Development of high performance dental resin composites with outstanding antibacterial activity, high mechanical properties and low polymerization shrinkage based on a SiO2 hybridized tetrapod-like zinc oxide whisker with CC bonds

Abstract

Outstanding antibacterial activity, low polymerization shrinkage and high mechanical properties are key requirements for dental resin composites (DRCs), however, they are difficult to be simultaneously obtained, and becomes the bottleneck for developing DRCs. Herein, a new kind of functional zinc oxide whisker (ZnOw) with CC bonds, coded as SK-ZnOw, was synthesized by grafting SiO₂ on the surface of ZnOw using the Stöber method. Then SK-ZnOw was embeded into commercial dental resin (dimethacrylate resin, UBT) to fabricate a novel kind of DRCs (SK-ZnOw/UBT). The structure and comprehensive performances including degrees of conversion, polymerization shrinkages, antibacterial activity and mechanical properties of SK-ZnOw/UBT composites were systematically investigated. The results show that SK-ZnOw/UBT composites have simultaneously excellent and durable antibacterial activity, higher mechanical properties and lower polymerization shrinkages than both UBT resin and ZnOw/UBT composites. Especially, for the SK-ZnOw/UBT composite containing 20 wt% SK-ZnOw, its antibacterial rate and that of sample after storage in distilled water at 37 °C for 20 days are as high as 98.1% and 93.7%, respectively; moreover, its flexural strength, flexural modulus and Vickers hardness are about 1.3, 1.1 and 1.4 times those of corresponding values of ZnOw/UBT composite with 20 wt% ZnOw. Meanwhile the polymerization shrinkage of the former is only 0.8 times of that of the latter, clearly demonstrating that the bottleneck of traditional DRCs in literature has been solved. The outstanding performances of SK-ZnOw/UBT composites suggest that the method provided herein is facile and effective to develop novel functional fillers and high performance DRCs.