In situ evaluation of the dental material degradation by dental biofilm

Abstract

The dental biofilm can biodegrade the surfaces of restorative materials and to adapt to changes in the oral environment. However, few is known about the precise structure of the biofilm and how it interacts with the restorative material, being a challenge to control its growth by antimicrobial agents or other strategies. This study will evaluate, in situ, biofilm/restorative material interactions through quantitative and qualitative analyses. Ten discs of each material analyzed (IPS Empress 2 - control, Filtek Supreme; Vitremer; Ketak molar Easymix; Tytin) will be made in a metal matrix of 5.0mm x 2.0mm. Roughness and microhardness of each specimens will be initially evaluated. Ten volunteers will be selected to use palatal devices containing specimens of each experimental group. The experiment will consist of two phases: first, the volunteers will use the palatal devices for 48 hours and in the second phase, for 14 days. After the experimental periods, laser microscopy confocal analyses will be performed to visualize the architecture and viability of the biofilm. The images will be analyzed using COMSTAT software, which will allow the evaluation of bio-volume, roughness coefficient and biofilm surface/volume ratio. In addition, the restorative materials will be analysed after interaction with the biofilm, using scanning electron microscopy (MEV), energy dispersive spectroscopy (EDS), roughness and final hardness tests. All the data will be submitted to statistical analysis. (AU)