Comparison of periodontitis-associated oral biofilm formation under dynamic and static conditions

Abstract

PurposeThe purpose of this study was to compare the characteristics of single- and dual-species in vitro oral biofilms made by static and dynamic methods.MethodsHydroxyapatite (HA) disks, 12.7 mm in diameter and 3 mm thick, were coated with processed saliva for 4 hours. The disks were divided into a static method group and a dynamic method group. The disks treated with a static method were cultured in 12-well plates, and the disks in the dynamic method group were cultured in a Center for Disease Control and Prevention (CDC) biofilm reactor for 72 hours. In the single- and dual-species biofilms, Fusobacterium nucleatum and Porphyromonas gingivalis were used, and the amount of adhering bacteria, proportions of species, and bacterial reduction of chlorhexidine were examined. Bacterial adhesion was examined with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).ResultsCompared with the biofilms made using the static method, the biofilms made using the dynamic method had significantly lower amounts of adhering and looser bacterial accumulation in SEM and CLSM images. The proportion of P. gingivalis was higher in the dynamic method group than in the static method group; however, the difference was not statistically significant. Furthermore, the biofilm thickness and bacterial reduction by chlorhexidine showed no significant differences between the 2 methods.ConclusionsWhen used to reproduce periodontal biofilms composed of F. nucleatum and P. gingivalis, the dynamic method (CDC biofilm reactor) formed looser biofilms containing fewer bacteria than the well plate. However, this difference did not influence the thickness of the biofilms or the activity of chlorhexidine. Therefore, both methods are useful for mimicking periodontitis-associated oral biofilms.

Antimicrobial effect of toothbrush with light emitting diode on dental biofilm attached to zirconia surface: an in vitro study

“…27 We recently compared in vitro oral biofilms made by static and dynamic methods with F. nucleatum and P. gingivalis and discovered that the dynamic method (CDC biofilm reactor) formed looser biofilms containing fewer bacteria than the static method (well plate). 28 However, both methods are useful for mimicking periodontitis-associated oral biofilms. In this study, the mean log CFU/mL of biofilms in the dynamic method group were lower than those in the static group, but no significant difference was observed in the level of cell growth between the two methods.…”

Relevance of Biofilm Models in Periodontal Research: From Static to Dynamic Systems

“…Similarly, biofilm models can be grown on a static system, being more reproducible and economical, although they hardly reproduce the physico-chemical conditions of the oral environment. Conversely, the dynamic systems enable a continuous nutrient supply, control of the flow and shear conditions or continuous monitoring of the microenvironment, including temperature and pH, among other factors [ 57 ].…”

At the Interface of Materials and Microbiology: A Call for the Development of Standardized Approaches to Assay Biomaterial-Biofilm Interactions

“…Accordingly, the concentration of bacteria used in an initial inoculum can have a profound impact on the biophysical characteristics of the resulting biofilm and thus affect its behavior when grown on a test substrate. Likewise, biofilm behaviors can vary tremendously depending on whether they are formed in a static or flowing environment (Song et al 2017). The most clinically relevant in vitro assay system would incorporate a constant flow of ~0.5 mL/min to mimic saliva production as well as nutrient pulsing to replicate the normal eating habits of the host.…”