Effect of divalent ions on cariogenic biofilm formation
- PDF / 2,151,922 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 5 Downloads / 208 Views
RESEARCH ARTICLE
Open Access
Effect of divalent ions on cariogenic biofilm formation Elena Laura Steiger1†, Julia Rahel Muelli1†, Olivier Braissant2, Tuomas Waltimo1 and Monika Astasov-Frauenhoffer3*
Abstract Background: Divalent cations are able to interact with exopolysaccharides (EPS) and thus are capable to modify the structure and composition of dental biofilm. At the moment, little is known about the adsorption of metals by cariogenic EPS; thus, the aim of the present study was to evaluate the effect of divalent ions (calcium, magnesium, and zinc) on the growth and biofilm formation of mutans streptococci and on the dissolution of hydroxyapatite as well as to investigate their binding to the bacterial EPS. Results: S. mutans strains used in this study show the highest tolerance towards calcium of the ions tested. Growth parameters showed no differences to control condition for both strains up to 100 mM; revealing natural tolerance to higher concentration of calcium in the surroundings. Although excessive levels of calcium did not impair the growth parameters, it also did not have a positive effect on biofilm formation or its binding affinity to EPS. Magnesium-saturated environment proved to be counterproductive as strains were able to dissolve more Ca2+ from the tooth surface in the presence of magnesium, therefore releasing excessive amounts of Ca2+ in the environment and leading to the progression of the disease. Thus, this supports the idea of self-regulation, when more Ca2+ is released, more calcium is bound to the biofilm strengthening its structure and however, also less is left for remineralization. Zinc inhibited bacterial adhesion already at low concentrations and had a strong antibacterial effect on the strains as well as on calcium dissolution; leading to less biofilm and less EPS. Additionally, Zn2+ had almost always the lowest affinity to all EPS; thus, the unbound zinc could also still remain in the surrounding environment and keep its antimicrobial properties. Conclusion: It is important to maintain a stable relationship between calcium, magnesium and zinc as excessive concentrations of one can easily destroy the balance between the three in cariogenic environment and lead to progression of the disease. Keywords: Caries, Biofilm, Mutans streptococci, Divalent ions
Background Dental caries is one of the most frequent infectious multifactorial diseases worldwide, characterized as a progressive dissolution and demineralization of tooth structure; when left untreated it can lead to an impaired * Correspondence: [email protected] † Elena Laura Steiger and Julia Rahel Muelli contributed equally to this work. 3 Department Research, University Center for Dental Medicine (UZB), University of Basel, Mattenstrasse 40, 4058 Basel, Switzerland Full list of author information is available at the end of the article
quality of life [1–3]. The development depends on various aspects e.g. personal and social-economic factors (e.g. education, knowledge, behavior, income), genetic and environmen
Data Loading...
