|
Sign In to gain access to subscriptions and/or personal tools.
|
Physical Model for Non-steady-state Dissolution of Dental Enamel
M.V. Patel
Department of Pharmaceutics, University of Utah, Salt Lake City, Utah 84112
J.L. Fox
Department of Pharmaceutics, University of Utah, Salt Lake City, Utah 84112
W.I. Higuchi
Department of Pharmaceutics, University of Utah, Salt Lake City, Utah 84112
The purpose of this study was to provide a rigorous theoretical understanding of the dissolution behavior of dental enamel over the entire time-course of demineralization and to simulate by computer an erosion-type caries lesion according to the physical "hydroxyapa tite model".
The appropriate diffusion equations which accountfor simultaneous diffusion and equilibrium of all species in enamel pores, boundary layer, and bulk solution, and which also take into consideration surface reaction kinetics, were employed to allow for calculation of the micro-environmental solution concentration and changes in the mineral density as a function of time and distance within the enamel. This comprehensive physical model for non-steady-state enamel dissolution also explicitly takes into account changes in the diffusivity and the dissolution rate constant as a function of mineral density. Demineralization experiments were conducted in 0.1 mol/L sink acetate buffer (pH = 4.50, µ= 0.50), with ground bovine dental enamel blocks of known surface area mounted (with beeswax) in a rotating disk apparatus. Mineral density profiles were quantified by means of contact x-ray microradiography. The physical model was used to predict mineral density profiles for given demineralization treatments. The experimental profiles agreed quite well with the predicted profiles, when the effective diffusivity of the enamel was assumed to be a function of porosity and when changes in surface area of the crystallites were taken into consideration.
REFERENCES
- Arends, J. and Davidson, C.L. (1975): HPO42- Content in Enamel and Artificial Lesions, Calcif Tissue Res 18:65-79.[CrossRef][Medline]
[Order article via Infotrieve]
- Bergstrom, D.H. (1985): Inter-crystalline Solution Ion Activity Product Basis of Subsurface Dissolution in a Hydroxyapatite System. Ph.D. Thesis, University of Utah, Salt Lake City, Utah, p. 78.
- Bergstrom, D.H.; Fox, J.L.; and Higuchi, W.I. (1984): Quantitative Micro-radiography for Studying Dental Enamel Demineralization and Remineralization, J Pharm Sci 73:650-653.[Medline]
[Order article via Infotrieve]
- Davis, M.E. (1984): Numerical Methods and Modeling for Chemical Engineers. New York: John Wiley and Sons, pp. 142-144.
- Gantt, D.G.; Silverstone, L.M.; Featherstone, M.J.; and Hicks, M.J. (1984): Structural Comparison of Sound and Demineralized Human and Bovine Enamel, J Dent Res 63: 273, Abst. No. 919.
- Holly, F.J. and Gray, J.A. (1968): Mechanism for Incipient Carious Lesion Growth Utilizing a Physical Model Based on Diffusional Concepts, Arch Oral Biol 13:319-334.[CrossRef][Medline]
[Order article via Infotrieve]
- Larsen, M.J. (1974): Chemically Induced in vitro Lesions in Dental Enamel, Scand J Dent Res 82:496-509.[Medline]
[Order article via Infotrieve]
- Levich, V.G. (1962): Physical Hydrodynamics. New York: Prentice-Hall, Inc., p. 71.
- Losee, F.L.; Cutress, T.W.; and Brown, R. (1974): Natural Elements of the Periodic Table in Human Dental Enamel, Caries Res 8:123-124.[Medline]
[Order article via Infotrieve]
- Miller, W.D. (1905): A Study of Certain Questions Relating to the Pathology of the Teeth, Dent Cosmos 47:18-39.
- Moreno, E.C. and Zahradnik, R.T. (1973): The Pore Structure of Human Dental Enamel, Arch Oral Biol 18:1063-1068.[Medline]
[Order article via Infotrieve]
- Patel, M.V.; Fox, J.L.; and Higuchi, W.I. (1987): Effect of Acid Type on Demineralization Kinetics of Dental Enamel, J Dent Res (in press).
- Sperber, G.H. and Buonocore, M.G. (1963): Effect of Different Acids on Character of Demineralization of Enamel Surfaces, J Dent Res 42:707-723.[Free Full Text]
- Van Dijk, J.W.E.; Borggreven, J.M.P.M.; and Driessens, F.C.M. (1979): Chemical and Mathematical Simulation of Caries, Caries Res 13:169-180.[Medline]
[Order article via Infotrieve]
- Wu, M.S.; Higuchi, W.I.; Fox, J.L.; and Friedman, M. (1976): Kinetics and Mechanism of Hydroxyapatite Crystal Dissolution in Weak Acid Buffers Using the Rotating Disk Method, J Dent Res 55:496-505.[Abstract/Free Full Text]
- Zahradnik, R.T. and Moreno, E.C. (1975): Structural Features of Human Dental Enamel as Revealed by Isothermal Water Vapor Sorption, Arch Oral Biol 20:317-329.[CrossRef][Medline]
[Order article via Infotrieve]
- Zimmerman, S.O. (1966): A Mathematical Theory of Enamel Solubility and the Onset of Dental Caries: III, Bull Math Bio- Phys 28:417-464.
Journal of Dental Research, Vol. 66, No. 9,
1418-1424 (1987)
DOI: 10.1177/00220345870660090201

CiteULike Complore Connotea Del.icio.us Digg Reddit Technorati Twitter What's this?
This article has been cited by other articles:

|
 |

|
 |
 
H.C. Margolis, Y.P. Zhang, C.Y. Lee, R.L. Kent JR, and E.C. Moreno
Kinetics of Enamel Demineralization in vitro
Journal of Dental Research,
July 1, 1999;
78(7):
1326 - 1335.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
X.J. Gao, J.C. Elliott, and P. Anderson
Scanning and Contact Microradiographic Study of the Effect of Degree of Saturation on the Rate of Enamel Demineralization
Journal of Dental Research,
October 1, 1991;
70(10):
1332 - 1337.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
J.M. ten Cate and J.D.B. Featherstone
Mechanistic Aspects of the Interactions Between Fluoride and Dental Enamel
Critical Reviews in Oral Biology & Medicine,
January 1, 1991;
2(3):
283 - 296.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J.S. Chu, J.L. Fox, and W.I. Higuchi
Quantitative Study of Fluoride Transport During Subsurface Dissolution of Dental Enamel
Journal of Dental Research,
January 1, 1989;
68(1):
32 - 41.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
E.I.F. Pearce
On the Dissolution of Hydroxyapatite in Acid Solutions
Journal of Dental Research,
July 1, 1988;
67(7):
1056 - 1058.
[PDF]
|
 |
|
|
|