Comparison of Solution- and Gel-prepared Enamel Lesions-an in vitro pH-cycling Study

Abstract

A variety of methods has been employed to produce artificial caries-like enamel lesions. The aim of this paper was to use a pH-cycling regime to compare the de-/remineralization behavior of lesions prepared by two methods. Lesions were produced by use of either an acidified undialyzed gelatin system or a buffered solution. Enamel sections, each containing four lesions, were allocated to four groups (A, B, C, D) and subjected to a daily ph-cycling regime of 16-hour demineralization and eight-hour remineralization. Groups A & B contained gelatin-prepared lesions, whereas Groups C & D contained solution-prepared lesions. To the remineralizing solutions used in Groups B & D, 2 ppm fluoride was added. The mineral content in the lesions was assessed, by means of microradiography/microdensitometry, at baseline and at intervals for six weeks. The lesions in all four groups exhibited net demineralization. In terms of the total mineral lost from the lesion (the Δz parameter), the demineralization rates of the solution-prepared lesions were significantly greater than those of the corresponding gelatin-prepared lesions. All sections in the non-fluoride groups showed subsurface demineralization in initially sound enamel, whereas only one section in the fluoride groups showed an area of mineral loss. Laminations in the mineral content profiles were apparent only in Group D. The results of this study indicate that the method of lesion preparation affects the subsequent behavior of lesions when exposed to de- and remineralizing protocols.

Get full access to this article

View all access options for this article.

References

Angmar, B. ; Carlstrom, D. ; and Glas, J.E. (1963): Studies on the Ultrastructure of Dental Enamel. IV. The Mineralization of Normal Human Enamel, J Ultrastruct Res 8: 12-23.

Clarkson, B.H. ; Wefel, J.S. ; and Feagin, F.F. (1986): Fluoride Distribution in Enamel after in vitro Caries-like Lesion Formation, J Dent Res 65: 963-966.

Clarkson, B.H. ; Wefel, J.S. ; and Miller, I. (1984): A Model for Producing Caries-like Lesions in Enamel and Dentin Using Oral Bacteria in vitro, J Dent Res 63: 1186-1189.

Coolidge, T.B. ; Besic, F.C. ; and Jacobs, M.H. (1955): A Microscopic Comparison of Clinically and Artificially Produced Changes in Enamel, J Oral Surg 8: 1204-1210.

Feagin, F.F. ; Clarkson, B.H. ; and Wefel, J.S. (1984): Chemical and Physical Evaluation of Dialyzed-reconstituted Gelatin Surface Lesions of Human Enamel, Caries Res 18: 168-169.

Featherstone, J.D.B. ; Duncan, J.F. ; and Cutress, T.W. (1978): Surface Layer Phenomena in in vitro Early Caries-like Lesions of Human Tooth Enamel, Arch Oral Biol 23: 397-404.

Francis, M.D. and Briner, W.W. (1973): The Effects of Phosphonates on Dental Enamel in vitro and Calculus Formation in vivo, Calcif Tissue Res 11: 81-89.

Holly, F.J. and Gray, J.A. (1968): Mechanism for Incipient Carious Lesion Growth Utilizing a Physical Model Based on Diffusion Concepts, Arch Oral Biol 13: 319-334.

Ingram, G.S. and Silverstone, L.M. (1981): A Chemical and Histological Study of Artificial Caries in Human Dental Enamel in vitro, Caries Res 15: 393-398.

10.

Koulourides, T. (1981): Laminations Caused by Fluoride within in vitro Enamel and Dentin Lesions, J Dent Res 60: 450.

11.

MacDonald, I. ; Creanor, S.L. ; Stephen, K.W. ; and Strang, R. (1986): Comparison of in situ and in vitro Enamel Demineralization Rates, Caries Res 20: 167.

12.

Mellberg, J.R. and Chomicki, W.G. (1983): Fluoride Uptake by Artificial Caries Lesions from Fluoride Dentifrices in vivo, J Dent Res 62: 540-542.

13.

Moreno, E.C. and Zahradnik, R.T. (1974): Chemistry of Enamel Subsurface Demineralization in vitro, J Dent Res 53: 226-234.

14.

Pearce, E.I.F. (1983): A Microradiographic and Chemical Comparison of in vitro Systems for the Simulation of Incipient Caries in Abraded Bovine Enamel, J Dent Res 62: 969-974.

15.

Silverstone, L.M. (1966): The Primary Translucent Zone of Enamel Caries and of Artificial Caries-like Lesions, Br Dent J 120: 461-471.

16.

Sato, K. and Yamamoto, H. (1986): Studies on the Formation of Laminations within Artificial Caries-like Lesions of Enamel, Caries Res 20:40-47.

17.

Strang, R. ; Damato, F.A. ; Creanor, S.L. ; and Stephen, K.W. (1987): The Effect of Baseline Lesion Mineral Loss on in situ Remineralization, J Dent Res 66:1644-1646.

18.

THEUNS, H.M.; VAN DIJK, J.W.E.; DRIESSENS, F.C.M.; and

19.

Groeneveld, A. (1983): Effect of Time and Degree of Saturation of Buffer Solutions on Artificial Carious Lesion Formation in Human Tooth Enamel, Caries Res 17:503-512.

20.

Thylstrup, A. and Fredebo, L. (1982): A Method for Studying Surface Coatings and the Underlying Enamel Features in the Scanning Electron Microscope. In: Surface and Colloidal Phenomena in the Oral Cavity: Methodology, R.M. Frank and S.A. Leach , Eds., London: IRL Press , pp. 169-184.

21.

Von Bartheld, F. (1961): Membrane Phenomena in Carious Dissolution of the Teeth, Arch Oral Biol 6:284-303.

22.

Weatherell, J.A. ; Robinson, C. ; and Hallsworth, A.S. (1983): Formation of Lesions in Enamel using Moist Acid Vapour. In: Demineralisation and Remineralisation of the Teeth, S.A. Leach and W.M. Edgar , Eds., Oxford: IRL Press, pp. 225-241.