Production of Potassium Titanate Whisker Reinforced Dental Composites

Abstract

Potassium titanate (K2O.nTiO2) whiskers (KTWs) were produced by sol-gel method and embedded into UDMA-TEGDMA resins to produce KTW reinforced composites that could be used for both anterior and posterior fillings. The effect Ti/K molar ratio on the chemical, structural and functional properties of the KTWs was investigated using XRD, HR-TEM, and BET analysis. Morphology and the surface properties of the KTWs rely on the Ti/K ratio. However, HR-TEM studies clarified that the KTWs grow along [110] axis regardless of Ti/K ratio. BET analysis revealed the presence of slit shaped meso-pores in the KTWs. The KTW reinforced composites were produced by mixing UDMA-TEGDMA resins at molar compositions of 30-70, 70-30, and 50-50 wt%, and by embedding 5 wt% KTW homogeneously into the mixtures. Photocatalytic activity of the KTWs and the KTW reinforced composites were evaluated through Methylene Blue degradation test. Photocatalytic activity of the composites decreased as Ti/K ratio is increased although it showed a tendency to increase in the KTWs with increasing Ti/K ratio. Meanwhile, the photocatalytic activity of the composites was superior to unreinforced resin mixtures. Mechanical properties namely, nanoindentation hardness and wear-rate of the bulk polymers enhanced significantly by KTW reinforcement.