Biodegradatation of dental composite materials. in vitro stud

Recently, many studies confirm that multispecies oral biofilms can induce structural and topographic damage to the integrity of the composite restorations. Composite restorations can provide a
substrate for attachment of oral biofilms, and it is important to know the dynamics of biofilm formation and whether there are differences between microbial populations on the restoration surfaces and natural tooth structures. It is also important to know whether oral biofilms have effect on the lifespan of composite restorations in the mouth, either directly, by degrading the composite, or indirectly, by attacking the interface between composites and oral tissues.

Aim: The aim of this study is to apply an experimental biofilm formation model for in vitro investigation of the microbial biodegradation of composite materials

Results: The experimental model (CDC Biofilm reactor) produced reproducible biofilms that were representative of the oral microbiota. The in vitro incubated composite samples showed increased micro-roughness and altered surface topography, viewed on scanning electron microscopy. The latter is indirect prove that the bacterial colonization of composite surfaces leads to irreversible damage of the composite organic matrix. These findings serve to suggest that a similar process in vivo should be expected.
Key words: biodegradation, oral biofilm, composite materials, biofilm reactor

Dr. Kostadin Georgiev, PhD