The interaction between surface roughness of resin composites and Streptococcus mutans biofilms in various conditions of saliva and different carbohydrate sources

Abstract

I. ObjectivesThe purpose of this study was to investigate the interaction between surface roughness of resin composites and biofilm formation by Streptococcus mutans with different carbohydrate sources under various conditions of saliva.II. Materials & MethodsThe composite resin disks (Filtek supreme Z350, 3M ESPE, USA) were made on the #400 or #800 grit SiC papers or glass slides used as a template and the surface roughness were measured by confocal laser microscopy. Adhesion assays were performed using Streptococcus mutans UA159 with each specimen in the presence of fluid-phase or surface-adsorbed unstimulated whole saliva (UWS) for 3 hours. For biofilm formation, S. mutans was grown with each specimen in a biofilm medium with either glucose or sucrose in the presence of fluid-phase or surface-adsorbed UWS for 24 hours. The adherent bacteria were then detached by sonication and serial diluted and plated on the BHI (Brain Heart Infusion) agar followed by incubation for 2 days. Colony forming unit per unit area (CFU/cm2) of S. mutans was counted.III. ResultsThe results showed that the adhesion and biofilm formation of S. mutans were significantly influenced by the surface roughness of the composite resin in any condition of UWS (unstimulated whole saliva) and carbohydrate sources (P<0.05). There was no significant difference in the interaction effect between surface roughness and saliva treatment (P>0.05). IV. ConclusionThis study suggests that the adhesion and biofilm developments by S. mutans are significantly influenced by the surface roughness of composite resins, irrespective of the condition of saliva and carbohydrate sources for less than 24 hours.