Physicochemical and biological assessment of flowable resin composites incorporated with farnesol loaded halloysite nanotubes for dental applications

The aim of this study was to fabricate flowable resin composites, by incorporating Farnesol loaded Halloysite Nanotubes (Fa-HNT) as a filler and evaluate their physicochemical as well as biological properties. Chemical and morphological characterization of antibacterial filler, Fa-HNT were performed using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM). The antibacterial filler was mixed into composite material consisting of methacrylate monomers and dental glass fillers at concentrations of 1-20% (wt./wt.). It was observed that addition of mass fractions of Fa-HNT causes enhancement of compressive strength as well as flexural modulus of the composite. However, it significantly decreases flexural strength and degree of conversion. A significant antibacterial activity of dental composite was observed with increase in the area of zone of inhibition against the strains of Streptococcus mutans (S. mutans). There was no cytotoxicity observed by Fa-HNT resin composites on NIH-3T3 (mouse embryonic fibroblast cells) cell lines. A favourable integration of antibacterial filler with significant mechanical properties was achieved at concentrations from 7 to 13 wt% of Fa-HNT in dental composites, which is desirable in dentistry.