Effects of Bio-Aging on Mechanical Properties and Microbial Behavior of Different Resin Composites

Under challenging oral environments, the overall performance of resin composites is affected by bio-aging. This study investigated effects saliva biofilm-induced bio-aging on mechanical properties and microbial behavior with different filler types. Microhybrid, nanohybrid, nano-filled flowable were bio-aged biofilm for 30 days. Surface morphology, roughness, aesthetic determined. A 48 h model was used to evaluate in vitro. Biofilm metabolic activity, lactic acid production live/dead bacterial staining tested. Six volunteers selected wear intra-oral appliances composite slabs 24 biofilms collected analyzed using 16S rRNA sequencing assess formation over those materials situ. Although there increasing trends, surface water resorption material solubility had no significant changes all groups after (p > 0.05). There elastic modulus aging However, a decrease flexural strength observed < 0.05), except nanoflow group The Vickers hardness remained stable showed distinct color compared micro-hybrid activity vitro increased slightly groups, but statistical significance Shannon index diversity situ decreased while difference shown species composition at genus level Resin sized fillers displayed relatively uncompromised both days Based results, types can be flexibly according clinical needs. longer time still needed confirm behaviors long run.