Characterization of polymicrobial biofilms from carious dentin lesions

Abstract

The monoculture of specific species is a limited methodology because not mimetize the complexity of dental biofilms and not represent the existing natural diversity. The study of polymicrobial biofilms is an alternative to using the biofilms of monospecies and the source of microorganisms for the growth of biofilms is saliva. However, the use of saliva instead of carious dentin as inoculum for cariogenic biofilms growth has been criticized, because the microbiota present in the cavitated carious lesions can be more pathogenic than those present in saliva. Until now, no data regarding the characteristics of polymicrobial biofilms formed in vitro from carious dentin compared to polymicrobial biofilms formed from saliva. Therefore, the objective of this study is to validate the use of saliva or carious lesions in dentin as inoculum for polymicrobial biofilm formation in vitro. For growth of polymicrobial biofilms, samples of infected dentin and saliva from three previously selected donors will be used and the samples will be combined and frozen at -80 ° C until the moment of use. Aliquots of these samples will be added to the McBain broth supplemented with 0.5% sucrose. The biofilms will grow on the surface of glass in a abundance-misery regime, alternating between periods of supplementation and culture medium without addition of sugar, during 4 days. At the end of the experimental period, biofilms will be analyzed for the microbial composition, susceptibility to chlorhexidine and acidogenicity. (AU)