Strong antibacterial dental resin composites containing cellulose nanocrystal/zinc oxide nanohybrids

Abstract

ObjectiveThe aim is to explore the reinforcing and antibacterial effect of cellulose nanocrystal/zinc oxide (CNC/ZnO) nanohybrids on dental resin composites (DRCs). MethodsCNC/ZnO nanohybrids were prepared through precipitating Zn2+ on the surface of CNC and then introduced into the DRCs. The mechanical properties of DRCs including compressive strength, flexural modulus, flexural strength, and Vickers microhardness were characterized. The antibacterial activity of DRCs to Streptococcus mutans was determined and the morphology of Streptococcus mutans on the surface of DRCs after incubation was observed. The morphology of fractured surface after flexural test and Zn content in DRCs were analyzed. ResultsCompared with DRCs without CNC/ZnO nanohybrids, DRCs containing 2 wt.% CNC/ZnO nanohybrids possess higher compressive strength and flexural modulus and there is no significantly statistical difference (P＞0.05) on the flexural strength and Vickers microhardness. The excess use of CNC/ZnO nanohybrids decreases the mechanical properties of DRCs except flexural modulus. DRCs containing CNC/ZnO nanohybrids show excellent antibacterial properties and a 78% reduction in bacterial number is obtained when 2% CNC/ZnO nanohybrids are added. ConclusionThe small amounts of CNC/ZnO nanohybrids have a positive influence on the mechanical and antibacterial properties of DRCs. SignificanceThe prepared DRCs are promising to address bulk fracture and secondary caries.