solubility Product of Human Tooth Enamel: Powdered Sample, J Dent Res54: 728-736, 1975.
18.
Weatherell, J.A. and Robinson, C.: Micro-determination of Carbonate in Dental Enamel, Analyst93:244-248, 1968.
19.
Hallsworth, A.S.; Weatherell, J.A.; and Robinson , C.: Loss of Carbonate During the First Stages of Enamel Caries, Caries Res7:345-348, 1973.
20.
Kittel, C.: Introduction to Solid State Physics, 4th ed., New York, NY: John Wiley and Sons, Inc., 1971, Chapter 20.
