Electronic Thesis and Dissertation Repository


Master of Science


Medical Biophysics


Dr. Amin Rizkalla


Flowable composites are widely used in dentistry. However, they suffer from poor mechanical properties. The aim of this study was to reinforce a flowable composite with TiO2 nanotubes (n-TiO2), which were synthesized using an alkaline hydrothermal technique then functionalized with silane or methacrylic acid (MA). The synthesized n-TiO2 was characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Electron microscopy revealed a tubular morphology of n-TiO2. Commercially available flowable composite was reinforced with varying amounts of nanotubes (0-5%). Dynamic Young’s moduli (E) and fracture toughness (KIC) of composites reinforced with 3% n-TiO2 functionalized with MA exhibited the highest values. Cytotoxicity assays, performed on NIH/3T3 fibroblasts revealed excellent biocompatibility. We conclude that flowable composites reinforced with 3% n-TiO2 exhibited superior mechanical properties to those of control, with a minimum effect on flowability and radiopacity. Thus, these reinforced composites represent promising materials for use in dental restorations.