The influence of organic-inorganic phase mixtures on degradation behavior of some resin composites used in conservative dentistry

The ability of advanced dental restorative biomaterials to withstand to masticatory forces and permanent changes in the oral environment implies well balanced properties. The aim of this study is to comparatively assess hydrolysis and mechanical behaviour of three nanohybrid filled resin biocomposites with different polymeric matrix content (Experimental composite,"Raluca Ripan" Chemistry Research Institute, Cluj, Romania; Evetric, lvoclar Vivadent; Filtek Z550, 3M ESPE) with a traditional BisGMA/TEGDMA based nanohybrid restorative composite (Herculite XRV Ultra, Kerr). Standardized shaped specimens specifically prepared according to ISO 4049/2000 were subjected to three-point bending test, compression strength test, diametral tensile strength test and to distilled water and artificial saliva water sorption evaluation, respectively. According to statistical analysis the mechanical performance and water sorption ability of the tested materials highlighted different behaviours dependant on the type and distribution of the filler particles, and on the type of different resin matrix monomers mixtures, respectively.