This Article Free Full Text (Free PDF) Free References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Dawes, C. Articles by Dibdin, G.H. Search for Related Content PubMed PubMed Citation Articles by Dawes, C. Articles by Dibdin, G.H. Social Bookmarking                         What's this?

A Theoretical Analysis of the Effects of Plaque Thickness and Initial Salivary Sucrose Concentration on Diffusion of Sucrose into Dental Plaque and its Conversion to Acid During Salivary Clearance

Department of Oral Biology, Faculty of Dentistry, University of Manitoba, 780 Bannatyne Ave., Winnipeg, Canada R3E OW3

G.H. Dibdin

MRC Dental Unit, The Dental School, Lower Maudlin Street, Bristol, England BS1 2LY

A mathematical model, written in FORTRAN, has been developed to simulate the interrelated processes of salivary sucrose clearance from the mouth, diffusion of sucrose into dental plaque, and conversion of sucrose to acid and glucan. Reaction of acid with enamel is not included in the model. A total of 28 parameters can be varied by the user, and the relative importance of the different factors affecting acid formation can be assessed. The output of the program gives sucrose and acid concentrations and pH at different depths within the plaque. The initial variables studied were plaque thickness, the salivary sucrose concentration, and the duration of exposure of the plaque to sucrose.

Stephan curves typical of those recorded in vivo were generated by the model. With any particular salivary sucrose concentration, there was an optimum plaque thickness at which a minimum pH was achieved at the enamel surface, with very thin or thick plaque samples producing a smaller pH fall. With thick plaque, the minimum pH was often not achieved at the inner surface but at some intermediate depth, which may explain the location of early caries lesions in fissures. The extent of the pH fall at the inner surface and the duration of the pHminimum region of the Stephan curve were directly related to the initial salivary sucrose concentration and to the duration of exposure to sucrose prior to normal salivary clearance. Simulation of a water rinse at as short a time as two min after the beginning of normal salivary sugar clearance showed that this procedure had only a very small effect on the shape of the Stephan curve. Thus, the maximum salivary sucrose concentration achieved prior to normal salivary clearance appears to be a major factor which determines the extent of the pH fall at the enamel surface of the plaque.

Journal of Dental Research, Vol. 65, No. 2, 89-94 (1986)
DOI: 10.1177/00220345860650021701


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				D.T. Zero In Situ Caries Models Advances in Dental Research, November 1, 1995; 9(3): 214 - 230. [Abstract] [PDF]

				W.M. Edgar and S.M. Higham Role of Saliva in Caries Models Advances in Dental Research, November 1, 1995; 9(3): 235 - 238. [Abstract] [PDF]

				G.H. Bowden The Role of Microbiology in Models of Dental Caries: Reaction Paper Advances in Dental Research, November 1, 1995; 9(3): 255 - 269. [Abstract] [PDF]

				G.H. Dibdin, C. Dawes, and L.M.D. Macpherson Computer Modeling of the Effects of Chewing Sugar-free and Sucrose-containing Gums on the pH Changes in Dental Plaque Associated with a Cariogenic Challenge at Different Intra-oral Sites Journal of Dental Research, August 1, 1995; 74(8): 1482 - 1488. [Abstract] [PDF]

				F. Lagerlof Caries-Protective Factors in Saliva Advances in Dental Research, July 1, 1994; 8(2): 229 - 238. [Abstract] [PDF]

				C.H. Sissons, T.W. Cutress, M.P. Hoffman, and J.St.J. Wakefield A Multi-station Dental Plaque Microcosm (Artificial Mouth) for the Study of Plaque Growth, Metabolism, pH, and Mineralization Journal of Dental Research, November 1, 1991; 70(11): 1409 - 1416. [Abstract] [PDF]

				L.M.D. Macpherson and C. Dawes Effects of Salivary Film Velocity on pH Changes in an Artificial Plaque Containing Streptococcus oralis, After Exposure to Sucrose Journal of Dental Research, September 1, 1991; 70(9): 1230 - 1234. [Abstract] [PDF]

				G.H. Dibdin Plaque Fluid and Diffusion: Study of the Cariogenic Challenge by Computer Modeling Journal of Dental Research, June 1, 1990; 69(6): 1324 - 1331. [Abstract] [PDF]

				W.M. Edgar and S.M. Higham Plaque Fluid as a Bacterial Milieu Journal of Dental Research, June 1, 1990; 69(6): 1332 - 1336. [Abstract] [PDF]

				J.R. Mellberg, I.D. Petrou, and N.E. Grote The Effect of Plaque Thickness on Progression of Artificial Caries Lesion Formation in situ Journal of Dental Research, March 1, 1990; 69(3): 865 - 867. [Abstract] [PDF]

				C. Dawes An Analysis of Factors Influencing Diffusion from Dental Plaque into a Moving Film of Saliva and the Implications for Caries Journal of Dental Research, November 1, 1989; 68(11): 1483 - 1488. [Abstract] [PDF]

				J.R. Mellberg, I.D. Petrou, M. Deutchman, and N. Grote The Effects of 1% Pyrophosphate and 0.02% Sodium Fluoride on Artificial Caries Lesions in vivo Journal of Dental Research, December 1, 1988; 67(12): 1461 - 1465. [Abstract] [PDF]

				G.H. Dibdin and R.P. Shellis Physical and Biochemical Studies of Streptococcus mutans Sediments Suggest New Factors Linking the Cariogenicity of Plaque with its Extracellular Polysaccharide Content Journal of Dental Research, June 1, 1988; 67(6): 890 - 895. [Abstract] [PDF]

				R.F. Wilson and F.P. Ashley The Effects of Experimental Variations in Dietary Sugar Intake and Oral Hygiene on the Biochemical Composition and pH of Free Smooth-surface and Approximal Plaque Journal of Dental Research, June 1, 1988; 67(6): 949 - 953. [Abstract] [PDF]

				R.P. Shellis and G.H. Dibdin Analysis of the Buffering Systems in Dental Plaque Journal of Dental Research, February 1, 1988; 67(2): 438 - 446. [Abstract] [PDF]

				P. Lecomte and C. Dawes The Influence of Salivary Flow Rate on Diffusion of Potassium Chloride from Artificial Plaque at Different Sites in the Mouth Journal of Dental Research, November 1, 1987; 66(11): 1614 - 1618. [Abstract] [PDF]

				L.M.C. Collins and C. Dawes The Surface Area of the Adult Human Mouth and Thickness of the Salivary Film Covering the Teeth and Oral Mucosa Journal of Dental Research, August 1, 1987; 66(8): 1300 - 1302. [Abstract] [PDF]

				F. Lagerlof, A. Oliveby, and J. Ekstrand Physiological Factors Influencing Salivary Clearance of Sugar and Fluoride Journal of Dental Research, February 1, 1987; 66(2): 430 - 435. [Abstract] [PDF]