Functional Relationship between Sucrose and a Cariogenic Biofilm Formation.
Sucrose is an important dietary factor in cariogenic biofilm formation and subsequent initiation of dental caries. This study investigated the functional relationships between sucrose concentration and Streptococcus mutans adherence and biofilm formation. Changes in morphological characteristics of the biofilms with increasing sucrose concentration were also evaluated. S. mutans biofilms were formed on saliva-coated hydroxyapatite discs in culture medium containing 0, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, or 40% (w/v) sucrose. The adherence (in 4-hour biofilms) and biofilm composition (in 46-hour biofilms) of the biofilms were analyzed using microbiological, biochemical, laser scanning confocal fluorescence microscopic, and scanning electron microscopic methods. To determine the relationships, 2nd order polynomial curve fitting was performed. In this study, the influence of sucrose on bacterial adhesion, biofilm composition (dry weight, bacterial counts, and water-insoluble extracellular polysaccharide (EPS) content), and acidogenicity followed a 2nd order polynomial curve with concentration dependence, and the maximum effective concentrations (MECs) of sucrose ranged from 0.45 to 2.4%. The bacterial and EPS bio-volume and thickness in the biofilms also gradually increased and then decreased as sucrose concentration increased. Furthermore, the size and shape of the micro-colonies of the biofilms depended on the sucrose concentration. Around the MECs, the micro-colonies were bigger and more homogeneous than those at 0 and 40%, and were surrounded by enough EPSs to support their structure. These results suggest that the relationship between sucrose concentration and cariogenic biofilm formation in the oral cavity could be described by a functional relationship.
Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Jian-Na
JN
Cai
Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Ji-Eun
JE
Jung
Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Minh-Huy
MH
Dang
Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Mi-Ah
MA
Kim
Department of Oral Biochemistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Ho-Keun
HK
Yi
Department of Preventive Dentistry, School of Dentistry, Institute of Oral Bioscience, Chonbuk National University, Jeonju, Republic of Korea.
Jae-Gyu
JG
Jeon
D001422:Bacterial Adhesion / Q000187:drug effects* / Q000502:physiology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D003731:Dental Caries / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D013295:Streptococcus mutans / Q000502:physiology*; D013395:Sucrose / Q000494:pharmacology*
D011135:Polysaccharides, Bacterial; D013395:Sucrose